ML19093A134
| ML19093A134 | |
| Person / Time | |
|---|---|
| Site: | Consolidated Interim Storage Facility |
| Issue date: | 04/01/2019 |
| From: | Consolidated Interim Storage Facility |
| To: | Office of Nuclear Material Safety and Safeguards |
| Shared Package | |
| ML19093A183 | List: |
| References | |
| E-53940 | |
| Download: ML19093A134 (45) | |
Text
Enclosure 5 Attachment B to SAR Chapter 2 (Partial).
associated with Response to RAI NP-2.4-1
C
- cooK~JOYCE INC,,.
. 'I ENGINEERING AND CONSULTING 812 WEST. ELEVEN.T
.. H
. 512-474-9097 AUSTIN, TEXAS 78701---
CENTRALIZED INTERIM STORAGE FACILITY DRAINAGE EVALUATION AND FLOODPLAIN ANALYSIS MARCH 2016 REVISED NOVEMBER 2016 REVI.S.ED DECEMBER 2016 REVISED FEBRUARY 2019 Prepared fot:
Waste Control Specialists LLC P.O. Box 1129 Andrews, Texas 78714 Preparec:I by:
Cook-Joyce, Inc.
812 West 111h Street, Suite 205 Austin, Texas 78701 This report is issued for permitting or licensing purposes. It is not intend WCS\\FINAL\\180591 R190206_C1SF REPORT Diana Dworaczyk P.E. No. 63724 06 February 2019 TEXAS REGISTERED ENGINEERING FIRM F-883*
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Cii TABLE OF CONTENTS SECTION PAGE
1.0 INTRODUCTION
............................................................................................................... 1 1.1 HYDROLOGIC DESCRIPTION................................................................................... 1 1.1.1 Hydrosphere........................................................................................................ 1 1.1.2 Site and Structures.............................................................................................. 3 2.0 FLOODS........................................................................................................................... 5 2.1 FLOOD HISTORY....................................................................................................... 5 2.2 FLOODPLAIN ANALYSIS DEVELOPED CONDITIONS............................................ 6 2.2.1 Description of Watershed.................................................................................... 6 2.2.2 Description of Hydrologic Analysis Methodology................................................ 7 2.2.3 Site Drainage and Model Strategy...................................................................... 9 2.2.3.1 Site Drainage............................................................................................. 9 2.2.3.2' Model Strategy......................................................................................... 1 O 3.0
SUMMARY
OF RESULTS.............................................................................................. 11
4.0 CONCLUSION
S.......................................................................................,...................... 12 5.0 OTHER CONSIDERATIONS.......................................................................................... 13
6.0 REFERENCES
................................................................................................................ 14 WCSIFINAL\\180591 R190206_C1SF REPORT ii REV1SION3 06 FEBRUARY 2019
TABLE 1
2 3
FIGURE 1.1-1 1.1.2-1 1.1.2-2 2.2.1-1 APPENDIX APPENDIX A APPENDIX B APPENDIX C APPENDIX D APPENDIX E ADDENDUM LIST OF TABLES POST-DEVELOPMENT DRAINAGE AREAS - PEAK FLOW POST-DEVELOPMENT DRAINAGE AREAS - RUNOFF VOLUMES POST-DEVELOPMENT ANALYSIS POINTS-PEAK ELEVATION LIST OF FIGURES SITE LOCATION AND SURROUNDING TOPOGRAPHY MAP DEVELOPED DRAINAGE PLAN DEVELOPED DRAINAGE AREA MAP SOILS BOUNDARY MAP LIST OF APPENDICES FLOOD PLAIN STUDY, FEBRUARY 2004 SOIL SURVEY CALCULATIONS HEC-HMS OUTPUT HEC-HMS INPUT (CD)
LIST OF ADDENDA ADDENDUM A BERM BREACH ANALYSIS Cii WCS\\FINAL\\180591 R190206_C1SF REPORT iii REVISION 3 06 FEBRUARY 2019
Cii
1.0 INTRODUCTION
This report presents the results of a hydrologic and hydraulic analysis of the proposed conditions in and around the area of the Centralized Interim Storage Facility (CISF) proposed to be licensed by the Nuclear Regulatory Commission at the Waste Control Specialists, LLC (WCS) site located in Andrews County, Texas. This report is prepared in support of the Safety Analysis Report (SAR) as described at 1 O CFR 72.24 and addresses items contained in the "Standard Review Plan for Spent Fuel Dry Storage Facilities", NUREG-1567, dated March 2000, Section 2.4.4 Surface Hydrology.
