ML20127E258
| ML20127E258 | |
| Person / Time | |
|---|---|
| Site: | Farley  |
| Issue date: | 01/12/1993 |
| From: | Hoffman S Office of Nuclear Reactor Regulation |
| To: | Hairston W SOUTHERN NUCLEAR OPERATING CO. |
| References | |
| RTR-REGGD-01.127, RTR-REGGD-1.127 NUDOCS 9301190227 | |
| Download: ML20127E258 (24) | |
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..s% UNITED STATES
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l 3"., , , 'j NUCLEAR REGULATORY COMMISSION WAptlNGTON, D. C. 20555 8.
January 12, 1993
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Docket Nos. 50-348 and 50-364 Mr. W. G. Hairston, 111 Executive Vice President Southern Nuclear Operating Company, Inc.
Post Office Box 1295 Birmingham, Alabama 35201-1295
Dear Mr. Hairston:
SUBJECT:
STORAGE POND DAM SAFETY AUDIT AT THE JOSEPH H. FARLEY NUCLEAR PLANT, UNITS 1 AND 2 This letter is to confirm arrangements for a safety audit to be performed by the Nuclear Regulatory Commission (NRC) staff and our technical advisor, the.
Federal Energy Regulatory Commission (FERC), for the storage pond dam and dike at the Joseph M. Farley Nuclear Plant. The audit is scheduled for February 2 and 3, 1993. The dates and scope of the audit have been coordinated with Mr. Brad Moore of your staff.
The audit will focus on the safety of the dam and dike including the operation, maintenance, and any emergency planning aspects based on the potential dambreak hazard downstream of the facility. The audit will evaluate conformance of the facility to the Federal Guidelines for Dam Safety, June 1979 (Enclosure 1), various NRC guidance documents relevant to dam safety, and other documents incorporated into the Proposed NRC Dam Safety Program, April 1991 (Enclosure 2), such as NRC Regulatory Guide 1.127, " Inspection of Water-Control Structures Associated With Nuclear Power Plants."
The audit team will consist of approximately six to seven members, including personnel from the Office of Nuclear Reactor Regulation, Office of Nuclear Materials Safety & Safeguards (NRC Dam Safety Program coordinators), Region II, and FERC. The audit will focus on the storage pond dam and dike, service water intake structure, and the surrounding areas. Access will not be required to other areas of the plant.
A meeting will be held with your representatives the morning of February 2, 1993, to discuss the design, operation, maintenance, inspection, and performance to date of the storage )ond dam and dike, it is requested that a representative be available who is (nowledgeable in these areas. In addition, someone knowledgeable of the design and operation of the service water and river water makeup systems and their interaction with the storage pond should also be available. Following this entrance meeting, the team will perform a field examination.
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9301190227 930112 /,
Mr. W. G. Hairston ,
i The audit is anticipated to be completed in 1 day but may require a second day l depending on the length of the entrance meeting and the field activities. At i the completion of the audit, an exit meeting will be held with your site l personnel to discuss the results of the team's review. j If there are any questions, please contact me.
Sincerely,
- f. 2 [*
l Stephen T. Hoffman, Project Manager Project Directorate 11-1 Division of Reactor Projects - 1/11 Office of Nuclear Reactor Regulation
Enclosures:
I 1, federal Guidelines for i Dam Safety l
- 2. Proposed NRC Dam Safety Program cc w/ enclosures: !
See next page N
- - _. ___m.. ,- _ _ __.- _-.__. - - _ _ . _ . _ _ . _
4 Mr. W. G. Hairston, 111 Joseph M. Farley Nuclear Plant Southern Nuclear Operating Company, Inc.
CC; Mr. R. D. Hill, Jr. State Health Officer General Manager - Farley Nuclear Plant Alabama Department of Public Health Southern Nuclear Operating 434 Monroe Street Company, Inc. Montgomery, Alabama 36130-1701 P.O. Box 470 Ashford, Alabama 36312 Chairman Mr. B. L. Moore Houston County Commission -
Manager, Licensing P.O. Box 6406 Southern Nuclear Operating Dothan, Alabama 36302 Company, Inc.
P.O. Box 1295 Regional Administrator, Region 11 Birmingham, Alabama 35201-1295 U. S. Nuclear Regulatory Commission 101 Marietta Street, Suite 2900 James H. Miller, 111, Esq. Atlanta, Georgia 30323 Balch and Bingham P.O. Box 306 Resident inspector 1710 Sixth Avenue North U.S. Nuclear Regulatory Commission Birmingham, Alabama 35201 P.O. Box 24 - Route 2 Columbia, Alabama 36319
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January 12, 1993 Mr. W. G. Hairston The audit is anticipated to be completed in I day but may require a second day depending on the length of the entrance meeting and the field activities. At the completion of the audit, an exit meeting will be held with your site personnel to discuss the results of the team's review.
If there are any questions, please contact me.
Sincerely, ORIGINAL SIGNED BY:
Stephen 1. Hoffman, Project Manager Project Directorate 11-1 Division of Reactor Projects - 1/11 Office of Nuclear Reactor Regulation
Enclosures:
- 1. federal Guidelines for '
Dam Safety
- 2. Proposed NRC Dam Safety Program cc w/ enclosures:
See next page plSTRIBUTJ0tJ:
Docket file NRC/ Local PDRs PD 11-1 Reading S. Varga G. Lainas E. Adensam S. Hoffman S. Little OGC J. Greeves 6-H-3 R. Shewmaker 5-E-2 l G. Bagchi 7-H-15 R. Pichumani 7-H-15 ACRS (10)
L. Plisco, E00 E. Merschoff R-II
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OfC LA:PQ20 :DRPE PM:PQ2MAPE NMM5, !) EChA D: lhb NAME SLfN1e SHohn:as Jh[ eves- ,IBagcbi EAdensam
! DATE 01/'l /93 01/ 7 /93 dl/[/93- 01/[/93 01/ / l/93 flLENAME: Audit.Ltr
v Docket Nos.60-348 and 50-364
.Mr. W. G. Nairston, 111 Executive Vice President-Southern Nuclear Operating Company, Inc.
Post Office Box 1295 Birmingham, Alabama 35201-1295
Dear Mr. Hairston:
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SUBJECT:
ISSUANCE OF AMENDMENT NO. TO FACILIT_Y OPERATil LICENSE NO.
NPF-2 AND AMENDMENT NO. TO FACILITY OPERATJ LICENSE NO - l NPF-8REGARDINGFIREPROTECTION-JOSEPNM.Ff(LEYHUCLEARPLANT, UNITS 1 AND 2 (TAC N05. M79873 AND M79874)
The Nuclear Regulatory Commission has issued the iclosed Amendment No.
to Facility Operating License No. NPF-2 and Ame dment flo, to facility Operating License No. NPF-8 for the Joseph M- :arley Nuclear Plant, Units 1 and 2. The amendments change the Technica pecifications in response to-your subnittal dated February 26, 1991, as su., emented on May 6, 1991.
The amendments revise the fire prote ion license conditions of the Facility Operating Licenses and relocate th > fire protection Technical Specifications to plant procedures and to the Fi al Safety Analysis Report, in accordance with the guidance provided in C ieric Letters 86-10 and 88-12.
Your february 26, 1991, let r also requested our review of proposed revisions to the Safety Evaluations upporting issuance of Exemption Request Nos. 1-38~
and 2-35 to the requirem its of 10 CFR Part 50, Appendix R. As discussed in-the enclosed Safety Ev uation, we have found the revisions to be acceptable and that they do not (fect the exemptions as granted.
A copy of the rel, ed Safet.y Evaluation is enclosed. A Notice of Issuance will be include in the Commtssion's bi-weekly Federal Reaister notice.
Sincerely, Stephen T. Hoffman, Project Mar,ager Project Directorate 11-1 Division of Reactor Projects - !/11-Enc osures: Office of Nuclear Reactor Regulation
- 1. Amendment No. to NPF-2
- 2. Amendment No, to NPF-8
- 3. Safety Evaluation cc w/ enclosures:
See next page O b.
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tr NAME St8ttle SHoffman:tms CMcCracken EAcensam DATE 12//4 /92 12/ll /92 12/h/92 12/ /92 -12/ /92 Document Name: FAR79873.AMD
Enclosure'2 w
d PROPOSED U.S. NUCLEAR REGULATORY COMMISSION (NRC)
DAM SAFETY PROGRAM PLAN APRIL 1991 INTRODUCTION This plan describes the manner in which NRC will implement the " Federal Guidelines for Dam Safety" (Federal Guidelines), dated June 25, 1979, directed for implementation by the President of the United States on October 4, 1979.
This plan defines the general methodology and mechanisms that vill be used to- -
fully initiate and maintain a Dam Safety Program consistent with the Federal ;
Guidelines. Portions of the plan adopt existing NRC guidance documents _
procedures, and approaches that conform with the Federal Guidelines. Once the plan is implemented, portions of the plan may need to be expanded where existing NRC policy is identified as not fully meeting the Federal Guidelines.
ORGANIZATION AND ADMINISTRATION To meet the objective of ensuring that management and technical-decisions-during all pro,iect stages give proper recognition to safety-considerations, it is necessary to have an organization and management philosophy that continuously strives to improve practices and procedures associated with the regulation of dam planning, engineering, construction, testing, inspection,-
operation, maintenance, re-evaluation, and emergency planning and procedures.
NRC will have a Dam Safety Officer (D50), appointed by the Executive Director for Operations (EDO) and reporting to the Director, Office of Nuclear Material Safety and Safeguards, responsible for ensuring-implementation of the Dam Safety Program, in conformance with the Federal Guidelines. The DSO will be responsible for developing-guidance documents, procedures, training programs, and other aspects necessary for adequate program implementation. The individual'0ffice Directors will be responsible for. implementing the program by regulating their specific licensees. .These responsibilities will be. carried-out through the efforts of Office Directors' representatives to the Dam Safety.
Advisory Group. The group's membership will consist of individuals from the affected NRC offices, and_will include regional office representation where a significant need exists for coordination.or implementation. - Each office represented as a result-of that office's responsibility for the regulation of licensees who design, construct, own, or rperate dams sha11'have a-manager, at least a branch chief, designated by the Office Director / Regional Administrator as the responsible manage;, within that office, for implementation of the 4
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program. In addition, each office shall have a technical member, on the Advisory Group, who is trained in one of the basic disciplines related to dam safety. The DSO will ensure that all necessary disciplines related to dam safety are represented on the Advisory Group. Additionally, the General Counsel shall designate a representative from that office to provide legal guidance to the DSO. The Advisory Group will-meet together at least four times annually and meet with the EDO at least once annually. The charter for the NRC DSO is provided as Attachment A.
The execution of the details necessary to ensure compliance with the Federal Guidelines is expected to be carried out with the aid of the Federal Energy Regulatory Comission (FERC), through a Tet.hnical Assistance effort.
A Memorandum of Agreement (M0A), between FERC and NRC, will )rovide for FERC assistance, through its Office of Hydrupower Licensing, so t1at NRC can proceed to fully implement the Federal Guidelines. Attachment B provides an example of such an H0A that has been executed between the FERC and the Department of Energy (DOE), to ensure that the inventory of DOE dams will be reviewed against the Federal Guidelines.
Under such an agreement, NRC staff will provide the project management function by completing such activities as setting forth criteria and guidelines, defining candidate dams / impoundments for review, setting priorities for work activities and directing FERC activities, including coordination with NRC 1,censees. FERC will perform dam safety inspections and evaluations of dams identified by NRC to determine any areas of non-compliance. Additionally, FERC will perform consulting work, including criteria review and followup inspections. In general, FERC activities will be in accordance with the FERC program for the safety of water power projects, as modified in NRC criteria and guidance.
To execute this program, NRC staffing will generally consist of one individual in each affected NRC office being responsible for identifying the dams to be reviewed and for interfacing with the FERC personnel executing the detailed work. (In some cases, the review conducted may be only to determine whether a specificdamshouldbeconsideredundertheFederalGuidelines.) It is recommended that these NRC individuals also be the same individuals designated by each of the affected offices to serve as the technical representative to the Dam Safety Advisory Group. Based on the experience of FERC, one individual for each 5 to 10 dams appears to be a necessary resource level to fully execute a program on an annual basis, consistent with the Federal Guidelines. It is expected that the combined NRC and FERC resource needs should reflect a similar level.
NRC program-implementation personnel will use the Training Aids for Dam Safety (TADS) Program, initiated by the Interagency Committee on Dam Safety. This will consist of a study-training program directed by the NRC 050. In addition, NRC personnel involved in program implementation will be encouraged to attend dam-safety training offered through other government agencies, professional groups, and universities.
4-3 The FERC personnel who may be involved in support of the NRC program implementation will be drawn from a staff that FERC believes is fully competent in the fields of hydrology, hydraulics, geology, and geotechnical and structural design, as well as in t teld inspecuons and investigations.
Currently, training of FERC personnel combines the use of TADS, and courses by other Federal agencies, by professional organizations and universities, and 1 by outside consultants, for agency use.
DAM INVENTORY AND HAZARD CUSSIFICATION NRC has provided, in NUREG-0965, a basic inventory of dams associated with nuclear power plants and uranium mill-tailings dams. That information was current as of February 1,1982; changes in the actual inventory have occurred mainly as a result of power plant cancellations and "ranium mill closings.
Dams or impoundments associated with the facilities used by various other NRC licensees were not addressed. Certain dams may constitute dams that should be considered under the Federal Guidelines either on the basis of dam height, impounded water volume, or potential significant downstream hazard.
Attachment C provides the definition of the term " dam," based on the Federal Guidelines. The definitions of " hazard" and " hazard classifications" are also in Attachment C and reflect a composite of the definitions being used by the Federal Guidelines, FERC, and the Bureau of Reclamation of the Department of Interior.
Based on these definitions, it will be necessary for the NRC to query or inspect the various licensees, to ascertain whether a dam or impoundment exists, at their licensed utilization facilities, that ir radiologically safety-related, and integral to the operation of the facility. In addition, it will be necessary to determine if any other dams exist for the facility or the. process that are non-radiologically safety-related. The results of this effort and any subsequent followup will be used to update the NRC Dam Inventory to define those dams that should be considered under the Federal Guidelines and to define the responsible regulatory agency, if any. The initial information needed to determine whether a dam should be considered under the Federal Guidelines, as well as relevant information on the regulatory authority for the dam, if any, will be obtained from various licensees. This survey will be conducted over a period of time, on the bases of the type of facility and the type of license the licensees possess.
Once a list of radiologically safety-related dams and tailings dams that should be considered under the Federal Guidelines has been established, priority groupings of the facilities will be established, based on the :urrently available information. These groupings will be used as guidance in the scheduling of the reviews and inspections under the Federal Guidelines and the NRC Dam Safety Program. The priority assigned to a' specific dam will be based on considering such items as the downstream hazard, age of the dam, type of dam, information on the design and designers, and past performance history, as well as any operational or inspection information. Owner information on State or local regulation of the dam may also be used in prioritization.
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CRITERIA AND TECHNICAL GUIDANCE Currently, NRC uses reguletory guides, standard review plans, and branch technical positions to provide the necessary detail to ensure that the existing regulations are met and that dams (radiologically safety-related) designated as selsmic Category I or for use as retention systems for uranium mills are designed, constructed, inspected, and operated to the safety level expected by NRC. Included in these documents are guidance documents such as the following:
Regulatory Guide 1.59, " Design Basis floods for Nuclear Power Plants,"
Rev. 2, 8/77, with Errata published 7/30/80.
Regulatory Guide 1.60, " Design Response Spectra for Seismic Design of kuclear Power Plants," Rev. 1, 12/73.
Regulatory Guide 1.127, " Inspection of Water-Control Structures Associated with huclear Power Plants," Rev. 1, March 1978.
Regulatory Guide 3.11 " Design, Construction, and Inspection of Embanknent Retention Systems for Uranium Mills," Rev. 2, 12/77.
Regulatory Guide 3.11.1, " Operational Inspection and Surveillance of Embankrent Retention Systems for Urarium Mill Tailings," Rev. 1, 10/80.
These guidance documents will be evaluated for consistency with the Federal Guidelines, as well as with the supplamental technical guidance documents that have been published by Interagency Ccamittee of Dam safety (1C005). The evaluation will address the design bases for the dam, the design, construction, testing, and inspection processes, as well as the operation, maintenance, and surveillance programs that must function during the life of the facility. The specific ICODS technical guidance to be used in evaluating current NRC guidance will consist of the following two documents:
"forFederal Dams," Guidelines by ICODS, and forpublished Selectingbyand Accommodating)
FEMA (undated . Inflow Design Floods "Feoeral Guidelines for Earthquake Analysis and Design of Dams," by 1C005 and published by FEHA, as FEHA 65/ March 1985.
Whenever instances of conflict are identified and the current NRC requirements or guidance documents are less restrictive than those of the Federal Guidelines, NRC will consider changing its requirements and/or guidance to be consistent with the Federal Guidelines. If the r ederal Guidelines are not met and no changes are made, NRC will provide a justification for the lesser margin of safety.
lI 4-5 If changes f rom current NRC regulatory requirements or guidance result from this process, the various NkC licensees will be appropriately notified and given a timetable for the implementation of the Dam Safety Program and any revisions thereto.
INSPECTION AND REHABit.lTATION Once the criteria and guidelines have been clearly defined, or redefined, it will be necessary for NRC, as the regulator of radiologically safety-related cams and mill tailing dams, to conduct inspections of the licensees' dams, related programs, and actions taken by the licensees, as well as to review documents and data important to the safety of the dams. The inspection criteria, frequency, and scope of the inspections shall, as a minimum, meet the Federal Guidelines.
The frequency and scope of the inspections will be the resultant of those inspections conducted by the dam owners, combined with those of NRC, as the regulatory agency and those conducted by a State, if conducted under an acceptable dam-safety program. Recognition of State dam-safety programs as the regulatory control will only be made after a formal Memorandum of Understanding has been executed between a specific State and NRC.
Where inspection findings and any subsequent analyses define inadequate margins of safety regarding dam failure, NRC will require the owner to undertake a rehabilitation program to upgrade the safety of the dam. The schedule for completion of such upgrades will stem from case-by-case review.
EMERGENCY ACTION PLANNING All licensees with radiologically safety-related dams or mill tailings dams that are to be addressed under the Federal Guidelines and that are classified as significant- or high-hazard dams shall develop emergency action plans for them. The plans, as a minimum, shall confom with the Federal Guidelines and any other guidance NRC may provide.
NRC, in defining what is necessary for adequate emergency planning, will use the " Emergency Action Planning Guidelines" issued by 10005 in February 1985.
To the extent possible, emergency action plans for dam safety will use elements of existing radiological emergency action plans that have been developed by the various licensees.
Emergency action-plan elements shall address: determination o' the mode of failure of a dam; definition of the inundation zone, and classes of danger within the inundation zone; time available for response; notification methods and requirements; evacuation plans; availability of men and material for remedial actions; provisions for increased frequency of inspection / observations; the consideration of various predefined action statements; and the necessary training of operation personnel.
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REMEDIAL ACTION AflD DAM FAILURES NRC will maintain a data base of instances where remedial action was necessary, as well as any cases of operational incidents and dam f ailures. The DSO will define the data necessary for inclusion in the data base, but as a minimum, the following information shall be available in the data base:
Dam identification and location Dam owner and operator Date of occurrence Precursory events such as rainfall, seismic event, etc.
Description of event Time scenario of event Actions taken Losses in terms of dollars, injuries, and deaths Cause of event Relationship of event to Dam Safety Program Future actions needed INDEPENDENT REVIEWS AND MANAGEMENT REVIEWS Under this program, independent reviews, at various stages in the life cycle of a dan, from inception to subsequent removal, will be a necessary. By nature, the concept of the owner performing the major functions of, and addressing the elements of, a dam-safety program, with regulatory agency overview will meet the 9061 of the Federal Guidelines. Forexistingdams,theFederalGuIdelines prescribe formal inspections at intervals not to exceed five years. For this program, owners will have to have such reviews and inspections conducted by a team of qualified individuals, with a majority of the menbers being independent of the owner's organization. .