1.1 HYDROLOGIC DESCRIPTION The CISF site is located in western Andrews County, Texas nearly at the Texas - New Mexico border, just north of Texas Highway 176 approximately 31 miles west of Andrews, Texas and 5 miles east of Eunice, New Mexico. There are no maps of special flood hazard areas for this location published by the Federal Emergency Management Agency (FEMA). The Site Location and Surrounding Topography Map, Figure 1.1-1, shows the CISF site location with respect to the surrounding topography and drainage features and the WCS property boundary.
1.1.1 Hydrosphere From a surface water perspective, the general area is characterized by ephemeral drainages, sheet flow, minor gullies and rills, internally-drained playas, and a salt lake basin (identified on Figure 1.1-1 as the Depression Pond).
The salt lake basin is the only naturally-occurring, perennial (year-round) water body located near the CISF site; the internally-drained salt lake basin is located approximately 5 miles from the eastern boundary of the CISF site and rarely has more than a few inches of water at scattered locations within the bottom footprint. Surface drainage from the CISF site does not flow into this basin. Other perennial surface water features are man-made, including various stock tanks (often replenished by shallow windmill wells) located across the area and the feature denoted as the Fish Pond on Figure 1.1-1, which is located at the existing Permian Basin Materials quarry west of the CISF site and is also replenished by well water. In addition, Sundance Services, LLC operates the Parabo Disposal Facility for oil and gas waste on portions of the Permian Basin Materials quarry property. Water collects periodically in excavated and/or diked areas at this disposal facility and in the active quarry areas at this property adjacent to and west of the WCS property in New Mexico.
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Cii Baker Spring, another man-made feature, is located at a historic quarry on WCS property about 2,150 ft west of the CISF site in Lea County, New Mexico. This feature was formed by excavation of the caliche caprock to the top of the underlying red bed clays. After periods of rainfall, the depression holds water for some period until it evaporates. During wet cycles, the depression may hold water for an extended period; during dry cycles, the depression may be dry for extended periods.
The National Oceanic and Atmospheric Administration's National Weather Service Office for Hobbs, New Mexico indicates that the minimum average annual precipitation recorded is 2.01 inches in 2011 and the maximum average annual precipitation recorded is 32.19 inches in 1941.
The annual precipitation on average is approximately 14 inches.
The CISF site is located on the southwest-facing slope that transitions from the Southern High Plains to the Pecos Valley physiographic section. The Southern High Plains is an elevated area of undulating plains with low relief encompassing a large area of west Texas and eastern New Mexico. In Andrews County, the southwestern boundary of the Southern High Plains is poorly defined, but in this report is considered to be where the caprock caliche is at or relatively close to surface, such as on and near the CISF site.
The main surface water drainage in the area is Monument Draw, an ephemeral stream about 3 miles west of the WCS site in New Mexico. Ephemeral streams or drainage ways flow briefly only in direct response to precipitation in the immediate locality. Monument Draw is a reasonably well-defined, southward-draining feature (although not through-going) that is identified on the USGS topographic maps that serve as the base map source for Figure 1.1-1.
An ephemeral drainage feature, referred to as the Ranch House Draw crosses the WCS property from east to west, generally to the south of the CISF site, as shown on Figure 1.1-1. This feature is discernible from the topographic relief depicted on Figure 1.1-1, although it is much less pronounced than Monument Draw. This drainage feature is a relict drainage way that is choked with windblown sand and is not through-going to Monument Draw. Most of the drainage from the area of the CISF site is down slope toward the Ranch House Draw, with a small portion of the drainage from this area toward the southwest.
Surface water eventually infiltrates into the windblown sands and dune fields to the south and southwest of the CISF site.
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Cii There are no ephemeral drainages that cross the CISF site. Most of the immediate area of the CISF site is drained from northwest to southeast by sheet flow. Sheet flow is a term describing overland flow or down slope movement of water taking the form of a thin, continuous film.
Playas, or small, internally-drained basins, occur on the WCS property. The playas are dry most of the time. Some of the playas occasionally hold water after relatively large precipitation events; however, the ponded water rapidly dissipates through infiltration, evaporation, and plant uptake.
An established playa basin is present on the eastern edge of the CISF site. Surface topography maps indicate approximately 10 ft of relief in the playa.
The combination of low annual precipitation, relatively high potential evapotranspiration, permeable surficial soils down gradient of the CISF site, and topographic relief results in well-drained conditions. The engineering design and *construction of the CISF site will eliminate areas that might promote ponding. Diversion berms and a collection ditch will direct stormwater from upstream drainage areas around the CISF.