The effectiveness of the NRC Dam Safety Program in implementing the Federal Guidelines will be assessed by HRC management. Additionally, the EDO, in preparation for, or as a result of, the annual meeting with the Dam Safety Advisory Group, may conduct management reviews on the status of program implementation.
DAM-SAFETY PROGRAMS OF STATE AGENCIES This program recognizes the existence of dam-safety programs under the jurisdiction of various States' designated agencies for State dam safety. It will be necessary for NRC to enter into a Memorandum of Understanding with any State for a dam that has been incorporated into the NRC Dam Safety Program, if NRC is to accept the State's dam-safety program and actions taken under it.
NRC will provide a basis for the acceptability of the State's program. In cases where a State is an NRC Agreement State, the necessary provisions for addressing dam safety can be incorporated into the agreement documents.
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For those licensees whose license is for a utilization facility, it is necessary that the governing requirements f or dam saf ety of a radiologically safety-related dam be those defined in this program. Section 274c(1) of the Atomic Energy Act 42 U.S.C. 2021(c), prevents NRC from relinquishing any authority to e State for the regulation of the construction or operation of a utilization facility. Therefore, the regulatory framework of this program would govern. States could, however, after entering into a Hemorandun of Understanding with !1RC, conduct such inspections and evaluations as defined in this program, in this situation, NRC would have to take any remedial or enforcement actions precipitated by a State inspection.
SPECI AL INITI AT!VES Old DAM SAFETY The 050 will be responsible for annual review, of and identification to the EDO of, any dam-safety areas that are part of this progran, where special emphases or initiatives are necessary to improve dam safety.
Based on agency-wide priorities for resources and an evaluation of the relative needs in the total NRC programs and budget, the EDO will authorize any justified special initiatives in dam safety. The DSO will develop a schedule and plan for completion of any initiatives and report at least annually, to the EDO, on the status of the efforts and the target completion date.
REVISIONS TO THIS PLAN The DSO will be responsible for advising the EDO and the Commission on the need for revisions to this plan. Evaluation of the need for revision shall be conducted at intervals not to exceed two years and shall incorporate consideration of comments received f tom the Federal Emergency Management -
Administration (FEliA), on program implementation, based on the most recent biennici report by FEPA. There may be shorter times between revisions, if -
necessary.
Attachments:
A. Charter of HRC Dam Safety Officer B. Example of FERC Memorandum of Agreement C. Definitions
CHARTER - DAM SAFETY OFFICER (Revision 2, October 1990)
BACKGROUND The " Federal Guidelines for Dam Safety"* direct that each Federal Agency having responsibility for design, construction, operation, or regulation of dams establish a dam safety officer or officer reporting directly to the head of the agency or the head's designated representative. The purpose of this charter is to identify the duties and responsibilities of the Nuclear Regulatory Commission (NRC) Dam Safety Officer.
RESPONSIBILITY The Dam Safety Officer is responsible for ensuring that the NRC, as a matter of policy and actual practice, makes every responsible and prudent effort to assure the safety of dams which are subject to NRC regulations. Generally, the duties of the Officer include:
- " Federal Guidelines for Dam Safety," Federal Coordinating Council for Science, Engineering and Technology, AD Hoc Interagency Commission on Dam Safety, Washington, D. C. 20500, June 25, 1979.
(1)SubstantiveChangestoJuly 11, 1980, Charter (2) Substantive Changes to January 1983 Charter Attachment A
.. 2 (1) development and implementation of an NRC Dam Safety Program Plan, addressing the relationship to the Federal Guidelines for Dam Safety; (2) surveillance and evaluation of NRC practices related to dam safety concerning design and construction of new dams, operation, maintenance, and rehabilitation of existing dams, including emergency planning and procedures; (3) recommending and coordinating implementation of improvements in these practices when evaluation reveals safety-related deficiencies; and (4) advising tha Executive Director for Operations (EDO) of significant needs and weaknesses of the NRC dam safety program, as necessary.
The recommendations and programs of the Dam Safety Officer shall be consistent with the regulatory nature of the NRC.
APPOINTMENT AND REPORTING The Dam Safety Officer is appointed by the EDO at the recommendation of the Director, Office of Nuclear Material Safety and Safeguards (NMSS), and keeps the Director, HMSS, informed on routine matters of dam safety. The Officer also reports to the EDO periodically on p ogram status and has direct access to the EDO on dam safety matters to the extent necessary to execute the responsibilities of the Dam Safety Officer.
FUNCTIONAL STATEMENT The NRC Dam Safety Officer:
- 1. Requests each NRC office involved with dams to nominate a representative to a Dam Safety Advisory Group, as necessary, to coordinate dam safety matters between their respective offices and the Dam Safety Officer. ]
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- 2. Serves as Chairperson for the Dam Safety Advisory Group.
- 3. Develops and implements a Dam Safety Program Plan to address the Federal l Guidelines for Dam Safety.
- 4. Maintains an inventory of dams. -
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1
- 5. Coordinates research needs unique to NRC dam safety efforts.
- 6. Prepares progress reports, as necessary, advising the EDO on the status of the NRC dam safety efforts.
- 7. Revises this charter, as necessary, to plan for the future. The revision is to be coordinated with the budget call to insure the dam safety program is reflected, as required, in the budget.
- 8. Ensures that the activities identified in " Responsibility" are accomplished.
- 9. Serves as NRC contact on dam safety with the Federal Emergency Management Agency (FEMA). -
- 10. Serves as the NRC representative on the Interagency Comittee on Dam Safety (ICODS).
PROJECTED ACTION ITEMS Tne Dam Safety Officer will:
- 1. Convene the Dam Safety Advisory Group as necessary to involve individual Offices in dam safety matters.
- 2. Encourage active comunication among the Comission's staff responsible for dam safety on matters related to site investigation and design, construction, and operation and maintenance (including emergency action planning) for dams, and related research, as outlined in the Federal Guidelines for Dam Safety.
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- 3. Keep a current account of the status of the NRC dem safety program as it relates to the Federal Guidelines for Dam Safety.
4 Prepare and present to the Commission an NRC Dam Safety Program Plan proposing an overall NRC policy with respect to NRC involvement in the regulation of dams.
S. Prepare and maintain a current NRC inventory of dams.
- 6. Develop a licensee reporting program and an internal communication program to insure the NRC is aware of incidents related to dam safety.
- 7. Develop a plan, including manpower and budget impacts, for the implementation of the Federal Guidelines for Dam Safety.
B. Coordinate the NRC dam safety program with other Federal agencies through participation in the ICCDS.
- 9. Coordinate the NRC dam safety program with various states, as appropriate, and maintain contact with the Association of State Dam Safety Officials ( ASD50).
- 10. Report to FEMA as requested on a biennial basis to provide input for the FEMA biennial report to the President on the status of implementation of the Federal Guidelines on Dam Safety.
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l Memorandum of Agreement between the Federal Energy Regulatory Cornission and the Department of Energy Regarding Dam Safety Inspections and Evaluations of Department of Energy Dams Federal agencies periodically report to the Federal Emergency Management Agency (FEFA) on progress in implementing the Federal Guidelines for Dam Safety.
FEFA has recomended that the Department of Energy (00E) obtain the assistance of the Federal Energy Regulatory Comission (FERC) to review its DOE dam safety program. DOE has requested such assistance. In order to conduct complete evaluations and inspections of DOE dams, the FERC and the DOE hereby enter into this agreement, to provide for FERC assistance to enable the 00E to fulfill DOE's responsibility for safety at DOE dams. This agreement deletes and supercedes all previous agreements. Under this agreement, the FERC, though its Office of Hydropower Licensing, Will perform dam safety inspections and evaluations of the DOE dams to determine any areas of non-compliance with the Federal Guidelines for Dam Safety, to detemine adherence to current engineering design criteria, and to provide consultative services and perform follow up inspections as necessary to ensure that any recommended remedial measurer, are properly implemented. The FERC assistance will be generally in acccrdance with the FERC program for safety of water power projects and project works set out in 18 CFR Part 12. The DOE will annually reimburse the FERC for FERC's full cost of providing all assistance to the DOE.
There are at least 24 DOE dams that are under the responsibility of four different DOE offices:
Office Number of Dams Rocky Flats Office 6 Dak Ridge Operations Office 8 Richland Operations Office 1 Savannah River Operations Office 9 Total 24 The DOE dams are located in seven States and are operated by 00E contractors. Attached is a list of the DOE dams, including their location and other pertinent data. The list may be revised from time to time as the need arises. The contractors operating the dams are managed by DOE offices located in Rocky Flats, Colorado; Dak Ridge, Tennessee; Richland, Washington; and Savannah River, South Carolina.
ATTACHMENT B
2 Part 1 The FERC and the 00E agree as follows:
- 1. The FERC Division of Dam Safety and Inspections will conduct the inspection and evaluation of DOE dams consistent with the FERC dam safety program. The initial inspection on each dam will be an Operation Inspection which will cover operation and maintenance, dam safety review, hazard potential classification, and assessment of routine inspection procedures by operating personnel for each facility. The Operation Inspection Report, furnished by the FERC to the DOE, will include recommendations for any tollow-up required for maintenance for dam safety purposes. Follow up action could include such items as remedial measures, field and/or laboratory investigations, further engineering consultations, and emergency action plans.
The FERC will provide its inspection repcrts and safety recommendations to the appropriate office with a copy to the Assistant Secretary, Environment, Safety, and Health. Activities necessary for follow up action will be the responsibility of the appropriate DOE offices. Operation Inspections will be performed each year on each high or significant hazard potential dam and at 2 s to 3 year intervals for dams having a low hazard potential classification.
Additional inspections will be perfomed by the FERC if warranted by dam safety concerns.
- 2. Investigations and analyses that are required will be reviewed by the FERC consistent with the FERC Engineering Guidelines. To properly implement any necessary dam safety remedial measures, meetings will be held as necessary by the FERC with engineering consultants retained by the DOE offices to provide further engineering analyses and evaluation. When construction work begins on any necessary remedial measures, the FERC will perfom construction inspections to ensure that construction is in accordance with contract plans and specifications and that sound construction practices, satisf actory field supervision, and adequate quality control (in accordance with FEAJ dam safety regulations) are being employed. prior to construction.
FERC will review plans and specifications and the construction quality control program and provide comments and recomendations thereon to the appropriate DOE office. The number of construction inspections will be dependent upon the complexity of construction aspects and various construction features involved.
Before inspection, the FERC will notify the appropriate DOE office of the date, time, and purpose of the inspection.
- 3. DOE will provide, or cause its contractors to provide, to FERC all data, reports, drawings, plans, or other information that is, in the FERC's opinion, necessary or appropriate for review of dam safety.
- 4. The FERC and the DOE will, as necessary, establish procedures by which the inspection work and dam safety review planned in any year will be estimated and properly costed to establish the necessary funding required to be furnished by the DOE each year.
I l
F 5. The FERC and the DOE will establish a procedure to transfer funds from the DOE to the FERC to reimburse FERC for its full costs of the implementation and continuation of the dam safety inspections and dam safety review and evaluations. The procedure shall also provide for the determination of and requirements for any additional funding necessary within any year, should an emergency or unusual condition be determined.
6 If the DDE should dispute any safety recorrendations made by the FERC staff, the question will be referred for resolution by the Director, Office of Hydropower Licensing, for the FERC, and by the Assistant Secretary, Environment, Safety, and Health, for the 00E.
- 7. Investigations, tests, analyses, monitoring, and remedial work (including sny emergency action plans) as provided in the inspection reports and safety recomendations shall remain the responsibility of DOE. The DOE will promptly undertake all such actions.
Part II This agreement shall become effective on the last signature date below, and shall remain in effect until it is terminated or renegotiated upon request by either party. If either party finds that its terms need to be modified or amended, the other party shall be notified in writing of the specific change (s) desired, with proposed language, and the reason (s) therefor. A proposed change shall become effectivc upon written mutual consent of both parties, and shall then become a part of this agreement.
< AW ^ [ t ,
Red E. SpringEV /
Paul L. Zie g fti.D.
Director, Office of Hydropower Assistart Secretary Licensing, Federal Energy Environa. ant, Safety and Health Regulatory Comission Department of Energy
[a &'
23,1990 SEP 1 4 1990 (Date) (Date)
$George e L. sL ph ratt A
/ ~
Executive Director, Office of Executive Director, Federal Energy Regulatory Comission 9h7/9e
~
f (DAer ~
l l
9 r Table 1 DDE DAMS State lleight Storage Dam Field Offices Dam (ac-ft) @
(feet)
A-2 CD 36 19 E Rocky Flats Plant 43 E A-3 CO 42 A-4 CO 52 97 E 00 57 79 E B-5 E CD 43 71 C-2 Sanitary Landfill CO 46 28 E 01 55 406 E Oak Ridge X-6118 KY 10 96 E Paducch C-616-F ORGDP-K-10018 TN 5 5d E White Oak in 20 240 E South Holding Pond OH 27 45 E IN 62 130 E ,
Y-12 Ash Pond MO 11 90 E Raffinate Pit No.3 250 E Raffinate Pit No.4 HD 17 WA 25 100 E Richland B-Pond SC 60 85,000 E Savannah River Par Pond Lower Das 100,000 E Steel Creek Dam (L Lake) SC 90 SC 40 2,000 E Par Pond B SC 20 2,000 E Pond C SC 25 50 E Pond 2 SC 25 50 CG Pond 2 SC 40 500 E Pond 5 SC 40 500 E Pond 5 SC 40 500 CG Pond 5 E - Earth CG - Concrete Gravity
DEFINITIONS The following definitions apply to the NRC Dam Safety Program.
DAM: A dam is any artificial barrier, including appurtenant works, which 1 pounds or diverts water and meets any one of the three conditions provided below. This definition applies whether the dam has a permanent reservoir or is a detention dam for temporary storage of floodwaters or water associated with some industrial type activity that is used for cooling, a settlement or dewatering basin, or other processes within the facility.
A dam is considered by the NRC Dam Safety Program if it is:
(1) greater than or equal to 25 feet in height with a storage capacity greater than 15 acre-feet, or (2) has a storage capacity greater than or equal to.50 acre-feet and is l
greater than 6 feet in height, or 1
(3) there is a potentially significant downstream hazard.
The height of a dam is the vertical distance measured from the natural bed of the stream or water course measured at the downstream toe of the barrier, or from the lowest elevation of the outside limit of the barrier if it is not across a stream channel or watercourse, to the maximum water storage elevation. The impounding capacity at maximum storage elevation includes storage of floodwaters above the normal full storage elevation of the facility.
l ATTACHMENT C
. 2 DAM FAILURL: A dam failure is characterized by a catastrophic type of failure
]~ produced by the sudden, rapid, and uncontrolled release of impounded water.
It is recognized that there are lesser degrees of failure and that any malfunction or abnorr.ality outside the design assumptions and parameters which adversely affect a dam's primary function of impounding water is properly considered a failure. Such lesser degrees of failure can progressively lead to or heighten the risk of a catastrophic failure. They are, however, normally amendable to corrective action. _
HAZARD: A hazard is present if there is a potential for loss of life or property damage downstream of a dam from floodwaters released at the dam or waters released by partial or complete failure of the dam or overtopping of the dam whether that results from flooding or rim slides into the reservoir. Hazards y are classified with respect to their severity; however, hazard classification is not associated with the existing condition of a dam and its appurtenant structures er the anticipated performance or operation of a dam. Rather, hazard classification is a statement of potential adverse impact on human life, downstream property, or improvements from a large water flow or release from any cause. The hazard classification assigned to a dam is based on consideration of the effects of a dam failure during both norral and flood flow conditions. The cost of the dam, related facilities (e.g., pump -
stations, canals, pipelines, etc.), and the related project losses are not considered in downstream hazard classification. Also, tne consequences of a rapid reservoir drawdown, due to a dam failure, on persons upstream from the dam are not considered in downstream hazard classification. Only the direct effects of a flood on persons, property, or improvements downstream from the dam are considered.
Hazards are classified as follows:
3 DOWNSTREAM HAZARD CLAS$1TICAT10N SYSTEM
]
Lives-in-Classification Jeopar@ Economic Loss Downstream Area Characterization 3 Low 0 Minimal Rural, agricultural area with uninhabited structures, local -
roads, minor improvements, and no outstanding natural features that could be damaged.
Significant 16 Appreciable Rural, agricultural area with scattt: red homes, small industry or employment sites traversed with secondary highways and mireur railroads which if subjected to 3
the hazard could cause the loss of, or interruption of public utilities. Area my contain natural features that may have minor impacts.
High More than 6 Excessive Urban area including residential, business, industry, agricultural, recreational and other centers ~
of work and residence containing important public utilities, main highways, railroads and schools.
Natural features may be heavily impacted.
LIVES-IN-JEOPARDY: Lives-in-jeopar@ is defined as all individuals within the inundation boundaries who, if they took no action to evacuate, would be subject to dangers of varying extremes. The level of danger is based on the degree of protection afforded by the structure the person may be in, the size of the person, the depth of water flow, the velocity of water flow, the time of year, tirse of day, and the season of the flooding.
Whether the people are within the inundation area on a permanent basis vs. a temporary basis will also be a factor in determining itves in jeopar@.
, 4 EC0?iOMIC LOSS: Economic loss is that loss rtsulting from damage to residences,
] cocinercial buildings, industries, croplands, pasturelands, utilities, roads and highways, railroads, etc. Consideration should also be given to economic loss resulting from damage to outstanding natural resources within officially declared parks, preserves, wilderness areas, etc. Also, if a toxic or harmful substance is known to be present in significant quantities in the impoundinent,
] the effect of its dispersion on downstream areas (with respect to economic loss only) should be considered in the downstream hazard classification. __
4 F
. . . ~ . - - _ _ . . ... - - . - . . . .. ... . - .- ,
- 9, , y j .
Enclosure-1 2.
+
FEDERAL GUIDELINES FOR DAM SAFETY
' ~l .
. \.
s Prepared by the .
Ad Hoc Interagency Committee on Dam Safety -
of the ,
FEDERAL COORDINATING COUNCIL FOR SCIENCE, t f H ENGINEERING AND TECHNOLOGY -
- Washington, D.C. 20500 June 25,1979 J
,se
' 4 by the supertmundens et Documenia. U 8. Ommn=3 Panune omne OT@[gppg. si.=C Ciss ,
. s
. ~
^
PREFACE These guidelines represent the culmination of efforts, initiated by President Carter in April 1977, to i review procedures and criteria used by Federal Agencies involved in the design, construction, operation, and regulation of dams and to prepare guidelines for management procedures to ensure dam safety. The guidelines are based on an intensive review of Agency practices conducted by the Departments and Agen cies themselves, by an ad hoc interagency committee of the Federal Coordinating Council for Science,
! Engineering and Technology (FCCSET), and by an Independent Review Panel of recognized experts from
_j the academic and private sectors. These reviews are summarized in two earlier reports: Improving Federal i
Dam Sgfety, a report of the FCCSET, November 1977, and Federal Dom Sgfety Report of the OSTPInde-1 pendent Review Panel December 1978.
Publication of the guidelines marks the final step in the review process. However, the Departments and Agencies recognize that there must be a continuing Federal effort to improve dam safety. Federal dam safety remains a fundamental responsibility of each Federal employee in every Department and Agency in volved and it is on their technical expertise and dedication that the safety of Federal dams rests. These guidelines recogr'te that underlying fact and support management efforts to discharge that responsibilit effectively and efficiently.
These guidelines apply to Federal practices for dams with a direct Federal interest and are not intended .
to supplant or otherwise conflict with State or local government responsibilities for safety of dams under their jurisdiction. Current Federal initiatives to assist States and others with non-Federal dam safety pro-grams are being pursued under other authorities. The objective of both programs is the same, however: to allow the people of this country to enjoy the benefits of water resource development with the best assurance of dam safety possible.
T The members of the FCCSET Ad Hoc Committee are to be commended for their diligent and highly professional efforts. Oratitude and appreciation are aho due the several Departments and Agencies volved for their whole-hearted interest and support.
Frank Press, Chairman Federal Coordinating Council for Science, Engineering and Technology 1 l
- m ,
. -,. =.~n . .- - - n . - - , ~- ~ . . - - , . - . . .