- There are no public or private surface water drinking-water supplies in the site vicinity. Potable water supply for the WCS facility is provided by the City of Eunice, which gets its water from wells in the Hobbs area. There are scattered windmills in the general area that take water from isolated pockets of groundwater perched on top of the red bed clay. This water is utilized primarily for livestock watering.
1.1.2 Site and Structures The CISF site is defined as the area within the owner controlled fence and is approximately 320 acres as depicted on the Developed Drainage Plan, Figure 1.1.2-1. The CISF site is undeveloped and the existing land surface is fairly flat with an average slope of 0.8 percent(%). The existing maximum and minimum elevations of the site are about 3520 ft and 3482 ft msl, respectively. The cover type is desert shrub. The existing WCS railroad is generally aligned parallel with and south of the proposed southern CISF site boundary.
The CISF storage area, which is within the CISF site, is defined as the area within the protected area fence whose boundary is defined by a rectangle 2360 feet by 2430 feet, as indicated on the Developed Drainage Plan, Figure 1.1.2-1.
Included in the storage area are the security/administration building, the cask handling building, the storage pads and a portion of the WCS\\FINAL\\180591 R190206_C1SF REPORT 3
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Cii CISF rail side track. The CISF storage area is approximately 132 acres and is graded for surface drainage with slopes of approximately 0.8 % from the northwest to the southeast. Developed elevations across the CISF storage area range from 3506 ft msl at the northwest corner to 3486 ft msl near the southeast corner.
All of the surface water runoff from the storage area will drain into the large playa southeast of the site. Flow arrows on Figure 1.1.2-2, Developed Drainage Area Map provide the detailed drainage patterns for the CISF site.
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Cii 2.0 FLOODS There is no evidence that the CISF site area has experienced flooding in the past. The ranch house drainage within the WCS property was evaluated as part of a Flood Plain Study conducted in February 2004 (Revised December 2004 and March 2006) for the Application for License to Authorize New-Surface Land Disposal of Low-Level Radioactive Waste (LLRW) that was approved by the Texas Commission on Environmental Quality (TCEQ) in 2009 as Radioactive Material License No. R04100. The 2004 Flood Plain Study as revised through March 2006 is provided as Appendix A and includes maps depicting the drainage areas within the WCS property and the location of the 100-year, 500-yearand Probable Maximum Precipitation (PMP)flood plain.
The 100-year flood plain extends across the southern portion of the WCS property area along the ranch house drainage. The northernmost limit of the 100-year floodplain is approximately 4,000 ft southeast of the CISF site while the northernmost limits of the 500-year and PMP floodplains are 3965 feet and 3895 feet southeast of the CISF site respectively.
The prior floodplain analysis indicated that the PMP elevation of the large playa located mostly east of the CISF site is 3488 ft msl. A portion of the CISF site is located over the large playa.
Elevations of the storage pads, security/administration building, and the transfer facility are above 3490 ft msl.
An analysis of the drainage features around the CISF site is performed for the PMP to ensure that the structures important to safety are safe from flooding.
2.1 FLOOD HISTORY The climate of the area is classified as semiarid, characterized by dry summers and mild, dry winters. Annual precipitation on average is approximately 14 inches and annual evaporation exceeds annual precipitation by nearly five times. The area is subject to occasionally winter storms, which produce brief snowfall events of short duration.
Rainfall records from July 2009 through December 2015, provided by WCS from a weather station near the CISF site, indicate an average annual rainfall of 12.6 inches and a maximum twenty-four hour rainfall total of 3.62 inches. According to WCS personnel, surface water runoff has not overflowed roads or existing drainage features at the WCS facility during this time frame.
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Cii 2.2 FLOODPLAIN ANALYSIS DEVELOPED CONDITIONS This analysis identifies the limits of the watershed in which the CISF site is proposed to be located and determines the local peak flow rates and water elevations at the watershed analysis points resulting from the 100-year and 500-year frequency storm events and the Probable Maximum Precipitation event (PMP) after the CISF site is fully developed. This analysis also identifies the location of the local PMP floodplain associated with a large playa/depression located within the subject watershed.
2.2.1 Description of Watershed The contributing watershed that crosses the CISF site contains about 869 acres (1.4 square miles). For the most part, the CISF site is located on top of a hill and will be grad~d to allow drainage away from the site. Fully developed conditions result in four distinct drainage areas that predominantly slope away from the CISF site. The Developed Drainage Area Map, Figure 1.1.2-2, identifies the developed drainage area boundaries in relation to the CISF site and the associated analysis points described below.
Drainage Area P DA 1 contains 100.9 acres and drains the northwest portion of the site outside of the storage area. Analysis Point P AP 1 is located where surface water runoff from P DA 1 flows across State Line Road.