3
- TABLE OF CONTENTS Page
-i Preface.................................................................................ill I. INTRO DU CTI O N . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
A . B A C K G R O UND . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
B. AUTHORITY AND IMPLEMENTATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ,
C. D EF IN ITI O N S . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
II. OBJ ECTIVES AN D SCOPE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
III . G UID ELI N ES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
A. ORG ANIZATION MAN AGEMENT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
- 1. General........................................................................9
- a. Ari m i nistration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ,.
- b. Design Responsibility . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
- c. Construction Responsibility . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
- d. Operation Responsibility . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 4
- e. Technical Coordination . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . '
- f. Emergency Planning . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
- g. Risk- Based A nalysis . . . . . . . . . . . . . . . . . . . . . . . . . . . , . . . . . . . . . . . . . . . . . . . . . . . , . . . . . .
- 2. Sta f fing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
- a. Technica1 Support . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11 b . C om pet ence . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . , . . . . . . .
- c. Continuity . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
- d. Professiona1 Advancement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
3 . Tr aini n g . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
- a. Int ernal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
'b . Academic . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ' . . . . . . . . . . . . . . . . . . . . . . . . . . . . ; 13
- c. ' Pro fessional . . . . . . . . . . . . . . . . . . . . . . . _. . . . . . . . . . . . . . . , . . . . . . . . . . . . . . . . . . . . . . . 13 i
-L
- d. New Technology , . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
- 4. a.Communication ..................................................
Interdisciplinary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . -. . . . . . . . . . . . . . . . . . . . 13
- b. I nteragency . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14 -
l> 5. a.
Documentation ...................................................
Design Recor d . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
- b. Construction Record . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
- c. Initial Reservoir Filling and Surveilknce Record . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
- d. Operation and Maintenance Record . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
- e. Permanent Files . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
- 6. Review s . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
- a. Extent.....................................................................15 b . Interna 1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
- c. Externa 1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
- 7. Research and Development . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 O a. Methods and Materials . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
- b. ' Risk. Based Analysis . . . . . . . . . . . . . . '. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
r
- c. Interagency Coordination . . . . . . . . . . . . . . . . . . . . . : . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17 .
- 8. Contracts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
- a. Documents . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
- b. Modifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ;
- 9. a.
CFunding onstraints ...................................................
for Organizational Managemen1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
- b. Public Concerns . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
4 x y
Y w -
______.___...____.______l___.__.
TABLE OF CONTENTS (Continued)
Page IH, GUIDFLINES (Continued)
B. MANAGEMENT OF TECHNICAL ACTIVITIES - SITE INVESTIGATION AND DESIGN 19
- 1. H ydr o l o g y . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
- a. H azar d Ev alu atio n . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19 b . Flood D ev elo pment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
- c. Flood Selection for Design . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
- d. Hydrologic Design of Reservoir . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19 c . Downstream E f fects . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
- f. W arnin g S yst ems . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
- 2. Earthquake Investigation and Design . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
- a. Investigation F actors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . , 20
- b. Selection of Design Earthquakes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
- c. Engineering Seismology . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . , . 20
- d. Need for Earthquake Analysis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
- e. Seismic and Geologic Studies . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
- f. Design for Earthquake Forces . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
- 3. Geotechnics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
- a. G en er al . . . . . . . . . . . . . . . t . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
' b. Exploration and Identification of Geotechnical Problems . . . . . . . . . . . . . . . . . . . . . . . . . . 21 j c. Geotechnical Design . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22
- d. Foundation Treatment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22
) e. Instrum entation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22
- 3. f. Inspection and Continuing Evaluation During Construction . . . . . . . . . . . . . . . . . . . . . . . . 23
. g. Reevaluation at Existing Structures . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23
- 4. H ydraulle Appurtenances . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23 1 -
- a. General . . . . . . . . . . . . . . . . . . . . ..............................................23 V ' b. Design Flood Releases . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24
~
- c. Oth er W a t er Releases . . . . . . . . . . . . . . . . . . . . . .'. . . . .' . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24
- d. Reservoir E vacuation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24
- e. Control of Flows During Construction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24 4
2
- f. Design Criteria and Guidance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24 j g. Reanalysis Because of Changes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24 4
- h. Hydraulic Design involvement During Life of Structure. . . . . . . . . . . . . . . . . . . . . . . . . . . . 24 j 5. Concrete Dams and Concrete Elements of Embankment Dams . . . . < . . . . . . . . . . . . . . . . . . . . 24
- a. Site S pecific Design . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24
)
- b . M a t erials . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25
- c. Design o f Structures . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25
- d. Definition of Loads . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25
- c. Desi gn M ethods . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25
- f. Design E valuation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25 '
i g. Instrumentation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26 1
- h. Construction and Operational Followup . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26 i
0 6. Embankment D ams . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26 i a. Site Specific Design . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26
, b . M at erials . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26 s c. Design Constructibility . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26
- d. Embankment Design . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26
- c. Instrum entation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27
- f. Construction and Operational Followup . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27
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TABLE OF CONTENTS (Continued)
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III. GUIDELINES (Coatissed) -
C. MANAGEMENT OF TECHNICAL ACTIVITIES - CONSTRUCTION . , . . . . . . . . . . . . . . . 28
- 1. I ntr od uctio n . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
- a. Construction Contracts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
- b. Construction / Design Interf ace . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28 '
- 2. Evaluation During Construction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28
- 3. Orientadon of Construction Engineers and Fleid inspectors . . . . . . . . . . . . . . . . . . . . . . . . . . . 29 '
- a. Desi gn R el ated . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29 R b . Fo un da d o n . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . '
- c. M a t erials . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
d . Construction General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
- 4. Construction Assurance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .)
- a. Construction Procedures . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . , 30 i
- b. Construction Materials Testing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30 J
- c. Qu ality Assuran ce . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30 1 D. MANAGEMENT OF TECHNICAL ACTIVITIES - OPERATION AND MAINTENANCE .31
- 1. Operation and Maintenance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31 )
.; a. General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . g.
- b. Operating Procedu res . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31
]. c. M aintenance Procedures . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
- 2. Periodic Inspection Program . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32
- a. , General . .- . . . . , . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 2
- b. Types and Frequencies of Inspections . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32
- c. ' I nstrumentation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
- d. Correction o f De ficiencies . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
. e. Documentation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . , . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 5
- 3. Emergency Action Planning . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .' . . . .' . . . . . . . . . . . . . . . . . . . .' . 36 a, General . . . . . . . . . . . . . . . . . . . . c ; -. . t m . . . . . . , . . . . . . . r . . . . . . . . . . . . . . . . . . . . . . . . . 36
)
- b. Evaluation of Emergen' e y Potential . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36
- c. Actions to Prevent Failure or Minimize Effects of Failure . . . . . . . . . . . . . . . . . . . . . . . .
- d. ~ Actions Upon Discovery of a Potentially Unsafe Condition . . . . . . . . . . . . . . . . . . . . . . . . . 39 -
4 Page IV. APPENDICES -
A. FCCSET AD NOC INTERAGENCY COMMITTEE MEMBERS . , . . . . . . . . . . . . . . . . . . . . A.1, B. . INTERAGENCY OUIDELINES SUBCOMMITTEE MEMBERS . . . . . . . . . . . . . . . . . .
C. OSTP INDEPENDENT REVIEW PANEL MEMBERS . . . . . . . . . . . . . . . . . . . . . . . . . . .
D. ACKNOWLEDGEMENTS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. . ; . . . . . . . . . . . . . . . . . . . . D-1 E. B I BLIOGRAP HY . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
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i I. INTRODUCTION These guidelines apply to management practices for dam safety of all Federal agencies responsible the planning, design, construction, operation, or regulation of dams. They are not intended as guide or standards for the technology of dams. The basic principles of the guidelines apply to all dams. However, reasonable judgments need to be made in their application commensurate with each dam's size, complex i and hazard.
The Federal agencies have a good record and geaerally sound practices on dam safety. These guidelines are intended to promote management control of dam safety and a common approach to dam safety prac-tices by all the agencies. Although the guidelines are intended for and applicable to all agencies, it is j recognized that the methods of the degre: of application will vary depending on the agency mission I functions.
A. BACKGROUND Throughout history, in all parts of the world, dams built to store water have occasionally failed and discharged the stored waters to inflict sometimes incalculable damage in the loss of lives and great dam to property. Failures have involved dams built witheat application of engineering principles; but ha involved dams built to, at the time, accepted enginecring standards of design and construction. The
- technology of dams has Unproved with the increased knowledge of design principles and of the charneteristics of foundation and dam materials, and it is generally agreed that safe dams
- an be built an i existing dams can be safely maintained with proper application of current technology. It is the inten these guidelines to outline mwngement practices that will help to ensure the use of the best current i technology in the design. construction, and operation of new dams and in the safety evaluation of ex dams.
a As early as 1929, following the failure of the St. Francis Dam, the State of California enacted a dam safety program. Subsequently, other dam failures causing loss of Ilfe and property have prompte tionallegislation on state and national levels.
The Congress in 1972 enacted Public Law 92 367, known as the " National Dam Inspection Act. Th Secretary of the Army was authorized to inspect non-Federal dams ht the nation meedng the sirn storage limitations of the Act to evaluate their safety; report inspection results to the States and ad States on actions needed to emure dam safety; report to the Congress the information given to the S n
- prepare a national inventory of dams; and make recornmendations to the Congress "for a co national program for the inspection and regulation for safety purposes of d:ms of the nation." Reepon sibilities under the law were delegated to the Corps of Engineers. The activities performed under the pro.
U sram consisted of an inventory of dams; a survey of each State and Federal agency's capabiliti .
and regulations regarding the design, construction, operr. don, and maintenance of dams; developrtent of guidelines for ins'pection and evaluatioa of dam safety; and formulation of recommendatia:. for a com-prehensive national program. A report on these activities and proposed legislation to implement a f ederal dam safety program were transmitted to Congress in November 1976, but lack of funding prevented the ex-ecution of the detailed dam inspections. -
"Re failure during initial filling in 1976 of the Teton Dam in Idaho, a Federal earth embankment dam over 300 feet high, reactivated intense public and governmental concern f or dam safety. Congressional and Federal agency inve:tigations were made into this disaster and the entire question of dam safety, and new Federal legislation for dam safety was initiated in the Congress.
An April 23,1977, Presidential memorandum (reproduced in Section I.B) directed federal agencies to review their dam safety practices, addressing many elements of dam safety. Major elements included inter-nal and external review, qualifications of pcrsonnel, integration of new technology, emergency preparedness plans, and review of existing dams. The agencies' reviews and the assessment of the reviews .
by a Federal ad hoe interagency committee and by an Independent Review Panel showed that sound prac- )
tices are generally being used, but concluded that improvement is needed in some management practices for dam safety.
B. AUTHORITY AND IMPLEMENTATION
! , The authority for preparation of these guidelines is contained in a memorandum from President Carter j dated April 23,.1977, which read as follows:
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! . ? ' " MEMORANDUM FOR i 1.;
- The Secretary of the Interior The Secretary of Agriculture. . . . .
The Secretary of the Army The Director, Office of Management and Budget l
x The President's Adviser on Science and '
l' Technology The Chairman, Federal Power Comminion i
The Chairman, Tennessee Valley Authority i The Commissioner, U.S. Section, International 3
Boundary and Water Commission k
The safety of dams has been a principal concern of Federal agencies that are involved with the various aspects of their planning, construction, operation and ultimate disposal.
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Events of the past several years have highlighted the need to review procedures and criteria that are being employed by these agencies with the objective of ensuring that the
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' moet effective mechanisms are established to give the best assurance of dam safety pos-sible within the limitations of the cunent state of knowledge available to the scientific and engineering communities. The safety of such projects should continue to be accorded highest consideration, and it is the responsibility of the head of each agency concerned to
- ensure the adequacy of his agency's dam safety program.
I. Agency Dam Safety Reviews The head of each Federal agency responsible for, or involved with site selection, design, constniction, certification or regulation, inspection, maintenance and operation, repair
,and ultimare disposition of dams shallimmediately undertake a thorough review of prac.
- tices which could affect the safety and integrity of these stru:tures. This review will en-a compass all activities which can be controlled or regulated by the agency.
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Several aspects of the problem require special attention. In particular, the following
- J items should be investigated: the means of inclusion of new technological methods into existing structures and procedures; the degree to which probr.bilistic or risk. based analysis j is incorporated into the process of site selection, design, construction, ano operation; the degree of reliance on in-house, interagency, and outside expert interpretation of geologic data in site selection and design development; the effect on dam safety of earthquake , or other earth movement hazards; the effects of cost.saving incentives on decisions both prior to and during construction; the procedures by which dam safety problems are iden- ,
tified, analyzed and s olved; the involvement of local communities in identifying, analyz- l ing, and solving dam safety questions; and the major outstanding dan' safety problems of the agency.
-II. Interagency Report and Proposed Guidelines i The Chairman of the Federal Coordinating Council for Science, Engineering and Technology (FCCSET) shall convene an ad hoc interagency committee to coordinate dam ;
safety programs, seeking consistency and commonality as appropriate, and providing !
recommendations as to the means of improving the effectiveness of the Government-wide ,
dam safety effort. The agency reviews described above should be provided to the l FCCSET as a basis for the interagency analysis on a timetable established by the FCCSET group as reasonable and consistent with the October 1,1977 deadline for a final report.
Representation on the FCCSET for this activity should be expanded to include other ap- l propriate Federal agencies or departments including, but not limited to, the Tennessee
- Valley Authority, the United States Section-International Boundary and Water Commis-sion and the Federal Power Commission. The FCCSET effort will include preparation of proposed Federal dam safety guidelines for management procedures to ensure dam safety.
, FCCSET should report on all these items. .
.'lII. Iridependent Review Panel In addition, the Director of the Office of Science and Technology Policy will arrange
'for review of agency regulations, procedures and practices, and of the proposed federal dam' safety guidelines, by a panel of recognized experts to be established immediately. The panel will obtain the view s and advice of established organizations, professional societies, and others concerned with the safety of dams which are in any way affected by a Federal role.
The review report thereon should be completed no later than October 1,1978."
(signed) Jimmy Carter The ad hoc interagency committee called for in paragraph II of the memorandum was established FCCSET, under the direction of the Office of Science and Technology Policy. The committee was represented by:
Offlee of Science and Technology Policy (Chairman)
Department of the Army Department of Agriculture Department of the Interior
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Nuclear Regulatory Commmion (NRC)
U S. Section, International Boundary and Water
- Commission (IBWC)
Federal Energy Regulatory Commission (FERC)
(Formerly Federal Power Commbion)-
Tennessee Vallef Authority (TVA) 3 ,
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e The Nuclear Regulatory Commission was added to the dam agencies addressed in the memorandum.
Members of the ad hoc committee are listed in Appendix A.
Also established were subcommittees for the preparation of the proposed Federal dam safety guidelines called for in paragraph 11 of the memorandum. These subcommittees and their task groups had represen-tatives from all the agencies with responsibilities for dams. Appendix B lists the members of the subcom-mittees and task groups and their agencies.
i in accordance with the Presidential memorandum, the participating agencies submitted their reports on review of agency management practices involving dam safety; the subcommittees submitted the proposed Federal dam safety guidelines; and the ad hoc committee prepared the FCCSET report, Improving Federal Dam Sgfety, dated November 15,1977. The report contains summaries of the agency reports, and the sub-committee proposed guidelines and summary thereof; assesses the agency reports; and makes recommen-dations for improvement of management practices for dam safety.
Pursuant to paragraph III of the President's memorandum, the Independent Review Panel was formed with specialists from the academic and private sectors concerned with dams. Members of the panel are listed in Appendix C. The panel reviewed the FCCSET and associated reports and proposed guidelines, and submitted a report, Federal Dam Safety, Report of the OSTP Independent Review Panel, December 6, 1978.
These guidelinet were developed from the FCCSET r port and its proposed guidelines, from Indepen-dent Review Panel recommendations, and with the cooperation of the panel.
C. DERNITIONS The following definitions apply in these guidelines.
< Dam or Projec:. Any artificial barrier, including appurtenant works, which impounds or diverts water,
.' and which (1) is twenty-five feet or more in height from the natural bed of the stream or watercourse measured at the downstream toe of the barrier or from the lowest elevation of the outside limit of the bar-rier if it is not across a stream channel or watercourse, to the maximum water storage elevation or (2) has
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an impouWs capacity at maximum water storage elevation of fifty acre feet or more. Th;e guidelines i _~do not app: a any such barrier which is not in excess of six feet in height regardless of storage capacity, or which has a storage capacity at maximum water storage elevation not in excess of fifteen acre-feet regardless of height. This lower size limitation should be waived if there is a potentially significant
- downstream hazard.
The guidelines apply with equal force whether the dam has a permanent reservoir or is a detention dam for temporary storage of floodwaters. The impounding capacity at maximum water storage elevation in-cludes storage of floodwaters above the normal full storage elevation.
In addition to conventional structures, this definition of " dam" specifically includes " tailings dams,"
embankments built by waste products disposal and remining a disposal pond.
Dam Failure. Catastrophic type of failure charactenzed by the sudden, rapid, and uncontrolled release of impounded water. It is recognized that there are lesser degrees of failure and that any malfunction or ab-normality outside the design assumptions and parameters which adversely affect a dam's primary function of impounding water is properly considered a failure. Such lesser degrees of failure can progressively lead to or heighten the risk of a catastrophic failure. They are, however, normally amenable to corrective ac.
d tion.
Contreet. Contracts relating to project design, construction equipment, operation, or regulation, as ap.
. plicable to the project and the agency function. Where work is described using the terms contract or con-
- tractor, it is meant to include also nimilar work by the agency's own personnel.
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- f Malatensnee. Maintaining structures and equipment in intended operating condition; equipment repaj and minor structure repair. i 1
Rehabilhation or Improvement. Repair of structure deterioration to restore original condition; altera-tion of structures to improve dam stability, enlarge reservior capacity, or increase spillway and outlet ;
works capacity; replacement of equipment. l Hazard. Potentialloss of life or property damage downstream of a dam from floodwaters released at the ;
dam ra waters released by partial or complete failure of the dam, and upstream of the dam from effe rim slides. A hazard is considered significant if there is a potential to cause loss of life or major damage to permanent structures, utilities, or transportation facilities.-
Emergency Preparedness Pisa. Formal plan of procedures to alleviate hazards during constructio after completion of a dam or to reduce damages if conditions develop in which dam failure is likely or un preventable. Thue emergency plans related to dam safety do not include flood plain manageme controlled release of floodwaters for which the project is designed.
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4 IL OBJECTIVES AND SCOPE The overall purpose of these guidelines is to enhance national dam safety. The immediate obje encourage high safety standards in the practices and procedures Federal agencies use or requ they regulate for dam site investigation, design, construction, operation and maintenance, and preparedness. M these guidelines are directly applied to make Federal dams as safe a that they will also influence state dam safety agencies and public and private dam owners to conscious where programs are now weak.
i The guidelines are intended to outline Federal agency management procedures that will c I stimulate technical methods in dam planning, design, construction, and operation for minim failure. The objective of dam safety would be achieved as management and technical decisio project stages give proper recognition to safety considerations, and the strategy of the that end is to describe definite management practices to reinforce decision-maker. awareness l needs. Those charged with adminkterms these guidelines must recosmze that the achievemen is through a continuous, dynamic process in which guidelines, practices, and procedures are periodically and updated. Technical procedures'nebd to change with technological adv management should ensure that observed deficient practices are corrected and that successf duplicated.' .
The goal of making dams as safe as practical implies a limit to maxunum reasonable e sed with implementing these guidelines need to recognize that no dam can ever be because of incomplete understanding of or uncertainties associated with natural (earthquak and manmnde (sabotage) destructive forces; with materials behavior and response to these control of the construction process. Management must ensure that uncertainties are proper with competent technical judgment.
Although dams have been built for thousands of years, dam engineering is not an exact more accurately described as an " art." It is true that this branch of engineering, like any other heavily upon mathematical principles and physicallaws, but every stage of the p1=aning a dam project also requires the c'ercise of experienced judgment. This is true la designin new dams, and especially true in evaluadng and/or improving existing dams. For many of th dams," there is little information available to document original site exploration, design, co and past operation. These dams must be carefull: inspected and observed for indicators of To illustrate a principle from just one aspect of dam design, there are practicallimitations on the amou of physical data that can be obtained during planning and de applying these judgments, Constmetion is a critical phase in achieving a safe dam. Any project must be continuousl
'j' and "re-engineered" as required, during construction to assure that s.
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conditions encountered during construction. Quality of construction is also critical to safety. Deficiencies in materials or construction practices can occur during all stages of the construction, and constant vigilance is necessary to prevent them. Sampling and testing at a completed project cannot be relied on as an effective substitute for inspection and quality control during construction.
Monitoring existing dams and reacting quickly to inadequate performance or to danger signals is a con-tinuing critical aspect for dam safety. Careful monitoring and quick response can prevent failures,in-citiding those caused by poor construction.
The guidelines are Intended to make as small as possible the failure risk hherent in constru: ting new dams, and to prioritize needs to improve existing dams according to hazard potential as estimated by technical analysis and as constrained by financial and personnel resources.
In the development of these guidelines, consideration was given to the broad diversity of agency mis-sions. The guidelines were designed to be free of specific agency policies and unnecessary details. The resul.
tant level of detail in the guidelines represents an attempt to achieve a balance between general manages.
ment goals for assuring dam safety and meaningful principles which can survive technological changes and be useful to the non-Federal community.
A special situation exists regarding the application of these guidelines to dams of international nature.
Several dams of concern to the United States are located partially in the United States and partially in Mex-ico or Canada. Those dams located at the U.S. Mexican border are only partly subject to the jurisdictica of a U.S. Federal agency, the U.S. Section of the International Boundary and Water Commission. In this case, the U.S. should seek agreement with the Mexican Section of the Commission for adoption of ap.
4 plicable sections of these guidelines for ensuring dam safety. For dams located on the U.S.-Canadian
' border, the guidelines should be referred to the U.S. Section of the International Joint Corranission (UC) to seek agreement with the Canadian Section of the Commhslon on means by which the guidelines could j ;be implemented through the entities that are responsible for construction, operation, and maintenance of l
the projects. , ,
. Section Ill.A, Organizational Management, outlines the.clements of agency management respon-sibilities for dam safety. Sections Ill.D, III.C. and Ill.D. Management of Technical Activities, contain ad-
- ' ditional guidance on technical activities for Site investigation and Design, Conrtruction, and Operation
! andMaintenance (includes Periodic inspection Program and Emergency Action Planning). Appendix E is a bibliography of references to related guidelines and practices developed by Federal dam building agencies and other scientific and technical organizations. The body of knowledge represented by the bibliography is intended to be representative of dam techaology, but not inclusive of all available literature that may be helpful.
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III. GUIDELINES A. ORGANIZATION MANAGEMENT
- 1. General Heads of Federal agencies are responsible for the development and implementation of polley
' resources and procedures for safe design, construction, operation, and inspection of each da jurisdiction, as applicable to the agency mission. The agency management structure assi egency in discharging this responsibility and shares in it. The m for assuring that procedures are evaluated and updated periodically,
- s. Administration The head of each Federal agency having responsibility for design, construction, operation, or of dams should estab!1sh a dam safety office (officer) which reports directly to the head of th I
designated representative. The office should be responsible for ensuring that the agency, a policy and in actual practice, makes every reasonable and prudent effort to enhance the_
under its jurisdiction. Duties of the office should include surve of new dams, and operation, maintenance and rehabilltation of e '
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agency dams.
The functions of the office should be advisory to the agency head, and through the agency h agency administrative and technical units. The staffing and detailed duties of the office should surate with the agency mission.
If a Federal dam safety office is established within the recently proposed Federal Emergency M ment Agency (FEMA), the heads of the dam gfety offices in the respective agencies shou FEMA's interagency coordinating functions.
4 The agency organization for the design, construction, operation, or regulation of a dam be structured so that a single identillable, tachnie=11y qualified administrative head has the r
, for assuring that all management and technical safety aspects guidance and direction, and the authority and resources to ensure these responsibilitie Management should ensure that organization staffing is sufficient dand qualified for the workload, and that all programs necessary for the safety of dams are established, continued, a e
realistically funded. Allocation of manpower and funds should givej high ifica- priority to safety-rela tions. Safety-related functions and Icatures must not be sacrified to reduce costs, improve projec tion, or expedite time schedules. l J
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- b. Design Responsibility "
The design function can never be considered finished as long as the dam remains in place; design involve-ment should :ontinue throughout construction and operation of the project. The design office should
- establish specific programs for onsite construction and operational inspection for review by appropriate design personnel and technical specialists. The programs should include frequent and mandatory inspec-tions during construction to confirm that site conditions conform to those assumed for design or to deter.
mine if design changes may be required to suit the actual conditions. A major requirement is inspection and approval of the dam foundation and foundation treatment before placing of dam materials. Final design inspection of the construction should include complete project surveillance, and testing of operating equipment. Operational design inspections should continue throughout the life of the project, in accor-dance with a formal inspection program covering all project features. Management must program ade-quate funds to assure dam safety is not compromised by failure to conduct regular and thorough inspec-tions and reviews.
The design function includes responsibility for planning any dam instrumentation to be installed during construction and/or operation to monitor conditions that could potentially threnten dam safety. The design should identify the purpose of the instrumentation, and include the plans for timely reading, collect-ing, reducing, and interpreting the data. It should include an advance determination of critical instrument observations or rates of data change, and a plan of action if observations indicate a critical condition may occur.
- c. Construction Responsibility l The responsibility for administering construction and supply contracts, for understanding the design and contract intent, for maintaining technical coordination between design and construction engineers, and for managing the construction staff to assure compliance with specifications should be vested in an l identified engineer at the construction project. He should have the administrative and technical control of j all resources necessary to accomplish safe construction of the dam. Construction personnel should under- l stand the conditions upon which the design is based and the relationship between these conditions and the l i
design features. When unanticipated conditions are encountered, design personnel should be involved in
. determining their effect.
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> d. Operation Responsibility"
' The responsibility for project operation should be assigned to a single staff member of the operating orpmntion. He should also handle the operating organization requiremems for coordination with the !
design organization, including reporting changed conditions discovered by operators and participation of the operating organization personnel with design personnel in the periodic inspection program.
4 c. Technical Coordination j All technical specialties required to plan, design, construct, and operate dams to achieve dam safety 4
should be staffed and their efforts coordinated to ensure technical adequacy. A project design engineer should be assigned technical coordination responsibility for each dam. He should handle necessary technical coordination within the agency and with private and public organizations.
Continuing liaison sliould be maintained among the personnel concerned with the various stages of proj-ect development and operation so that each concerned discipline and organizational unit knows and understands the relevant activities of the others. This coordination must be given constant attention to be
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sure proper action is taken.
w f. Emergency Planning An emergency plan should be formulated for each dam. The plan should be in the detail warranted by the size and location of the dam and reservoir. It should evaluate downstream inundation hazards resulting from floods or dam failure, and upstream conditions that might result from major land displacements or increased flood flows, including the effects from failure of upstream dams. - ,,,
Where applicable, the plan should include inundation maps for the flows resulting from design floods g and from possible failure of the dam. The complete emergency plan should be transmitted to appropriate
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v local, state, and Federal governmental bodies. The plan should be periodically reviewed and kep
' date, and periodically publicized to maintain awareness of its existence.
In addition to the emergency plan for the completed dam, a similar plan should be prepared for the con struction period, including area facilities that may remain during the period and floods that may be an ticipated.
- g. Risk Based Analysis Risk based analytical techniques and methodologies are a relatively recent addition to the tools availab for assessing dam safety. With further refinement and improvement, risk. based analyses will probab gain wider acceptance in the engineering profession and realize potential as a major aid to dec in the interest of public safety. However, even when fully developed, risk analyses cannot be used as a substitute for sound professional judgment of engineers, contractors, or review boards. In view of th problems of uncertainty in analysis and possibility of misinterpretation by the public, but in r the high potential these techniques have, agencies should be encouraged to conduct research improve the techniques and to develop the methodologies and base of expertise necessary to app dam safety evaluations. Specifically, agencies should strive to perfect techniques for evaluating the i
bility of possible deficiencies causing dam failure and estimating the potentiallosses due to such a l'~ Meanwhile, the hgencies should evaluate the potential consequences of failure of the dams under t t
jurisdiction. Although the value of potential property losses can be estimated, it is recognized that tial loss of Ilves can only be quantified, but not evaluated. On new dams, potentiallosses can be use l study of project alternatives and in assessment of adultional safety incorporated into the dam fac 4
existing dams, a tisk. based analysis should be considered in establishing priorities for examinin rehabilitating the dams, or for improving their safety.
- 2. Staffing .
- a. Technical and Support Management should assure adequate and competent technical staff'mg to perform the essential la planning design, construction, and operation and maintenance of dams. Technical staff sh supported by administrative, clerical, and other elements to ensure that the technical staff is from technical work. In the planning and design function, particular emphasis should be given to adeq staffing in hydrology, hydraulics, geology, engineering seismology, field investigation, and geo and structural design. Sufficient expertise should be available on the construction staff and on the opera tion staff to maintain an understanding of design decisions related to the various design specialities.
Construction inspection staffing should assure quality as well as quantity inspection coverage. S should be reviewed by higher authority than the local construction office, Field personnel should i trained and experienced if the design is to be implemented and a safe structure is to be constructe
- must not only recognize the need for adherence to the design, but must be able to recognize wh design is at odds with conditions being encountered. The responsibility and importance of th staff to dam safety must be given appropriate consideration in organhetional and position classi decisions.
The operating personnel must be qualified to perform the many functions required in the opera ciuding the recognition of conditions possibly detrimental to dam safety. Operation and maintenan staffing requires careful attention to personnel responsible for operating inspections, and to per participate in the periodic inspection program. It is essential that support personnel and equip provided to accomplish needed maintenance activities. '
t
- b. Competence Job-related experience, professional aptitudes, and educational background should be m evaluating the competence of individuals for the requirements of each responsible position y
the safe design, construction, and operation of dams. All positions should be staffed by compet enginects or specialists in the related disciplines.
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- c. Continuity #
Staffing policies should recognize that continuity of technical positions is essential to maintain consis-tent high standards of practice. This applies in all elements of project development from design to opera-tion, and is especially critical in those positions having supervisory responsibility related to dam safety.
- d. Professional Advancement The agencies should maintain a positive program for advancement of technical personnelin recognition of acquired experience, training and education, and increased competence. It is essential that agencies maintain the technical as well as the managerial expertise required for safe. effective dam design, construc-tion, and operating programs. Organizational structure, position classification, and career incentives must recognize both technical and managerial responsibility and compensate both equitably.
- 3. Training '
- a. Internal To supplement technical staffing, agency management should provide internal personnel training. A rotational training program should be established to familiarize new personnel with all major aspects of the agency functions and the interrelationships of its organizational units. Provisions should be made for technical personnel to observe and participate in decision-making meetings and to make site visits with more experienced staff. Staff members should be allowed to attend consultants meetings in order to gain valuable experience.
Technical personnel concerned with all phases of project development should be given broad exposure to a variety of field conditions. For example, geologists and potechnical personnel shculd gain experience with soil and rock drill crews and in the laboratory testing facilities; design personnel should be familiar with concrete and soll placing and testing techniques; operating personnel should be familiar with equip-
{
ment installation and testing procedures.
j
- A rotational training program should be considered that would place' construction engineers in the
! design organization during' design and design engineers in the field during construction on temporary
^
assignments. Preconstruction training should be provided for-inspection personnel, covering the design engineering considerations and the requirements and importance of thoroughtleid inspection. The training should be given by embankment or structural engineers and geologists assigned from design or by the con-I struction engineers who had received preconstruction orientation by the designers, geologists, and em-I bankment and structural engineers (section llI.A.4.a). This training should make sure that allinspectors know the expected requirements in detail. Onsite instruction sessions for inspection of new features of con-struction should be developed and given by supervisors or lead inspectors before initiation of the work.
Operation and maintenance personnel should be trained by personnel experienced in operation of simdar projects, covering all features of facilities operation and inspection. Thorough training should be provided s
for the personnel who will take observations on and monitor any installed dam instrumentation. The train-ing should be conducted by experienced observers and by the engineers responsible for analyzing the struc-ture effects revealed by the instrumentation data.
T:whmmny qualified operating personnel should be trained in problem detection and evaluation, and application of appropriate remedial (emergency and nonemergency) measures. This is essential for proper evaluation of developing situations at alllevels of responsibility which, initially, must be based on observa-tions made by trained operating personnel at the project. The training should cover the problems that ex-perience has shown are most likely to occur with the type of dam and facilities, and include the kinds of y monitoring best suited to early detection of those problems. Such tralmng will permit prompt action when time is a critical factor. A sufficient number of personnel should be trained to ensure adequate coverage of J
I ah tasks at all times, if a dam is operated by remote control, training must include procedures for dis-I patching trained personnel to the site at any reported indication of distress.
j Personnel involved in inspections should be trained for the requirements of these duties;The training should cover the types of information needed to prepare for the inspections, critical features that should be observed, inspection techniques, and preparation of inspection reports.
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.' b. Academic Agency management should establish and maintain a program for continuing formal educatio training aimed at increasing and broadening the agency's base of professional expertise in areas relat safe design and construction of dams. Such training should provide for part and/or full time attendance universities and at special courses prepared by technical and professional organizations. Programs sho be designed to further the development of younger personnel and to provide refresher training or sab baticals for senior personnel.
Supmisory construction, inspection, and operation and maintenance staff should keep current on modern methods and techniques by attending technical courses. Pertinent courses are available from private sources and educationalinstitutions. Also, agencies that develop internal educational p this purpose should make them available to other agencies, permitting the agencies to gain mu in the exchange of information on new methods and practices.
- c. Professional .
i Professional growth of personnel should be encouraged by policies which ensure adequate training, '
support participation in technical and professional societies, and establish attractive career and p; tionalladders for technical specialists. Professional registration and active membership in professiona(
technical societies should be given due consideration in assessing qualificatlom for higher technical pI '
tions. i
- d. New Technology '
Provision should be made for the establishment of procedures to screen and disseminate information o technical advances relating to dam design, construction, and operation. Programs for continuing prof sional training should be oriented toward keeping the technical staff abreast of improved technology. ;
Interagency coordination on training in new technology should be established in areas of mutualinti
- 4. Communication P.ffective methods of communication, coordination, and review should be established and functio
- properly at all times, and be periodically reviewed and updated. Procedures for communication Federal, State, and local agencies on safety-relsted matters should be established. Specific are gested communication are discussed below.
- s. Interdisciplinary Direct and easily accessible means of communication should be established between personnelin ning, design, construction, and operations. Coordination is necessary for preparation of the si tion plan and for a common understanding of information needed for design. Prior to the site the design staff should arrange for meetings 'actween geologists, geotechnical engineers, and des review known site conditions, project functional requirements, and preliminary design concepts. A the site should be included in the review of existing information.
A document, referred to by some agencies as " Design Consideranons," should be prepared by design staff to transmit site specific design comiderations to the construction staff. This docu cover, but not be limited to, hydrologe and hydraulic considerations, geologic and geotechnical d foundation conditions, foundation treatment details, and anticipated foundation problems. It sho specify points at which inspection and approval are required by the design staff. Copies of the d should be furnished to those responsible for dam operation and inspection.
i Additionally, the design staff should arrange preconstruction orientation for the construction eng by the designers, geologists, and embankment and structural' engineers so that the constru and his staff fully understand the design concepts and the significance of the results of the explorat work. The construction engineers need to provide the designers, prior to advertisms the const:uction tract, comments on the constructibility, and the case of contract arf ministration for the plam a tions.
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13
During construction, the construction engineers should be alert for conditions that need to be reported to the design engineers. Field personnel should notify design personnel of any critical construction sequence or of a suspected change in conditions, that could affect the design of the structure. Design engineers with relevant expertise must be available to make regular visits to the construction site, and addi- i tional visits as needed when varying conditions are encountered. Changes in construction or materials I should be made only after plans for changes are approved by design personnel.
The design staff should furnish to the operation staff documents, referred to by some agencies as
" Operation and Maintenance Manuals," containing pertinent design and construction information on structures and equipment required for effective and safe operation of the dam. A conference of design and operating personnel should be held to ensure that the operators understand the operating and inspection procedures required for safe and reliable operation. Both the operators and the designers should have copies of equipment operating and testing manuals and procedures. The operators should notify the i I
designers of any safety related operating malfunctions and the actions taken to correct them. There should be continuing communication between operating and design staffs regarding plans and schedules for l periodic safety inspections of the dam. Copies of operation and maintenance manuals should be furnished i to the dam inspection staff. j l
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j b. Interagency i
l Interagency communications should be maintained on safety matters related to design, construction, and operation of dams, and related research. This should include exchange of materials such as design i standards, construction specifications, significant research reports, and final design and construction ]
f
' reports on major structures. The agencies should establish communications to periodically review investi-gation methods, construction materials testing standards, analytical methods, design philosophies, and management procedures, f S. Documentation )
I i
. Throughout project development (planning, site investigation, design, construction, initial reservoir till-ing, and operation), all data, computations, and engineering and management decisions should be Edocumented. Documentation should cover investigation and design, construction plans and construction history, operation and maintenance instructions and history, dama;;c and repairs and improvements, and
[
j periodic inspections during construction and' operation. It should inilude, but not be limited to, memo.
s runda, engineering reports, criteria, computations, drawings, and recovis of all major decisions pertaining
! to the safety of the dam.
I
- a. Desips Record Written documentation should be maintained in standardized format on all design-related information for the project. Planning design documentation should cover the project objectives and the studies made to locate, size, classify as to potential hazard, and select the type of dam and auxiliary facilities. Site investi-gation documentation should cover geologic mapping and studies made of the geologic and geotechnical explorations and conditions for the various dam sites considered and the detailed investigations for the chosen site. Geological, seismological, and geotechnical features and considerations, whether specifically l
identified during the investigation, interpretations from the data and experience at other sites, or suspected by experienced personnel, should be fully documented. Design documentation should include all design criteria, data and qualitative information, assumptions, analyses and computations, studies on discarded alternatives, and derived judgments and decisions.
As buih drawings should be prepared as facilities are completed, and should be made available to opera-tion and maintenance personnel and to the dam inspection staff.
l 1- b. Construction Record All phases of the construction should be documented, including reporting of routine and special activ-ities. Changes in construction plans and departures from expected site conditions should be documented.
-i with any consequent design changes. The record should include information on materials and construction processes, field exploration and test results, geologic mapping of foundations and excavations, inspection records, as-built drawings, and decisions to adapt the design to actual field conditions.
14
4 A formal plan for a construction inspection system should be developed, including inspection proce dures and types and forms of reports. The system should identify and record the status of inspec ,
approved and rejected materials. Survey notes, sketches, and records of all materials tests i control of construction quality should be maintained for the life of the project. A job diary should b maintained for each construction contract to provide a complete history of the work, listing in chron cal order the events having a bearing on performance of the work, and analysis of cause and effec special events. Photographic documentation of significant events, findings, and safety pro provided. The inspection program and record should give special attention to factors that may future influence on dam safety.
Documentation must also be provided as required by applicable procurement, safety and health, pers nel, and financial regulations,
- c. Initial Reservoir Filling and Surveillance Record An initial reservoir filling and surveillance plan should be prepared by the design staff, laitial fil should be well documented, including a record of reservoir elevations and controlled water relea the filling. The record should include complete written justification and design approval of any d from the planned filling. The surveillance record should include a!! information obtained from of the dam, appurtenant structures, abutments, and reservoir rim during the initial filling.
- d. Operation and Maintenance Record Operation and maintenance should bc fully documented, including the routine activities
' inspection processes, and complete information on project maintenance, rehabilitation, and menu. In addition to records on the actual operations, the operating record should include data on re voir fevels, inflow and outflow, drsinage system discharge and structural behavior, if there are maintenance problems that require continuing remedial work, a thorough record o should be maintained, and a final report rnade after complete remedy of the problem, f e. Permanent Files One copy of all documents concerning the project should be assembled 4n fha single projec j thould be kept up to date and should be maintained as a permanent archival reference. A seco materials should always be easily accessible to responsible personnel for reference in future r spections, and in dealing with problems, repairs, etc. Both f11es should be continuous records on problems, repairs, operation, instrumentation, and inspection for the life of the pr mation such as foundation reports and as-built drawings and maps should be permanently reta
)
j project and also at the agency's engineering design office.
.I.
- 6. Reviews
- a. Extent All factors affecting the safety of a dam during design, construction, and operation should on a systematic basis at appropriate levels of authority. Reviews include those internal those external to the agency by individuals or boards (consultanu) with recognized expertise ning, design, and construction.
- b. Internal
- Provision should be made for automatic internal review of all design decisions, methods, related to dam safety. Review should be at levels of authority above the design section or d supervisor relation. Uniformity of criteria and design technique should be maintained to ensure that specific experience is exchanged and used to advance the agency's ability to struct, and operate safe dams.
N Management technical personnel should review the construction periodically. Reviewin
{ should include geologists, geotechnical engineers, and embankment and/or ctructural en y ,
had experience in responsible positions relating to simihr structures. When appropria p include mechanical and/or electrical equipment engineers. Preconstruction insocction sh d
h 15 4
after geologic mapping is done and prior to ground surface disturbance. On large projects, construction reviews would normslly be at critical construction periods such as start and completion of foundation preparation and grouting, dam construction at several stages, and completion of the dam. Visits by appro-priate personnel are recommended every six months, and to accompany the consultants during scheduled reviews. The final construction inspection should cover inspection of completed structures and equipment, the adjacent valley floor and abutments, and the reservoir rim.
On smaller projects, the frequency of construction review and the disciplines represented in the resiew would vary with the size and complexity of the project. However, management should make certain that construction reviews are sufficient to cover the requirements for dam safety.
Reviews should be made of the agency's procedures for post-construction operation and perio lic inspec-tions. These would include the responsibilities for collection and evaluation of data from any dam instru-mentation.
Reviews should be made to ensure that the project emergency preparedness plan is periodically updated.
Formal documentation should be made of all significant findings from reviews and inspections.
I c. External I The need for review of a dam by independent experts (consultant board or firm) from outside the agency should be determined on a case-by-case basis, depending on the degree of hazard, size of the dam, com-plexity of the site geology and geotechnology, complexity of the design, or a specific need perceived by the i public. Consultant reviews should provide appropriate overview evaluations of site investigation, design, l -
and construction.
I
! Consultant 'eviews r of operation and maintenance practices, and of alterations and improvements
'should be conducted when the agency considers such reviews advisable.
The following text deals first with design and construction reviews. Applicab!c portions apply also to post-construction reviews; specifics for post-construction reviews are in the last paragraph of the section.
1 j The agency should be represented at each consultant meeting by appropriate design and construction staff. When appropriate, meetings should include a site visit. At each meeting the agency should formally document all aspects of the continued development of the project for presentation in a meeting-opening briefing to the consultants. The consultants should formally document findings and recommendations and present them at a closing conference with the agency staff, a
The consultant board members should be chosen to assure coverage of all areas of expertise needed to assess the dam design, construction, and safety. The board should contain at least three, but normally not more than five, permanent members. The board should always contain a general civil engineer, a geologist and/or geotechnical engineer, as appropriate a concrete and/or embankment dam engineer; and usually a
' member for the electrical and mechanical features, especially necessary if a power plant is part of the pro}-
ect. Additional specialists covering specific aspects such as structuralintegrity, earthquake response, or three-dimensional analysis should be assigned for short intervals as recommended by the board. The board should be formed during the design stage and consulted (if possible) on site selection, on type of structure, and for input to the feasibility study. The board should be kept active throughout design and construction, in order to keep the board completely familiar with all aspects of the project so they are in a position to re-spond rapidly if problems arise.
i
- During design and construction of large projects, the board should meet every 6 to 12 months, depend-mg upon activities and duration of the work. Meetings should be scheduled to review at specific phases of 3 construction. These phases might include, but not be limited to, review during the early stages of founda-p$ tion cicanup and treatment, on completion of foundation cleanup, and during the early stages of embank-3 16
ment and/or concrete placement. All board members should attend every meeting even though so meetings may not apply to all members. This would ensure that the entire board is fully aware o plete work status before being asked for their input on specific points, The briefing to the board by agency personnel at the start of a meeting should include exploratio structural adequacy and seepage characteristics of the foundation, proposeo f foundation treatmen grouting programs, quarry test data, test fill data, embankment requirements ti for zones a those zones, sources of materials, compaction requirements, inspection requirements, instrumenta on program, type of spillway (gated or ungated), proposed water release control systems, ments and care and diversion of water, power generation anticipated, and surge tank design. For c dams, the revievi would include concrete design and placement requirements in lieu of the em l Information.
On a smaller project, the use of consultants should be commensurate with the dam size and and with the degree of associated hazard. If there is significant hazard, the agency should o tant reviews adequate to assure independent assessment of the dam safety.
Consultants should be engaged during agency evaluations of existing dams if considered necessa provide independent support for agency assessment of dam safety. This might be in co studies for alterations or improvements for potential criticality of dam stability resulting from structure deterioration, or from increased reservoir levels due to possible flood inflows larger than desig j consequent inadequate spillway capacity. It might involve cons 4 clude consultation on the advisability and procedures for new materials investigations. Consultan l
features of existing dams may be individuals rather than formal boards.
- 7. Research and Development l A strong research and development effort is a necessary element in reducing the uncertaintie i sent tri dam design, hydrology and hydraulics, materials behavior, and construction techniques i
and practices. As part of their dam safety programs, agency m as the National Science Foundation and the U.S. Geological Survey.
1 b
)' a. Methods and Materials Management should ensure that a continuing review is made of state-of the art methods, ex research, etc., and that improvements are incorporated into agency criteria and methods of an ration, construction, testing, and instrumentation. The process should build from experience ects relating to constructibility, observed behavior, problems encountered, and problem so and their results. Experience histories should be reviewed, summarized, and disseminated to evalu rent practice in order to advance agency practices. Research and development needed on their use as revealed by dam observation and monitoring and new developments should be con continuing basis. Establishing a schedule of research priorities is necessary for overall rese
' development goals and for orderly and consistent progress in advancing dam technology.
- b. Risk Based Analysis The agencies should individually and cooperatively support research and development o l analysis and methodologies as related to the safety of dams. This research should be direc the fields of hydrology, earthquake hazard, and potential for dam failure. Existing agency work fields should be continued and expanded more specifically into developing risk concepts us evaluating safety issues. Existing work is exemplified by (1) the interagency research conf paragrapn c. oclow, (2) its adjunct meetings on hydraulles and earthquakes, and (3) risk evaluation for nuclear plants as applicable to radiological safety related dams.
' c. Interagency Coordination
' Existing interagency research coordination activities should be continued, with attention t unnecessary <iuplication. The biennial research coordination conference on water resources !
-i 17 ,
I Corps of Engineers, Bureau of Reclamation. Tennessee Valley Authority, and Bonneville Powtr Ad. '
ministration is an example of beneficial exchange needed on issues relating to dam safety.
- 8. Contracts
- a. Documents Agency procedures should ensure that all contracts for dam design, construction, and operation are written to accomplish the design intent and to require that contractors provide complete documentation of their work.
- b. Modifications During the construction period, any modifications in the design or construction which result from algnificant departures from expected field conditions, design reviews, or other studies should be promptly included in revisions to appropriate contracts. Such modifications, and any discovered later, that affect operation should be included in operation contracts (and in agency operation, monitoring, and maintenance policy). The basis and justification for any change should be documented.
- 9. Constraints Many constraints which are cutside agency authority can directly or indirectly affect dam safety.
Managers at alllevels must be continually aware of their fundamental responsibilities for dam safety and
- es ercise vigilance in identifying constraints on fulfilling those responsibilities. Every manager has a duty to seek resolution or mitigation of such constraints through his own agency channels or through interagency
' or intergovernmental channels as appropriate and available to him.
I I a. Funding for Organization Management Continuity and adequacy of funding are essential to carry out the various programs which ensure safe dams. The Zero Based Budget system offers an opportunity to managers to identify for high funding pr!ority those activities, programs, staff levels, and other operating requirements of a sound dam safety prograrn. Managers should avall themselves of this opportunity. Agencies should cooperatively develop common budgetary terms and conslatent processes to provide the necessary visibility of dam safety funding j essentials at all levels and within all branches of the government. Long term programming objectives
' should be established and adhered to, to meet the requirements of organization management, personnel
- staffing and training, research and development, quality construction and operation, a complete program j of inspection and evaluation of the safety of existing dams, and a planned program for the rehabilitation i and/or improvement of existing dams.
1 I b. Public Concerns Public individuals and groups should have the opportunity to voice their concerns in the d velopment of public works projects and during their operation. These concerns often represent constraints in the form of local or regional political interests, legislation, perceptions of risk and hazard, environmental factors, j, social conflicts, etc., which can influence technical decisions. Agencies should develop and organize their 3
procedures for early assimilation of ' hose public views which affect possible design, construction, or a
operating parameters and, in turn, influence dam safety. Resolution of public issues conflicts and prob-lems, including use of executive and legislative government decisions, should be made prior to the start of
}3 construction so that dam safety is not compromised.
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B. MANAGEMENT OF TECIINICAL ACTIVITIES - SITE -
INVESTIGATION AND DESIGN (SID)
This section of the guidelines outtmes the site investigation and designf technical activities th management should ensure are undertaken to obtain safe design of dams, it is recognized application of these guidelines will vary depending on the size and function of the dam.
1.11ydrology a, liazard Evaluation Arcu impacted by dam construction and existing dams should be examined for potential ha sent and future developments in the event of rnajor nooding by controlled Good dischar duced by dam failure or misoperation. This hazard evaluation is the basis for selection of th standards to be used in dam design or in evaluation of eahting dams.
- b. Flood Development Hypothetical Goods, generally of severe magnitude, should be developed for use of major dam and reservoir features, including development of appropriate floods for th period.
- c. I'lood Selection for Design (or Evaluation)
The selection of the design Good should be based on an evaluadon of the relative risks and co
, of flooding, under both present and future conditions 111gher risks may have to be accepted j isting structures because of irreconcilable conditions, l
When flooding.could cause significant har.ards to life or major property damage, the flood
~j design should have virturstly no chance ofditions being of exceeded without failure even when there is apparently no downstream hazard involved under present con development.
- d. !{ydrologic Design of Reservoir tu addition to se!cetion of a design Dood, the hydrologic design of a new reservoir or t an existing project involves consideration of discharse and storage capacities, reservoir cluding constraints, land requirements, and wind / wave effects. The evaluation of exis should include observed performance capabilities and whether improvements are necesary to e safety.
Reservoir regulation plans should be developed in the planning of projects d Whenso that realistic rele
' will be used in routing the design flood. Regulation plans should include the l construction perio gate operations are involved, a water control management plan should be established to d
' regulation in an effective and ef0cient manner. An emergency regulation plan is als the dam tender in the event of loss at communicadon with data in a timely and relitble manner.
The resetvoir regulation plans, water control management plan, and data information periodically reviewed for safety deficiencies and potential for misoperation during bo and normal conditions. Necessary corrections should be made as soon as practicable,
- e. Downstream Effects Safety design includes studies to ascertain areas that would be flooded during oc flood and in the event of dam failure. The aren downstream from the project should be 4
mine the need for land acquisition, flood plain managemen remaining risks of flooding.
y
- f. Warning Systems
', Safety design should include an emergency flood warning system and metion plan notify all concerned in ample time for appropriate action.
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- 2. Earthquake Investigation and Design
- a. Investigation Factors The following factors should be considered in selection of design earthquakes.
(1) Geologic and tectonic setting of the site area by analysis of the lithology, stratigraphy, structural geology, and tectonic history.
(2) llistorical earthquake record to include the size, location, and other seismological characteristics as available, and the relationship, if possible, with the tectorde siting of the area in which the carthquakes have occurred.
(3) Influence of the properties of the surficial materith on the determination of the size of historical earthquakes.
(4) Influence of faulting or other tectonic features on the estimate of the occurrence, size, and location of possible future earthquakes.
lj b. Selection of Design Earthquakes i From the above factors, earthquakes should be selected that have sufficient potential of occurring to re-i quire consideration tu the dam design. Earthquake description should include estimates to the extent prac.
I tical of the size, location, depth, focal mechanism, and frequency of occurrence.
i c. Engineering Seismology
- Determination should be made of the characteristics of ground motion that would be expected from the
- design earthquakes, to the extent possible, to include amplitude (displacement, velocity and acceleration),
frequency content, and duration.
j d. Need for Earthquake Analysis The probable effects of earthquakes on the dam and its appurtenant structures should be evaluated to i
- determine the need for inclusion of earthquake forces in the structures analyses. Evaluation includes con-sideration of factors such as the project stage, hazard and risk factors, the size of the dam and reservoir, the potential ground motion at the site, site geology, and type of structure. Where determination is made j that no earthquake forces are required in analysis, the determination should be justified.
- c. Seismic and Geologic Studies
( (1) Earthquake Sources. The essential nrst step is determination of the design seismic events (usually the maximum credible earthquakes) and an estimate of the ground motion at the site due to these evenu. From a study of the regional tectorucs and seismicity, and both regional and local geology, potential sources for seismic events are identified, and the maximum credible earthquake magnitudes postulated.
(2) Design Events. A maximum credible earthquake (MCE) is defined herein as the j hypothetical earthquake from a given source that could produce the severest vibratory ground motion at i the aam. Ttme histories of the estimated rock motion (accelerograms) at the dam for the various seismic events are selected to characterize the severity of the strong motions by their peak accelerations, frequency
} content, and duration.
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- f. Design for Earthquake Forces (1) Safety Concerns. All earthquake related safety concerns should be identified. Potential safety con: erns include but should not be limited to dam foundation integrity, stability, unacceptable stress levels, fault displacements; abutments stability; effects of dam overtoppingt dam stabilityt suscep-tibility of embankment dams to embankment or foundationliquefaction, cracking or excessive de rorma-g tion.
.' A survey of component and accessory structures and equipment should be made to identify those which have functions that are essential for earthquake-related safety.
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4 (2) Analysis Method. Determination of appropriate earthquake analysis methods for evalu tion of safety concerns may be, as appropriate, by qualitative evaluations, pseudostatic analysis dynamic analysis. The methods selected should be appropriate to the identified safety concern dance.with good engineering practice and with currently available technology.
Structural adequacy assessments should be mtde of all safety.
(3) Structural Adequacy.
related components and concerns identined. These assessments should incorporate all applicab analysis.
- 3. Geotechnics
- a. General (1) Site Specifics. Afler a site is selected, a program for the geotechnical exploration, desig and analysis of that specifle site is required. No checklist can be made which would cover all eve at all sites, or at any one site, and attempts to formulate such a list would be counterproductive to tent to ensure dam safety. The best insurance for adequate geotechnical work is a well trained and ex.
perienced staff actively involved in field inspections throughout all phases of the developme (2) Documentation. Because many evaluations are possible for a given set of geotech conditions, it is important that full documentation be made of the reasoning process involved In geotechnical decisions. General guidelines for documentation are given in section !!!.A.5.
(3) Management of Diverse Techtdcal Expertise. Geotechnical work encompasses the ex tise of geologists, geophysicists, and engineers-all with diverse experience, training, intere terminology. Thq administrative and technical supervision of these experts should be structured to timize coordination and cooperation. Management should encourage intellectual curiosity and an in quisitive approach to all geotechnical work. Since the field of geotechniques is rapidly expanding ment should assure that those associated with site exploration and development maintain currency I state of the art.
- b. Exploration, and Identification of Geotechnical Problems.
' The exploration program needs to be site specific, flexible, and executed so as to obtain t J
data from each part of the program. Agency management should ensure sufficient funding fo development of the exploration program in order to reduce uncertainties and to make ad for required corrective measures.
l The initial onsite exploration should in preceded by a review of all available information per
' development of the site (literature, maps, photographs, well and spring information, seis;nic d construction records, etc.). This should lead to the preparation of a detailed geological map of ing all available data. Geotechnical explorations generally proceed from wide spaced-geophysical surveys to determine the general geological conditions, to additional exp j an ongoing sequence to develop the geologic correlations and to determine the type of d site. The extent, depth, and type of exploration depend on the complexity of the geology and s of dam.
Generally, explorations are not complete at the end of the planning phase but continue d preparation of plans and specifications and into the constmetion phase. Conditions e construction often require additional explorations to evaluate the need for changes in the desig l All potential geological problems, inferred from onsite data and from experience at si be fully explored and described. This information should cover the types of adverse fea processes generally associated with a geological environment similar to that at the site i
the expected short. and long. term behavior of foundation and reservoir rim materials a l
jected to the changed geological environment associated with the construction and and to geologic processes operating during the life of the project.
During the course of the design and continued exploration of the project, all potential be investigated and corrected with appropriate treatment, or where uncertainty remains, de l
' 21 4
4 should be provided to conttol or monitor the problems. Types of problems which might require considera-tion include reservoir. induced seismicity, solubility, p pability and liquefaction potential of materials, foundation heave or deterioration during excavation, reservoir rim leakage and stability, past and future mining. and differential consolidation associated with petroleum or water extraction.
- c. Geotechnical Design Geotechnical design considerations for the dam foundation and reservoir area are essentially defined after the geologic conditions of the site, the type of dam, and the magnitude of the stresses imposed on the foundation by the dam and reservoir have been determined.
Foundation design typically consists of four distinct elements. These are (1) definition of the geometry of the foundations and areas of potentialinstability in the foundations, abutments, and slopes;(2) deter-mination of the properties of foundation materials using judgment, past experience, laboratory testing, and in situ testing; (3) an analytical procedure that predicts the behavior of the foundation in ..rms of stability, permeability and deformation; and (4) a reevaluation of parts (1) through (3) as construction pro-gresses so that a comparison can be made of preconstruction assumptions and conditions with the actual conditions revealed by the foundation excavation and treatment. Additional exploratory work may be re-quired. ..
- d. Foundation Treatment (1) General. The preparation of the foundation, including the abutments, is one of the most important phases of construction. The primary purposes of foundation treatment are to provide stability, obtain positive control of seepage, and minimize adverse deformation. The geology, foundation conds tions, fbundation treatment, and proposed structure should be considered together.
(2) Stability. Surfaces should be prepared to provide a satisfactory contact between the foun, dation and the overlying structure by removal of unsuitable materials. Deficiencies in the foundation which are not removed should either be treated by modification of the structure or by appropriate founda-tion treatment tailored to handle the conditions encountered.
(3) Positive Control of Scipsge. Highly permeable foundations should be treated by such measures as cutting off the pervious material, grouting, increasing the seepage path by upstream blankets, or controlling the seepage with drainage systems. Where appropriate, surficial cavities should be traced, cleaned out, and backfilled with material satisfying the design requirements. When cavities exist at depth, j measures should be taken to ensure against the migration of cavity filling material.
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(4) Control of piping. Silts and fine sands in the foundation, which are susceptible to piping, I should be removed if practical, cut off near the downstream limits of the dam, covered with impervious material, or provided with filtered drainage systems. If pipable materialis used in the dam, the foundation surface treatment should prevent migration of dam materialinto the foundation.
(5) Deformation. Foundations subject to differential settlement or foundations having highly compressible anomalies can cause stress concentrations or cracking in dams. The foundation excavation I should be shaped to remove abrupt changes in elevation to preclude excessive differential settlernent or j stress concentrations. Low shear strength matedal in a foundation can cause shear failure. Excavation and replacement of low strength material is a positive method for treating a foundation that has either or both 3
i of these unfavorable conditions, i
- e. Instrumentation Although a well conceived foundation instrumentation program serves to monitor the foundation and give an indication of distress, it cannot of itself certify the safety of the foundation. The expertise of the engineer / geologist to analyze and design and prepare a foundation that will safely carry the loads and water pressure imposed by the dam and the reservoir is fundamental to the design adequacy of the founda-tion. The purposes of foundation instrumentation are fourfold, to (1) provide data to validate design assumptions, (2) provide information on the continuing behavior of the foundation, (3) observe the perfor- I mance of critical known features, and (4) advance the state of the art of foundation engineering.
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t The genetal requirements for foundation instrumentation should be determined early in t project, and the rationale for the instrumentation should be the dam and reservoir, and the location of the project. Flexibility must be provided in the prog for changes from anticipated foundation conditions that are encountered during costruction a operations.
Intrinsic to an instrumentation program is the schedule for reading the instruments before and d construction, during initial reservoir fimng, and through the service life of the project. No less the r_ced for clear instructions for the prompt evaluation of data and prompt notification to re personnel when observatiom are atypical or diverge markedly from the design assumptions,
- f. Inspection and Continuing Evaluation During fhf d ti Constructionshould make omite evaluations
, Those responsible for the investigation and design o t e oun a on confirm that actual conditions conform to those assumed in the design and to review docu conditions.
A qualified project geologist should examine and map geologic details of the foundatio posed during construction. Investigation and testing at this point provide details usef grouting and other improvements and in confirrning the com expected to reveal unanticipated conditions which may require redesign or changes in foundation treatment.
} .ds Approval should be obtained from the geotechnical and design staffs before placement of on the foundation. This approval should be documented and should indicate that all unant tions encounteied were dealt with and that the foundation and its treatment meet the design r g.' Reevaluation at Existing Structures Older Federal dams may not have been designed to standards equal to current criteria. Al
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j tial portion of safety related dam incidents are associated j damt should be made.
These reevaluations should so beyond analysis of problems which are observed visua l strumentation data. A review should be made of all existing exploratory information, des J
construction records, and operation records, to determine the adequacy of the fotmdation w the present state of the art. Where available informatien is lasufficient or where defi suspected, modern criteria for analysis, instrumentation, the structure or foundation.
- 4. Hydraulic Appurtenances
- a. General (1) Protective Measure. All hydraulle appurtenances used for releasing water s designed to preclude jeopardy to the damming provisions.
(2) Blockage, Allowances for or preclusion of blockage of hydraulle facilities shou potated in the design.
(3) Reliability. When operational failure of a gated passage would jeopardire t provisions, alternate capacity should be provided. When operation of a gated pa reliable manpower, communications and accessibility should be assured.
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(4) Hydraulics and Hydrology. Hydraulle and hydrologic design considerations s correlated with section III.D.1.
- b. Design Rood Releases (1) Spillway and Outlets. Cated spillways are the usual hydraulic appurtenances for control of all or the rnajor portion of the design flood and major emergency releases. Outlets (sluiceways, conduits and tunnels) may be used alone or in conjunction with spillways to control flood discharges.
(a) Selectmn of type. Spillways and outlets should be selected to meet the site specific pur.
poses of the project. For a drainage area with short concentration time combined with reservoir storage capacity that is small relative to the flood volume, especially for embankment dams, (1) the spillway should usually be uncontrolled, and (2) outlets should not nonnally be used for sole or part control of the design flood except in special;ases where the outlets can be uncontrolled.
(b) Capacity. Spillway and outlet capacity should be sufficient to satisfy the discharge re-quirements of the reservoir regulation plan and other design considerations.
(2) Power Facilities. A portion of installed turbine flow capacity may be considered to assist in control of the design flood if it is demonstrated that possible power load interruptions during the design flood would not preclude operation of the power facilities.
c, Other Water Releases Other water release hydraulic appurtenances such as navigation facilities, locks, fish facilities, ice sluices, trash sluices, and water quality facilities should conform to the requirements of section 4.a.
- d. Reservoir Evacuation Where practicable, reservoir release facilities should be provided to lower the pool to a safe level ade-quate to correct conditions that might threaten the integrity of the dam.
- e. Control of Rows During Construction ne provisions of section 4.a also apply generally to the design of hydraulle appurtenances used during construction. The capacity of these appurtenances should be sufficient to satisfy the discharge re-quirements of the regulation plan for control of water during construction.,
- f. Design Criteria and Guidance (1) General, if existing design criteria and guidance from past projects and experience are used for design of the hydraulic appurtenances, their sufficiency should be documented.
l (2) }{ydraulic Model Tests. When sufficient criteria and guidance are not available for i analytical design of the hydraulic appurtenances, physical hydraulle model studies should be performed.
(3) Prototype Testing. Features of safety related hydraulle appurtenances that are beyond the state of the art, or for which model to prototype relationships have not been verifled, should be tested in
- the prototype.
i s. Reanalysis Because of Changes i Changes in project purpose, new purposes, operational requirements, limitations of constraints, design i criteria, or legal requirements may require that a reanalysis be made of the hydraulic appurtenances.
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- h. }{ydraulle Design involvement During 1.ife of Structure 11ydraulle design engineers should participate in the project periodic inspection program to evalu' ate the i operational adequacy of all hydraulic appurtenances essential to dam safety throughout the life of the
! structure including final disposition, l
. L Concrete Dams and Concrete Elements of Embankment Dams ,
I a. Site Specific Design i Because all dam sites are unique, the type of dam and its appurtenances should be specifically matched to site conditions, and project requirements. It is essential when reviewing the safety of existing dams to i u .
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consider conditions which may have changed physically and new concepts resulting frorn new tech or because of additional project information since corutruction, such u foundation deterioration, inc ed flood hydrographs, or larger design earthquakes.
- b. Materiah Concrete for the structures requires competent lavestigation of materials sources and adequacy of s ply testing of materials properties in accordance with accepted standards, and proper proport crete mixes (including additives) for strength, durability, control of thermal properties, and economy.
- c. Design of Structures There are three components of a dam which rJust be considered for safety; the foundation, the d its appurtenant structures.
(1) Foundation. Proper design of a concrete dam requires information on the foundation geological conditions and materials properties to assure its capability to support the loads of the d reservoir, in its natural state or as improved by foundation treatment.
(2) Dam. Concrete dams should be designed to be safe against i overturning d and sliding without exceeding allowable stresses of the foundation and the concrete for allloading conditions mpose on the dam. The shape and/or curvature of a dam and its contact b with i the foundation are extremely im tant in providing stability and favorable stress condidons. Proper consideration should e g ven to ensure the dam's safety in the event of overtopping.
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! Joints in the dam should be properly designed to control cracking due to thermal, shrinkage, and tural effects. Temperature control measures such as proper concrete mix design, precoollag of the con j
mix, and post. cooling of the concrete blocks can also be used to j on the behavior of the structure.
(3) Appurtenances. Safety relst'ed appiirtenances such as outlet works structures, spillwa i
j' and navigation locks should be designed wl:h the same degree of safety as the main dam. If the
- a powerhouse as an integral part of the dam, it should be designed for the same safety req dam.
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' d. Definition of Loads The dam and appurtenances should be designed for all static and dynamic loads to which they subjected. Dynamic loadings to be considered should include ine water.
- c. Design Methods The methods required for design of the several types of concrete darns and their appurtenances var from simple to complex, depending on the type and size of the structure, lil the hazard poten the kinds of loading, and foundation conditions, ne design process involves judgment and ana yt c expertise to select appropriate methods to analyze a structure whether it requires a sim analysis, and to determine design input data that is representa .
of the analysis ustd.
- f. Design Evaluation .
Technically quallfled supervisory personnel should assure that structures are designed to m requirements for safety. This includes confirmation of design i probability of the loading conditions.
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- g. Instrumentation Knowledge of the behavior of structures and their foundations may be gained by studying the service action of the structures using observations on embedded and other internal instrumentation and external measurements. Inf ormation from which a continuing assurance of the structural safety of the dam can be assessed is of primary importance, but information on structure behavict and the properties of dam and foundation materials serve to verify the design and to provide information for improvement of design.
Observations may be made in the dam and foundation in terms of strain, denection, pressure, temperature, stress, deformation, and drainage flows. External measurements for deflection and set.
tlements may be made by precise surveys on targets set on the dam, in galleries, in vertical wells in the dam, in tunnels, and on the foundation. Status reports on the condition of structures should be issued regularly.
Examinations of exhting structures should include assesstnents of whether additional instrumentation is required.
- h. Construction and Operational Followup it is necessary that the designers should be involved in the construction and operation processes to con-firm that the design intent is carried out, and to allow changes and modifications resulting from redesign necessitated by differences between design assurnptions and actual field or operating conditions.
- 6. Embankment Dams Section 5 contains general dam considerations; the following additional considerations are applicable to embankment dams.
- a. Site Specific Design Embankment design should be developed for specific site conditions and based on adequate exploration and testing to determine all pertinent geologic and material factors with particular emphasis on shear streng+h and stability, permeability and control of seepage, and consolidation and settlement.
Embankment dams are particularly vulnerable to damage and possible failure from internal erosion when founded on rock having large cavities, open joints, discontinuities, or other geologic defects. The sites should be carefully explored and special attention given to ilesign of cutoffs, foundation treatment, i
and other defensive measures. Special problems related to embankment integrity may include soft rock i such as clay shales, areal subsidence, old mining activity, solution-susceptible rock, and collapsing soils.
) b. hintedals
! Embankments can generally be designed to utilize locally available construction materials; investigation of materials characteristics is required and problem materials should be either discarded or protected by
- defensive design. There is often a need for importing special materials for slope protection, filters, and drainage systems. Any embankment zoning should consider the properties and quantities of available
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inaterials and the effect of their characteristics on the construction process.
! c. Design Constructibility Embankment designs should be constructible with regard to such items as location of borrow areas with l respect to flooding, in situ moisture conditions, climatic effects on construction schedules, width of zon-ing, and needs for special material processing. Design should include protection of critical features from overtopping by floods during construction.
- d. Embankment Design The safety of an embankment is dependent on its continued stability without excessive deformation
} under all conditions of environment and operation, and on control of seepage to pree!ude adverse effects
,} on stability and prevent migration of soil materials. Design considerations given below are specific to 1 cmbankment dams.
1 a
(1) Seismic. Where earthquake design is necessary, consideration should be given to earthquake-related concerns of soit liquefaction and cracking potential, stability and excessive deformation, abutment i stability, overtopping effects, and required defensive measures.
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' (2) Stability. Embankment stability should be analyzed for all pertinent st tic cnd dynamic loading conditions without exceeding ahowable shearing stresses in the embankment or foundation tors of safety should be appropriate to the probability of the loading conditions, and should consider effects of loading and time on shear strength, particularly if limited placement volume can result in construction. In most cases, embankments should be designed for unrestricted rates of reservolt fi drawdown.
(3) Settlement and Cracking. The potential for transverse cracking of the embankment ca by differential settlement, tension zones, and possible hydraulic fracturing should be minim consideration of abutments, foundation and cutoff trenchen and their geometry and treatment. Filte zones of adequate size should be positioned upstream and downttream of the impervious zone at a tions where there is a possibility of transverse cracking regardless of cause. Potential problems of diff tial settlement should be considered in establishing the construction sequence.
(4) Seepage. The design should attempt to prevent or mirdmlze seepage through the emban ment and its foundation and abutments; however, the designer should recognize that seepage usual occurs and that protective control measures must be provided. Filtering transition zones and founda and abutment treatment to seal openings should be provided wherever necessary to preclude migra soll materials into or out of all embankment element contacts both upstream and downstream. Filters drainage blankets, and transitions should be of a quality and size to conservatively control and s discharge seepage for all conditions for the life of the project. Particular attention should be given to tacts with foundation, abutments, embedded structures, and the end slope of closure sections to ensure i adequate compaction and bonding to control seepage.
4 (5) Zorting. Embankment zoning when used should ensure adequate stability for all pertin conditions, and should control seepage through the embankment and provide filter action to prevent migration of material.
(6) Erosion. Upstream and downstream slopes and foundation and abutment contacts be protected against erosion from surface runoff, wave action, and impinging currents. Spi outlet works should be located and designed so that discharges do not crode the embankment or its 1 dation.
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- c. Instrumentation Embankment design and predidion of embankment performance are based on an imprecise com
.tlon of theory and empirical procedure; consequently performance during construction and ope should be monitored by a designed system of external measurements and/or installed instrumentat well planned system of instruments, when appropriate, should be installed to provide data i external movements and on water pressures at criticallocations in the embankment and foundatio both construction and operation.
- f. Construction and Operational Followup In addition to the need for designers to be involved in construction and operation of dams in ge i
confirm the design intent and assess the need for possible design changes, certain other requireme should be observed at embankment dams. Stability should be evaluated during and after constru using strength parameters from as placed materials and observations of pore pressure and when conditions warrant. Designers should inspect and review performance of embankments du after reservoir impoundment to detect and provide prompt remedial treatment for problems. Whi emphasis is placed on initialimpoundment, the surveillance should continue for the life of the the state of the art advat ces in analysis, material behavior, and methods of observation, deficie embankments may be suspected or becorne obvious and should be investigated and correcte experience information should be summarized and used to further advance the state of the art.
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C. . MANAGEMENT OF TECIINICA.L ACTIVITIES -
CONSTRUCTION (CON)
- 1. Introduction This section of the guidelines outlines the construction technical activities that agency management should ensure are undertaken to obtain safe construction of dams. The principles and guidelines are prepared in a broad sense to ensure that construction of a safe structure is the prime requisite,
- a. Construction Contracts Construction contracts should be based on site conditions as interpreted at the time of contract award.
All anticipated work on foundation cleanup, preparation, and treatment should be included as specified items of the work. Contract provisions should require the contractor to submit to the construction engineer advance notice of significant shift change, to enable adequate inspection coverage of multishift operations,
- b. Construction / Design Interface Many aspects of construction directly overlap in design considerations. Reference is made below to numbered paragraphs in Section !!!.II, Management of Technical Activities - Site Investigation and Design, which concern such common interests:
- 3. Geotechnics
- a. General (1) Site Specifics
- b. Exploration, and identification of Geotechnical Problems '
- c. Geotechnical Design i d. Foundation Treatment
- e. Instrumentation
- f. Inspection and Continuing Evaluation During Construction
- 4. Hydraulic Appurtenances
- c. Control of Flows Durins Construction
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- 5. Concrete Dams and Concrete Elements of Embankment Dams
, a. Site Specific Design
- b. Materials -
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- c. Design of Structures ,
j (1) Foundation ,
- g. Instrumentation
- h. Construction and Operational Followup
- 6. Embankment Dams
- a. Site Specific Design
- b. Materials 1 c. Design Constructibility
- d. Embankment Design (3) Settlement and Cracking
-) (4) Seepage a e. Instrumentation
- f. Construction and Operational Followup
- 2. Evaluation During Construction
- Field personnel must be highly trained and experienced if the design principles and site conditions are to 1 be undentood end a safe structure is to be constructed.
Wifen differing site conditions (different from those anthipated) are encountered, construction super-visory forces must have authority to suspend any or all portions of the work affected until the design engineen, with assistance as needed, can evaluate the condition and determine if design modification is required.
Construedon tallestones should be identified when the design engineen willinspect the work and concur with the progress of construction. .
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- 3. Orientation of Construction Engineers and Ficid Inspectors Construction engineers need to be aware of design philosophies and assumptions as to site con and function of project structures, and must understand the designers' intent concerning specia provisions in the specifications. Identified preconstruction activities should include the orien '
atruction engineers to the site specificity of the design and to the close communication requirem all concerned engineering dlwiplines during the construction process. For major projects, there s periodic meetings between design and construction enginests to discuss upcoming const Also, during the initial stages of important construction activitie
- design requirements.
Construction specifications, supplemental reports, and conferences to orient ble, field persennel to the p ticular site, the features of the dam, and the designers' intent for construction should, as applica include the following:
- a. Design Related (1) Design concepts. Explanation of philosophies and assumptions and the reasons f requirements in the specifications to assure accomplishment of design intent.
(2) Construction sequence. Identification and explanation of the dates to which construct progress must conform to satisfy project requirements, and the special sequences for that are required by design.
(3) Instrumentation systems. Description of the instrument types, their purpose, the pro-l cedures for installation of each instrument type, the method and time interval for reading each last l' and the importance of prompt data transmission for analysis and feedback.
(4) Care and diversion of water. Description of the design features included to prevent control flooding and turbidity and accomplish diversion and closurei ofi the dam.This should a f
the design requirements for controlling normal flows through the
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- problems should be emphasized.
- b. Foundation g (1) Description. Discussion of the type of foundation conditions expected to exist, i.e., over burden, general rock description, formation weaknesses such as joints, shears and faults, a
) foundation conditions.
S (2) Excavation, Discussion of the depth and nature of materials expected to be encou the controls for dewatering and blasting, identification of critical areas, quantity estimates, and an able foundation.
(3) Preparation. Review of the methods of rock foundation preparations such as: clea use of wire mesh, mortar, shoterete, or rock bolts; grouting, and treatment of faults, shears an well as subsequent exploration to assure desired results. Review of methods of earth foundation p
[ tion.
- c. Materit ts (1) Materials from required excavation. Definition of acceptable and unacceptable pr of materials, the usage and the processing requirements if used, and identification of waste (2) Other excavated materials. Identification of the location and amount of usable m
" based on current test data," available from all designated areas, including borrow pits. Re blasting methods that are expected to produce the desired rock quality and sizes. Discussi pected amounts of waste and the areas where borderline material may be used in l berms or certain zones of the downstream shell of an earthfill dam. .
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(3) Embankment. Description of both acceptable and unacceptable material properties, place-ment, and compaction procedures for each zone. Review of required procedures for areas adjacent to abutments, around instruments, and at interfaces between zones and/or structures.
(4) Concrete and concrete materials. Identification of acceptable aggregate sources and review of mix designs, joint and surface treatment, finish requirements, form tolerances, and placement pro-cedures. Cooling as well as hot and cold weather protection requirements should be defined.
- d. Construction General (1) Field control. Discussion of the quality assurance procedures required to control all phases of construction. Acceptable placement standards should be established for concrete, earth and rock materials, and embankments. .
(2) Structural. Discussion of structural steel installation, reinforcing steel placement, and :tntic.
ipated problem areas and specified treatment for such areas.
(3) Mechanical-electrical. Description of equipment installation requirements, special proce.
dures, performance tests, protective coatings, and protection devices such as ground fault indicators.
(4) Environmental. Identification of those construction controla required to minimize environ-mental damage, comply with environmental regulations, and assure public involvement.
- 4. Construction Assurance
- a. Construction Procedures. Agency criteria must casure that acceptable methods and procedures are specified and utilized to accomplish design requirements. At the same time, the design and construction organizations must maintain the Dexibility necessary to modify design, material requirements, and con-struction specifications as conditions dictate without altering the basic design intent.
- b. Construction Materials Testing. A materials laboratory must be established at the field con.
struction office that is adequately staffed and equipped to accomplish the on site testing requirements set forth in the engineering considerations and instructions to field inspection personnel. Provisions should be !
made for a thorough and periodic reviewI'above project level" of the construction materials testing pro-cedures to assure their. continued suitability. Periodic companion test samples of embankment material should be checked by h!gher echelon for uniform test assurance. ;
- c. Quality Assurance. It is mandatory that adequate construction quality assurance systems and
' ' procedures be established to assure safe dam construction. The quality assurance system must guarantee, by direct inspection and testing, that construction is accomplished in compliance with the contract plans and specifications. The quality assurance system must identify when site conditions require modification
.; of the design to ensure construction of a safe dam and must docurnent the construction aethities and test results. Daily inspector's reports, laboratory test data records, and photographs are the minimum man.
datory methods of documentation. General guidelines for documentation are given in section III.A.$.
l t As a part of the quality assurance program the contractor should normally be required to submit various l
plans for approval not limited to, but including, the following:
Construction Schedule Safety Program l, Care and Diversion of Water (including pollution control) l - Fire Protection l ,
Plant Layout (including haulroads) l Environmental Measures Equipment Inventory Dewatering Foundations and Borrow Areas
- Excavation Sequence of Foundations and Borrow Areas Drilling and Blasting Procedures ,
4 Concrete Placement Restoration of Construction Area ,
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D. MANAGEMENT OF TECHNICAL ACTIVITIES -
OPERATION AND MAINTENANCE (OPM)
This section of the guidelines outlines the technical activities for operation and maintenance, periodic i spection program, and emergency action planning that agency management should ensure are u to obtain safe operation of dams.
- 1. Operation and Maintenance
- a. General The intent is to define practices which will ensure safe operation of dams and reservoirs and to require maintenance program that will provide timely repair of facilities. It is assutned that each Federal age responsible for proper operation and maintenance of dams that are owned by the agency or tha its' jurisdiction.
Operation and maintenance personnel should be selected on the basis of their capability to a 3
knowledge needed to perform the many functions of operation and maintenance, and should be tr the associated duties at each specific project.
I All operation and maintenance manuals should be kept current, and records should be main Instructions, inspections and equipment testing, with copies to those responsible for design and dam inspections. General guidelines for documentation are given in section lif.A.$.
I lo the following sections, oudets or outlet gates refer to gates or valves on any outlets such as slulces conduits or tunnels, pumps, generating units, and Infrequently operated plant intake and discharge gates, if the project has a navigation lock, emergency closure and other infrequently operated equipmen included. .
- b. Operating Procedures .
1 Written operating instructions should be prepared for the dam arid its associated structures and ment. The instructions should cover the functions'of the dam and reservoir and dueribe procedures follow during flood conditions to ensure dam safety.
Reservoir operating rule curves should be available for each normal mode of operation and for emer gency conditions, An auxiliary power system, such as a gasoline or diesel operated generator, is essential if the o i spillway gates and other dam facilities are electrically operated, i
All spillway and outlet gates should be tested on a regular schedule. The tests should includ the primary and the auxiliary power systems.
Project security is a matter of concern at all major dams. This includes preventing structural vandals or saboteurs and unauthorized operation of outlet or spillway gates. In most cases restric public access is essendal, and in some instances armed guards may be necessary.
Public safety is of paramount importance at all dams and reservoirs. Specificall/, public safety o
[ reservoir, in areas adjacent to the reservoir, and below the dam should be considered, particu recreational areas. Safety measures should include identification of high watermarks to indicate past or prob;ble reservoir levels and streamflows, posting of safety instructions at highly visible an and providing audible safety warnings upstream of and below outlets as appropriate.
Communication should be maintained among affected governmental bodies and with the public to enhance the safety aspects of the operation of the dam. Communication alternatives include written munications, radio, telephone, television, and newspapers.
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- c. Maintenance Procedures
- Written instructions should provide information needed for proper maintenance of all water control facilities.
Specialists should prepare maintenance checklists indicating the maintenance procedures and protective measures for each structure and for each piece of operating, communications, and power equipment,in-cluding existing monitoring systems. Special attention should be given to known problem areas.
Special instructions should be provided for checking operating facilities following floods, earthquakes, tornados, and other natural phenomena.
Maintenance procedures include preventive measures such as painting and lubrication as well as repairs to keep equipment in intended operating condition, and minor structural repairs such as maintain-ing drainage systems and correcting minor deterioration of concrete and embankment surfaces. The design staff should be apprised of any significant maintent.nce work.
- 2. Periodic Inspection Program a, General The purpose of a periodic inspection program is to verify throughout the operating life of the project the structuralintegrity of the dam and appurtenant structures, assuring protection of human life and property.
Periodic inspections disclose conditions which might disrupt operation or threaten dam safety, in tirne for them to be corrected. When such conditions are encountered, it is necessary to determine the adequacy of struerures and facilities to continue serving the purposes for which they were designed, and to identify the extent of' deterioration as a basis for planning malt.tenance, repair or rehabilitation.
The following general principles and guidelines for a periodic inspection program should be used by Federal agencies responsible for operation or regulation of dams.
All existing dams with a significant hazard potential should have a safety evaluation based on current technical guidelines and criteria. New rinns added to the inspection program should be planned, designed, and constructed in accordance with current technical criteria. Impiovements in dam technology require that dams and appurtenant structures be reassessed to assure dam safety for more stringent design and
, materials criteria. .
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- Periodic inspection of dams, reservoirs, and appurtenant structures involves important aspects other than dam safety; however, these guidelines encompass only dam sa fety issues. Each agency is responsible j
1 for assuring that the existing dams for which it is responsible are periodically inspected, and that new dams are inspected initially upon completion of construction and periodically thereafter.
- b. Types and Frequencies of Inspections j ne inspection types and intervals herein recommended are for general guidance in developing inspec-d tion programs for all Federal dams. These guidelines do not preclude other inspections or more frequent
) inspections if deemed necessary depending on project history and importance of the facility. For some projects less frequent inspections may be permissible where hazard potential and structuralintegrity war-rant such relaxation.
To maintain control of the inspection program, a formal inspection schedule should be maintained which lists each feature to be inspected, frequency of inspection, date last inspected, date of last inspection report, maintenance record, description of repairs made, and date of next inspection. The schedule should also have a note on major alterations that are made.
. Inspection personnel should be selected carefully, have qualifications commensurate with their assigned
.J levels of responsibility, and receive training in the inspection procedures. Qualifications and training re-quired for inspection personnel may vary with the complexity of the facility and with the level of inspec-3' tion. )
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4 b
- (1) Inf ormal Inspections. The purpose of informal b vationsinspections of the is to have as a continuous surveillance of the dam. Employees at the project are to make frequent o ser l dam and appurtenances and of operation and maintenance. dThey are tc idenMfy ditions in accordance with adequate instructions and guidance. j by engineer-A detailed checklist o may be provided. The instructions or checklists should be prepared i d and specifically for the pr it of Ins and operating specialists. The personnel ii l dangerous should beperforming the ibility.
their carefulinspection and reporting. Any unusual conditions th Particular attention should be given to detecting evidence of (or changes in) lea boils, seepage, slope Instability, undue settlement, displacement, tilting, crack proper functioning of drains and relief wells.
(a) Frequency of informalinspections. Informali inspections l for loss of should be sche perienced, trained engineers as needed according to the dam be responsive to observed changing conditions.
Operating personnel should make an inspection immediately aher any unu floods, earthquakes, suspected sabotage, or vandalism.
(b) Qualifications of personnel for informal irupections. Informal inspections i instances can be performed satisfactorily by dam tenders or operation and maint formally educated in the field of engineering or geology. Persons selected to ma however, must have sufficient training and experience to allow have anthem to recognize i
j must have demonstrated their ability hto they perform understand operation tions on performance of responsibilities and must be evaluatedi iperiodically g structural to assure t at the requirements and are capable of performing them. In addition, d reporting procedures ab- fer mon tor n performance, observing the structure, its foundation, abutments, and appurtenances, an
' normal conditions must be clearly defined and un'deistood by these personnel.
! s i hould include a thorough field in-
'(2) Intermediate Inspections. Intermediate inspect ons s d t d l
j spection of the dam and appurtentait structures, and a rev d by specialists.
4 these inspectors, arrangements should be made for inspections to be conducte (a) Frequency of intermediate inspections. Intermediate inspections should
{ formed preferably on an annual basis, but at least bienn
} sible enginects on the basis of the dam's size, importance, and potential for damage to l
(b) Qualifications of personnel for intermediate inspections. f Intermediate should be performed by technically qualified i f the dam andengineers, e i fhdm 4
with all pertinent documentation, especially the operation and The dam tender o operator should be a participant in these inspections.
(3', Formal and Special inspections. A formal inspection d i w to is required perio l
, safety and in'egrity of the dam and appunenant d to structures clude r review of all pertinent documents including instrumentation, ki the detailedin- operation, and ma t res
- the degree necessary, documentation on investigation, de 33 +
- 4 . - - - _ . _ . _ . _ _ _ _ _
r affecting the integrity of the dam should be included. All formal inspections should be conducted by a '
team of highly trained specialists. To assure that a dam and its appurtenant facilities are thoroughly in-spected, checklists should be prepared to cover the condition of structural, electrical, and mechanical features. This inspection should also verify that operating instructions are available and understood, in-strumentatlon is adequate and data is assessed to assure structures are performing as designed, and there are emergency provisions for access to and communication with all project operating facilities.
(a) Frequency of formalinspections. Formalinspections should be made periodically at intervals not to exceed 3 years. Depending on past experience or the project history, sorne dams may re-quire more frequent formalinspections.
(b) Frequency of special inspections. Special inspections should be performed immedi-ately after the dam has passed unusually large floods and after the occurrence of significant carthquakes, i sabotage, or other unusual events reported by operating personnel. )
l (c) Qualifications of personnel for formal and special inspections. Formal and special inspections should be conducted under the direction of licensed professional engineers experienced in the investigation, design, construction, and operation of dams. The inspection team should be . chosen on a ;
site specific basis considering the nature and type of the dam. The inspection team should comprise in-dividuals having appropriate specialized knowledge in structural, mechanical, electrical, hydraulle, and embankment design; geology; concrete materials; and construction procedures. They must be capable of interpreting structural performance and relating conditions found to current criteria and safety aspects. It is imperative that the inspection team adequately prepare for the inspections by reviewing and discussing all documents relative to the safety of the dam,
- c. Instrumentation Instrumentation or performance observation devices are used to supplement visual inspections in evaluating the performance and safety of dams Careful examination of instrumentation data on a con.
tinuing basis may reveal a possible critical condition. Conversely, instrumentation may be a means of assuring that an observed condition is not serious and does not require immediate remedini measures.
(1) Adequacy of Instrumentation. InstrumentAtlon 16 monito(structural and functional per-i formance should be installed in dams where complex or unusual site conditions have been encountered or i where there is a high probabliity that failure could result in loss of life or extensive property damage. In-i struments should be examined periodically for proper functioning. The adequacy of the installed in-
! strumentation should be assessed from time to time by specialists to determine if it is sufficient to help I evaluate the performance of the dam. When required, additional instrumentation should be installed to conntm suspicious trends or to explore an indicated potential adverse trend.
, (2) Observation of Monitodng Devices. The instrumentation data should be collected by per-sonnel trained specifically for the purpose, including training to recognh.e and immediately report to those responsible for inspections any anomalies in the readings or measurements. Performance observation data should be properly tabulated for record purposes.
}
(a) Frequency of observations. The frequency of instrument readings should be estab-lished at the time the instrumentation system is designed in order to give a timely warning of possible adverse conditions. Whenever necessary, more frequent readings, sometimes as often as hourly, should be taken to monitor a suspected rapidly changing adverse condition. The frequency or number of readings may be reduced after the project has been in operation for an extended time and performance observation data indicates that readings have stabilired.
(3) Data Analysis. It is essential that instrumentation data be processed, reviewed and as-sessed in a timely manner by specialists familiar with the design, constniction, and operation of the proj-ect. Operation manuals and design information should be referred to in the evaluation of possible adverse trends. The performance observation data should be periodically analyzed to determine whether project i structures are reacting as assumed in the design, and to detect behavior conditions that may indicate the a need for corrective action.
N 4
1
- d. Correction of Deficiences The inspection program could reveal those deficiencies or h potential i denciencies wh could eventually lead to failure of the dam. Deficiencies may vary b do from emergency type item I
mediate action is required, to nonemergency type items whichd bemust made be corrected in a timely f il h -
not present an immediate danger to the safety i of the structure already occurred or is imrninent are discussed in Section Ill.D.3, Emergency Action Plann ng.
(1) liigh Priority Corrective Action. High priority corrective h ld have action is required for def cies which could result in failure of the dam within a short period of time. i Heads of agencies authorities, procedures and levels of delegation for transfer ofi funds ill and other emergenc sions to ensure they are adequate for accomplishing corrective hi actions in cases where tim not permit allocation through the normal budget process. Procedures for seeking trans beyond that delegated to the agency and/or requests for s tion to enabk expeditious action by the President and/or the Congress.
(2) Nonemergency Corrective Action. Nonemergency h life or property corrective action is action t there is no immediate threat to the safety or operation of the dam, nor any t reat to downstream. "The corrective action should h ' hbe scheduled in special reservoir operations when required. Some of these deficiencies may be corre regular operation and maintenance program discussed in Section Ill.D.1, Operation I (3) Follow.up Action. Periodic inspection reports should i continue i to list previous tifled deficiencies along with any newly discovered deficiencies and show the status of corre
/
Appropriate inspection personnel should make frequent field blexaminations as long l
i see that all corrective measures are being completed. When*
ment personnel should be notified of the findings.
- e. Documentation ,
Proper documentation of the dam's current condition and past d performance is n
- adequacy of operation, maintenance, surveillance, l t data and pro t
tions, modifications, repair, and remedial work should be esta with the initial site investigation for the dam and continue through the life of the structure.
(1) Instrumentation. Allinstrumentation observation i data and e properly tabulated and documented for record purposes. i Maintenance of instrumen A complete history l
that details of the installation be available for a clear understan tion of current instrumentation data.
(2) Inspections. Allinspection observations, especially as di related to the safety 4
should be documented. The extent and nature hich describe condi- of inspectio the nudings, informalinspection reports may range from memoranda to supervisors w diate inspection tions and corrective actions, to detailed accounts of an event or occurrence. il Interme reports may vary from similar memoranda or trip reports to more hi l formal reports co records, detail, and recommendations. Formal and spec J
poses in order to form a basis for major remedial work when required.
should carefully document times of inspections, inspecti 35 4
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-- ~ - - - - _ ~ _ _ _ _ _ _
(3) Correction of Deficiencies. All deficiencies corrected as a result of the recommendationi contained in periodic inspection reports should be fully documented in report form and made a part of the permanent project record. Alterations made to the facility as a result of changes in criteria to meet current practices or changes in dam technology should be fully documented, including as-constructed drawings.
- 1. Emergency Action Plantdng
- a. C;neral it is intended that the guidelines for the design, construction, operation and maintenance, l and inspection of dams will minimize the risk of future dam fanures. Nevertheless, it is recognized that j despite the adequacy of those guidelines and their implementation, the possibility of dam fauures still ex. 1 ists. Even.though the probability of such fgilures is small, prrplanmng is required to identify conditions j which could lead to failure, in order to initiate emergency mes utes to prevent such failures as a first priori- i ty, and, if this is not possible, to minimize the extent and ef'ects of such fauure. These guidelines provide )
operating and mobilization procedures to be followed uprn indication of an impending or possible dam ;
faDure or a major Good. i Each Federal agency which owns or is responsible for dams ard each public or private owner of a Federally regulated dam (hereinafter, dam agency or owner) should evaluate the possible mode:
of failure of each dam, indicators or precursors of failure for each mode, possible emergency actions ap-propriate for each mode, and the effects on downstream areas of failure by each mode. In every case the evaluation should recognize the possibility of sudden failure, and should provide a basis for such " worst case"' emergency planning actions in terms of notification and evacuation procedures where failure would pose a significant danger to human life and property. Plans should then be prepared in a degree of detail commensurate with the hazard, and instructions provided to operators and attendants regarding the ac.
tions to be taken in an emergency. Planning should be coorenated with local officials, as necessary, to enable those officials to draw up a workable plan for notifying and evacuating local communities when conditions affecting dam safety arise.
- b. Evaluation of Emergency Potential Prior to development of an emergency action plan, consideration must be given to the extent of land areas, and types of development with the areas, that would be inundated as a result of dam failure or flood, and the time available for emergency response.
(1) Determination of Mode of Dam Failure. There are many potential causes and modes of 3 dam failure, depending upon the type of structure and its foundation characteristics. Similarly, there are degrees of " failure" and often, progressive stages of failure. Many dam failures can be prevented from reaching a final catastrophic stage by recognition of early indicators or precursor conditions, and by prompt, effective emergency actions. While emergency planning should emphasize preventive actions, recognition must be given to the catastrophic condition, and hazard potential be evaluated in the light.
Analysis should be made to determine the most likely mode of dam failure under the most adverse condi-tion and the resulting peak water outflow following the failure. Where there is a Sr.,es of dams on the stream, analyses should include consideration of the potential for progressive " domino" failure of the dams.
(2) Inundation Maps. To evaluate the effects of dam failure, maps should be prepared delineating the area which would be inundated in the event of failure. Land uses and significant develop-
-i ment or improvements within the area of inundation should be indicated. The maps should be equivalent to or more detailed than the Urdted States Geological Survey (USGS) quadrangle maps,71/2-minute
}
series, or of sufficient scale and detan to identify clearly the area that should be evacuated if there is I evident danger of failure of the dam. Copies of the maps should be distributed to local government of.
1 ficiais for use in the development of an evacuation plan.
(3) Classification of Inundation Areas. To assist in the evaluation of hazard potential, areas delineated on inundation maps should be classified in accordance with the degree of occupancy and hazard potential. *Ihe potential for loss of life is affected by many factors, including but not limited to the capacity and number of exit roads to higher ground and available transportation. Hazard potential is greatest in
'j 36 ,
I. -
l
' urban areas. Since the extent of Inundation is usually difficult to delineate precisely be map limitations, the evaluation of hazard potential should be conservative.
The hazard potential for affected recreation areas varies greatly, depending on the typ ,
fered, intensity of use, communication facilities, and available transportation. The poten I may be increased where recreationists are widely scattered over the area of potentia would be difficult to locate on short notice.
Many industries and utilitiec requiring substantial quantitles of water for one or more s manuf acture of products or generation of power are located on or near rivers or streams areas and industries can, in addition to causing the potential for loss of life, damage to ma manufactured products, raw materials and materials in process of manufacture,1,nterrupt munity services.
Rural areas usually have the least hazard potential. Ilowever, the potential for loss of damage to large areas of intensely cultivated agriculturalland can cause high economic loss (4) Time Available for Response. Analyses should be made to evaluate the stru dation, and other characteristics of the dam and determine those conditions which cou result in slow, rapid or practically instantaneous dam failure.
- c. Actions to Prevent Failure or Minimize Effects of Failure (1) Development of Emergency Action Plan. An emergency action plan should for each dam that constitutes a hazard to life and property, incorporating preplanned emergen to be taken prior to and following assumed dam failure. De plan should be coordinated w
- mental and other authorities involved in public safety and be approved by appropriate top owner management. To the extent possible, the emergency action plan should define em tha.1 require immediate notification of local officials. The emergency action plan shou tion plans, which are discussed in section (2) below.
Emergency scenarios should be prepared for possible modes of failure for each dam scenarios should be used to test the readiness capabilities of project staff.and logistics.
A procedure should be established for review and revision, as necessary, of the e including notification plans and evacuation plans, at least once every 2 years. Such revi dinated among all organizations responsible for preparation and execution of the plans.
(2) Notification Plans. Plans for notification of key personnel and the public are part of the emergency action plan and should be prepare addresses, office and ho ne telephone numbers, and radio communication frequencie available, for agency or owner personnel, public officials, and other personnel and al be notified as soon as emergency situations develop.' A procedure should be developed rent.
Each type of notification plan should contain the order in which key agency or owner s sonnel or alternates should be notified. At least one key supervisory level or job posit designated to be manned or the responsible person should be immediately availa 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> a day. A copy of each notification plan must be posted in a prominent place a near a telephone and/or radio transmitter. All project personnel should be familiar w i
procedures each is to follow in the event of an emergency. Copies of the notific available at the home and the office of each person involved.
Where dams located upstream from the dam for which the plan is being prepared cou reduce inflow or where the operation of downstream dams would be affected by failu operators of those dams should be kept informed of the curTent and expected c information becomes available.
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. _ . _ _ . -- _________m _ _ _ _ _ . _ .. _ _ _ . _ . _____ __._._
Civil defense officials having jurisdiction over all or part of the area subject to inundation should receive early notification. Local law enforcement officials and, when possible, local government officials and
. public safety officials should receive early notification.
The capabilities of the Defense Civil Preparedness, Agency's National Warning System (NAWAS) should be determined for the project and utilized as appropriate. Information can be obtained from State of local civil defense organizations.
Potentially affected industries downstream should be kept informed so that actions to reduce risk of life and economic loss can be taken. Coordination with local government and civil defense officials would determine responsibility for the notification. Normally, this would be a local government responsibility.
When it is determined that a dam may be in danger of falling, the public officials responsible for the decision to implement the evacuation plan should be kept informed of the developing emergency conditions.
The news media, including radio, television, and newspapers, should be utilized to the extent available and appropriate. Notification plans should define emergency situations for which each medium will be utilized and should include an example of a news release that would be the most effective for each possible emergency. Use of news media should be preplanned insofar as is possible by agency and owner personnel and the State and/or local government. Information should be written in clear, concise language. Releases to news media should not be relied upon as the primary means of notification.
Notification of recreation users is frequently diffleult because the individuals are often alone and away from any means of ready communication. Comideration should be given to the use of standard emergency warning devices such as sirens at the damsite. Consideration should be given to the use of helicopters with i bullhorns for areas further downstream. Vehicles equipped with public address systems and helicopters I with bullhorns are capable of covering large areas effectively.
s Telephonic communication should not be solely relied on in critical situations. A backup radio com.
munication system should be provided and tested at least once every 3 months. Consideration should be given to the establishment of a radio communication system prior to the beginning of construction and to
=
the maintenance of the system throughout the life of the project.
(3) Evacuation Plans. Evacuation plans should be prepared and implemented by the local jurisdiction controlling inundation areas. This would normally not be the dam agency or owner. Evacua.
tion plans should conform to local needs and vary in complexity in accordance with the type and degree of occupancy of the potentially affected area. The plans may include delineation of area to be evacuated; routes to be used; traffic control measures; shelter; methods of providing emergency transportation; I special procedures for the evacuation and care of people from institutions such as hospitals, nursing homes, and prisons; procedures for securing the perimeter and for interior security of the area; procedures for the lifting of the evacuation order and reentry to the area; and details indicating which organizations are responsible for specific functions and for furnishing the materials, equipment, and personnel resources required.
The assistance of local civil defense personnel, if available, should be requested in preparation of the evacuation plan. State and local law enforcement agencies usually will be responsible for the execution of
, much of the plan and should be represented in the planning effort. State and local laws and ordinances may require that other State, county, and local government agencies have a role in the preparation, review, approval, or execution of the plan. Before finalization, a copy of the plan should be furnished to the dam agency or owner far information and comment.
i (4) Stockpiling Repair Materials. Sujtable construction materials should be stockpiled
- for emergency use. "Ite amounts and types of construction materials needed for emergency repairs should y be determined based on the structural, foundation, and other characteristics of the dam; design and con-struction history; and history of prior problems.
3 38 .
l (5) Locating Local Repalt Forces. Arrangements should be made with, and a current list l maintained of, local entities, includmg contractors, and, Federal, State and local constrwtion depart. l ments, for possible emergency use of equipment and labor.
l (6) Training Operating Personnel. Technically qualified project personnel should bc '
trained in problem detection, evaluation, and appropriate remedial (emergency and non-emergency) measures. His is essential for proper evaluation of developing situations at all levels of responsibility which, irdtlally, must be based on at. site observations. A sufficient number of personnel should be tra to assure adequate coverage at all times, if a dam is operated by remote control, arrangements must be made for dispatching trained penonnel to the project at any tr.dication of dhtress.
(7) Increning Inspection Frequency. Frequency of appropriate surveillance activities sho be increued when the reservoir level exceeds a predettrmined elevation. Piezometers, water level gaug and other instruments should be read frequently and on schedule. The project structures f should be in.
npected as often as necessary to monitor conditions related to known problems and to detec change or new problems that could arise. Hourly or continuous surveillance may be mandated i stances. Any change in conditions should be reported promptly to the supervisor for further evalua The supervisor should issue additional instructions, as necessary, and alert repair crews and contrac for necessary repair work if developing conditions indicate that emergency repairs or other remed incasures may be required.
- d. Actions Upon Discovery of a Potentially Unsafe Condition Action to be tak' e n will depend on the nature of the problem and the time estimated to be availab remedial or mitigation measures. As time permits, one or more of the following actions will be req (1) Notification of Supervisory Personnel. This is essential, if time permits, since develo ment of failure could vary in some or many respects from previous forecasts or assumptions, an may be needed.'
(2) initiation of Predetermined Remedial Action. It is imperative that at least one technica l
quallfled individual,* previously trained in problem detection, evaluation, and remedial ac project or on call at all times. Depending on the nature and seriousness of the problem a available, emergency actions can be initiated, such as lowering the reservoir and holding water in ups reservoirs. Other actions to be taken include notifying appropriate highway and traffic control o promptly of any rim slides or other reservoir embankment failures which may endanger pu (3) Determination of Need for Public Notification. To the extent possibic, emergency si tions that wid require immediate notification of public officials in time to allow evacuation of the pote tially affected areas should be predefined for the use of management and project perso time is available, the decision to notify public officials that the dam can be expected to fall will be a predetermined supervisory level within the agency or owner organization. If failure la im already occurred, project personnel at the damsite would be responsible for direct notificatio public officials. The urgency ol' the situation should be made clear so that public official action imtnediately.
4 39
e i
t i
)
i I
i APPENDIX A FCCSET AD HOC INTERAGENCY COMMITTEE MEMBERS - ^
e
-t Meanbets
.i Jessph Friedkle PhWp hf. Sedth (Cheeresse) rh. UA lordee Assistaat IMewter tw Noteral Reneeroes and Coeumardel leesrusaleeni Seendary and Water em ;
ser, tees Washlagtee. DC - ,
Offke of Scisese med Tecteelesy Policy Wasidestee. DC Gary Wicise Depety Assisemet Seerotary for tend and Weser assessoas
- Wininas S. Divies Departmoet of the later6er
- Hydrelegy and M1: .Sg Breech Weehingese. DC DMales of Site Safety med Eevtreassental Amelysis .
Nedser Regeletery Conusessies Gerald R. Whees. Jr.
Weeblastem. DC Chief. Project Amstrels Beeme6 -
IJeemmed Pro) eses DMalee nan F. Begeer Federal Ensegy Regelsewy Ceemledes Derwtw. Eaglesatog IMelmies Wasidesses. DC 4 seu Ceaservades perties
-F_, _: " of Agrieeltere '
Weeningtoe. Dc ,
Consentant to OSTP Gewge L. seew '
cwst, ove sagtesedag and Design are t Dietslos of % Duig" tense A.Tsehmets ome w reginewing Dwige end Cessatedse 3 ,,,,, ,,,, ,,ci,,g ,,,, ,,,,,
Tsamassee Venry Aetheeter
. g ,g,,,ggy g 7 ,,,,,,,,
Enosvine, Tennesses Esarves,Teameens*
Doeste Delos Depety tw PeI6cy Ptseeing and IAghdestve Aestysts Deportement et the Army -
' Washington. DC ' '
o i
'4
, t i e
'V
$ A 1' .c
-+ , c,-, . -
+' -
o'.
APPENDIX B
~
Interagency Guidelines Subcommittee Members A. Site Investigation and Design (SID)
B. Construction (CON)
C. Operation and Maintenance (OPM) y en b
4 SID Teek Groep Members Ageery ideoencodes ,
Hydrelesr Departmeel of Agrtraiters (USDA)
... USDA4CS . Normen MIBet FS . Ferset service Army <erpe . V4rees Heges (Chairmes)
SC5. See Coenervedes Serv 6ce D0l-Bakee . Fred A. Beres E.. __ " of the Army (Army) FERC. Donale Terest Carpe . Carpe of Eaglesere NBC . Ed Hawkine Department of the laterter (D0f)
TT A . Pameld W. Newtee 5tA . Dersee of ladies Affaire ashmoingr 51M . Dessem of land Menegeemet USDA eC3. Al Geiger BOM.Beroes of Misse Aemy Corpe . Ems Estelesky meRec. serose of e-a -des D08-heRee . Andy Vikene .
IWS . Flah and Wuditte Servlee USGS . Jim Divine (Chainene)
MFAA. Mieles Enfeeeeeeeet med Seiety Administreeles NBC . Jehe EeBarber USGB U.S. Geelegical Server TVA . Doesid J. Relebeid FERC . Federal Emersy Regelesery rW Setsmie Fagleserlag itWC . lateressional Beemdery and Weaerema, .
USDA 4CS . Jim Telhet -
U.S. Seedse Armyterps . A. G. FreeMie NRC Nedeer Ulsgelasser ch DOI-Beret . Rishard W. Eremer (Chainese)
TVA.Teemessee Vener Aesherty NBC . Bishard McMetro TVA Theeses J. Abrahame A. SID Sehsomakens Menshees r'm George L h. Cneirsono Army {orps . Jake Seeleger USDA-SC5. Dettd C, teleses DOI-teRee . Jesse lages -
_ Aresyterps . Ereset L Dednes MIRA . Rehert Fetersee
- Dol BIM Rehert A W5se USGB . Henry W. Ceeher DOM . Weisse D. Weedhary - FERC . Harry Themes Beret . L T. Schertet TVA . James H. Ceessee (Chairnes)
FWS . Walter L Weel -
MIRA . Robert Fe)imoes USGS . Henry W. ra= ham FERC. Germed R. Wasse. Jr.
NBC . Wh S. Blvtes - -
TVA . George L Bushmene B.1 - q
..- . .--.-.-. _\
SID Task Ge ep Mossbers (constseed) C. OPM Sehesenmassee Members
. Germed E Wilmes. Jr.. Chearisse Hrdreekse USD A.lli . James A. Wolfe Arisy Carpe . See Powen Arar Cerys . Wililam F. BritesN DOI BeRec r Edwns C. Roeniles DOI.BIA . FWup Corke IM . Robert F. McVais . Bemee. Rep H. Bord
- MERA . Gas Cesser MESA . 5. Ascheer $ssede ,
FERC . Fremde Lee FTJIC . Soare Y. Coker !
TVA . Sveis Yigander (Chainnae) . GereW L Whees. Jr.
Ceeersee Deans _
. (thenege Brews lettial Chearmee. Reelred) i Army Corps . Kehh O'DesseE IBWC . T. R. Merela. P; mt of Sense ,
D05.BeRee . Gises Tarbes (Chainnee) TVA . HeroW C. Dettrer i F V S . 3137 F. Hortes FERC . Ese Hee Yeas * ()PM Task Groep Mesabers TVA . Earl L Spearman OPM Procedores Enh==h-t Dome USDA.8C3. Peel L Nylander USDA.8CS . Deved C. Renesse Areat Corps . Wililass F. Detenes ,
Army Cerys . Robert L Jesse (Chairines) Dol-BlA . PWup Cerhe DOI BeRee . Edwie W. Geer BeRee . Rey H. Bord (Chairmas)
BOM . Dea Esah MIRA . S. Aosheer Steele i FERC . Ceasemedes T}eemse FERC . Romaid A. t ==iah TVA . Saaneel D. Stees IBWC . T. R. Marsie TVA . Meige brewer. Jr.
R. CON Sebcommittee Members Perledte leeperelos Program DemaW A. ca==t==m . Chainnes USDA.FS . Jesse A. Wolfe USDA SC3. Nd F. Segest Arup Cerys . Ralph H. Fte Atar-Corps . Jeesph M. Noisee DOS-ReRee . B. A. Fitschard dol BeRee . DeeaW A. th ta-m FEBC . S. J. Osehipled
- . WIman R. G, a==. TVA . Hareid C. Boserer (Chairenas) ;
FWS . Weher L West Eenergener Aedee Flameles TVA . Herenne L Smaales Areer. Corps.Jasman L th==ha
- DOS BeRae . FJest C. Reper
- CON Teek Groep Meenhore FEBC. Seere Y. Coker (Chairanne) leapeettee . . .,
TVA . Rehert A. Shehoe 4 ,
Arar Corps . Jenoph M. Nelese (Chaenosa) - r
- ; D044eRee . Wlulass R. Grosselene TVA . Hennes L Samulas a -. - . -
Ceeerneser Quattr Comerel
' USDA 8CS . Non F. Begast (Chainnae)
', Army-Corps . Jeesph M. Neisse DOS FWS . Weher L West
. Seafnes Arup Corps . Jemaph M. Naisee DOI FWS . Waher L West (Chairman)
TVA . Heresse L Smaalag .
l Standard 6seeles of Matertain Temeles USDA.80B . Nes F. Begner dol Bease . WlElam R. Gremodees (Chainnae) .
. Dem L Chapelser Idemainemelos et AsespenWo Ceasernettee Moebeds AnspCorps . Jasoph M. Neimos DOHetes . Dean L Chapelear TVA. Hennes L e==el=v (Chairman)
Ceaseressies Deseemesselse USDA4C5. Nes F. Regest (Chairessa)
DOS-BeRee . Dean L Chapelear
. .TVA . Hamas L Semblog t
t O
.?
t
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APPENDIX C OSTP INDEPENDENT Metnbers REVIEW PANEL MEMBERS Mr. Rey E. Unaley Profenor l'rsak E. Perttas (Chairuss) Ilsdrocomp, Inc.
Department af Ord Eagloeertog Palo Alto, California I Massachanetts lastitute of Technology Cambridge, Maneckoutts Mr. Gordos W. Prescott Ikpartment of Geoedemas Profeseot Cartan R. ADes Purdne University .
Department of Geology W.12ferette, lediase .
Caufornia lasticate of Tuba logy i
Pasadena, Califorais Profeenor II. Boltoe Seed
', Department of Gru Entr,leeertag Dr. Die D'Appaionia University of Canfornia, Beriency D'Appeloats Consulting Eagloeers, fac. Berkeley, Califortda Pittsbergh, Peamsylvaans
- Profenw Erik II. Yanmartke Mr. Gerand W. Farqsher, Attorney Department of Ov0 Eagineettog .
g Tord Fargehar, Korablet & O'Neul Maanachawtts lastitute of Tetheology i
Wuhtagtes, DC Cambridge, Massachautts
?
Mr.11. Keith floaaker l Kentecky Department of Nataral Raoartes sad Consultant to OSTP tavbvemental Protecto.
Traak. fort, Kestocky
, Profemor Bruce A.1schanta Department of Ovu Englaneteg Professor L Doeglas James, Dtrator Umi,ersity of Teneennes Utah Water Research laborato*y s Knoxvine Teasessee Utah State University Legna, Utah Mr. Eric B. KoDgeard laternational t:mgineertog Coaspany
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APPENDIX D ACKNOWLEDGEMENTS The authority for preparation of the guidelines is given in Reviews were made by sutv:ommittee members and by repre-section I.B. They were prepared by to interagency swdelines sentatives of the agencies other than the prepe. ring agency and task group composed of the chairmen of the sutemmittees by L Douglas James of the Independent Review Panel. Major identtfled in APPENDIX B. Specific sections preparation contributory reviews wue made by representatives of the assignments were; major dam building agencies, BuRec, Corps, SCS. and TVA, and the Independent Review Panel member,Section I; SID chairman, George L Duchanan ("IYA).
Editing sad asseinbly of the final working draft for sub-Section !!. CON chairman, Donald A. Giampaoll inittal to PCCSET were bandled by the SID chairman (TVA).
(BuRec), and OPM chairman, Gerald R. Wilson (TERC); Oliver 11. Raine of the SID chairman's engineering staff with cooperation of L Dougiu James, representative of assM in the preparation and rWw of Mous podons of the Independent Review Pasiel (APPENDIX C) to the the guidelines and in the editing and assembly of the workJng guidelines task group, and Bruce A. Tschantt, consultang draft.
, to OSTP and advisor to the tank group.
Section lit.A. and Ill.B. SID chairuun Section Ill.C. CON chairman Section Ill.D. OPM chairman The chainnen wwe misted by their sub:ommittee and task group members (listed in APPENDIX Bs.
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APPENDIX E BIBLIOGRAPHY BUREAU OF RECIAMA110N The ikied references are selected as repeinestattee of Federal sgtsey and ottee pebbeadoes related to dam safety, had are Coacme Maamd,8th Edluos,197$
mot latend44 to be lactasive of dasa tuhoology.
Earth Mammal,2nd FAdos, IM4 GENERAL i Groemd Water Maasal.1st TAldos. Im I taginwrieg Feendatica Conference Proceedlags. PabihhedDemist of Gravtry Doms,1st FAttoa.1976 by Anmerken Socker of Clrd Engineerst li .
Desigs of Arch Osms,1st Edlues,1977 Inspection, Maintr*aance and Rehablutation of Old Dams, , , ,
Pacific Grove, CA, Im. . Dedge of Small Dams,2nd FAltion. IM Rev. Reprint 1977 St/ tty of Small Dants. Ileaniker, Nil,1974. Mensal for Safet? Evalsanos of Esisues Dams,1st Edidos, Im Reryonsaluty and liabluty of Pubik and Private Inter.
ests on Dsms, Podfk Grove, CA 1973.
CORPS OF ENGINEERS The Evaluation of Dam Safary, Padfk Grove, CA,1976.
Engieeering Mammak mt l.nsons from Dant incidents. Interandoed Comadsaios EM 111421602 Ilydrashe Desagt of Reseriotr Oudet en Large Dams,1973.
5tt**ts'*
lessant fron' Dom incidents, Lf5A. United States Com.
- c. terse Deast/American Society of Civil 1643 flydraalk Dodge of St.611 ways sdttee Eagle .ers,1973.
1993 Stabluty of Earth sad Rectful Dem Earth and Earth-Rock Dant. Shereid, Woodward, GlakumLi and Clevengst,1963. (Wik7) 1100 Instrussestation of Earth and Rockflil D***
fundamentals of Eenhquake Eatineerin:, Newusst sad Roseebtseth,1971, (Pres tico llall) 1911 Construedon Control for Earth and Rockftli Deses 1%6tk law 91.J47. Neuomal Program of taspection of Damit, U.S. 92nd Congress,1971. 1200 Crstits Dans Desige 1300 Earth sad Rockflu Dems General Design
' BURFAU OF MINIS sad Constraction Comendersdoms
-4300 lastromestation for Mcemarsusest of Str3ctural Behartoe of Concr%e Gravity IC 8755 Dedge Guide for Metal and Neametal Talltap 5esetaru Dispenal,1977 E.1 <
..m
- b O '
l
- L Eaglesertug Reports (ERh SOIL CONSERVATION SERYlCE '
ER 1110 2-50 Low Dvel Discharge f acWthe for Desw.
Nedcaal Eagleeerles Headbookt down of impoemdmeats he 4. Hydtdogy 14M Hydrologic Frequency Estimates Section g . Ensimwing Geology 1606 Earthquake Design and Analyens for Corps of Engineers Dans Section 19. Construction laspection NerionalProgmm oflarpecthva e/ Dams, Volsaw I, Appendts D, Recommended GuideUnu for Sqfety larportion of Dams, 3,eg,g,,, y,g,,,,,,
IMS TR53. A Calde for the Des 6sa and layout of Earth Emergency Spillways MINING ENTORCEMENT AND SAFETY ADMINISTRA. TR60. FM Dams sad Reservoirs TION See Mechaeace Notes:
Eastoeertog sad Destga Massal, Coal Refuse Disposal Facci-1, Tentante Cah for Demmising Gendaha of nw ties,1975 Masertaas Dssige Geldeuses for Cool Refuse PGes and Water, Sedi nent, 3. Sou Mechenk:s Considerstless for Embeskment Dans or Sierry impouadments and lispoundlag Strectuna, IM6 5. Flow Net Coestruction sad Use Coal Refste laspection Manual, IM6 TENNESSEE VALLEY AUTIlORITY NUCLEAR REGULATORY COMMISSION General Coestruction Specifkatiean:
No, G-2 f w Ptala and Releforced Concrete Regulatory Guides Related to *-^"'-.M Sefety and Coo.
struction for Nedear Power Plauta. No. G-9 for Roued Farthfl3 for Dame med Poww Planta No. G-26 for Pressere Groetleg of Rock Foundations
' 14 - Quality h W Requiteensts (Opern. with Portlano Cement g g,p EagleMag Procederes et 1.59 - Dee4s Basis floods for Nacien Power Pines, LtT7 EP 1.04. taspeedom and Malateenace of Noepower Water 1.M. Design Raponse Spectru for Seismac Desirpa of CostroI Projects 1.07
- taspect60s and Maistenance of Hydroelectr6c
! 1.M - Ossitty Assursacs Requireuests for the Drdge of
' Nodest Poww Plants,1976 1.04.Navisados Lock inspectices l
i 1.121-laspect'sa of Water 40strolStructares Amalated i with h %er Poww Planta 1977 NUREG 75/0g* Standard Review Ptsa for the Iteview of Safety Aartyds Reports foc Nacbear Poww Pinats. Office of Nuclear Remeter Regulo-tios.1975 i
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