Drainage Area P DA 2 contains 46.1 acres and drains the southwest portion of the CISF site contained between the existing WCS railroad and the CISF rail side track outside of the storage area. Analysis Point PAP 2 is located at the western intersection of the CISF rail side track and the existing WCS railroad. Drainage Area P DA 3 contains 42.8 acres and drains the southeast portion of the CISF site bounded by the existing WCS railroad and the. CISF rail side track. Surface water runoff from P DA 3 discharges into the large playa located east of the facility. Drainage Area P DA 4 contains 679.3 acres encompassing the large playa and the majority of the CISF site; surface water from this portion of the CISF site also discharges into the large playa. Analysis Point PAP 3 refers to the location where surface water runoff in the large playa will overtop the existing ground to the south.
The watershed is located in Andrews County, Texas. The Custom Soil Resource Report for Andrews County, Texas, and Lea County, New Mexico, prepared by the United States Department of Agriculture (USDA), Natural Resources Conse~ation Service (NRCS), located in Appendix B, shows the watershed contains soils from the Blakeney and Conger, Jalmar-Penwell, WCS\\FINAL\\18059\\
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Cii Ratliff, and Triomas and Wickett series. These soils are classified with the hydrologic groups A,
- Band D. Group A soils have high infiltration and transmission rates. Group B soils have moderate infiltration and transmission rates. Group D soils have very low infiltration and transmission rates.
The Soils Boundary Map with the CISF site location, topographic information and drainage area boundaries is included as Figure 2.2.1-1.
2.2.2 Description of Hydrologic Analysis Methodology Surface water runoff from the watershed in which the CISF site is located is modeled using the U.S. Army Corps of Engineers Hydrologic Engineering Center's Hydrologic Modeling System (HEC-HMS), version 4.0. The rainfall amount for the 100-year frequency storm event is taken from the USDA Soil Conservation Service (SGS) Texas Engineering Technical.Note No. 210 TXS, October 1990 (TETN 210). A 24-hour storm duration is used. The 100-year 24-hour rainfall amount from TETN 210 for the CISF site is six (6) inches and is the same rainfall amount used in the floodplain study in Appendix A. The 500-year, 24-hour and PMP, 72-hour rainfall amounts are taken from the floodplain study in Appendix A and are 8. 71 inches and 40.5 inches, respectively. The precipitation amounts used as input for the HEC-HMS model are as follows:
Return Period 100-Year, 24 Hour 500-Year, 24 Hour PMP, 72 Hour Rainfall (In.)
6.0 8.71 40.5 Peak discharges from small watersheds are usually caused by intense, brief rainfalls. Utilizing synthetic rainfall distribution as taken from TETN 210 in this case is common practice instead of using actual storm events. The synthetic Type II, 24-hour rainfall distribution for Andrews County, Texas, as shown on Figure 1 of TETN 210, and the SCS dimensionless unit hydrograph method are used for the model. The method requires curve numbers to indicate the runoff potential of a hydrologic soil-cover complex and watershed lag to model watershed response.
The development of these values is described in the following paragraphs.
The curve number (CN) is computed based on land use, cover type, hydrologic condition and son group. A December 16, 2015 site visit supported determination of land use, cover types and hydrologic condition. Hydrologic condition indicates the effects of cover type and treatment on WCS\\FINAL\\18059\\
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Cii infiltration and runoff. The hydrologic condition of the cover at the site is considered poor. The soil group information is taken from the Soil Report in Appendix B. The variability of the CN from rainfall intensity and duration, total rainfall, soil moisture conditions, cover density, stage of growth, and temperature are collectively accounted for in the Antecedent Runoff Condition (ARC).
The three classes of ARC are as follows: I for dry conditions, II for average conditions, and Ill for wetter conditions. Figure 5 of TETN 210 indicates that the ARC across the state of Texas varies greatly and Andrews County is ARC I. In order to be conservative and check the sensitivity of the model to the various ARC conditions, all three classes are used in the CN determinations and the model.
The USDA NRCS, Part 630 Hydrology, National Engineering Handbook (NEH) explains that lag is the delay between the time runoff from a rainfall event over a watershed begins until runoff reaches its maximum peak.
Lag is* empirically estimated as six-tenths (0.6) of the time of concentration, (USDA NRCS, Part 630, NEH, Equation 15-3). The time of concentration is the time it takes for runoff to travel from the hydraulically most remote part of a watershed to a point of consideration. In hydrograph analysis it represents the time from the end of "excess rainfall" to the point of inflection of an SCS unit hydrograph.
Time of concentration is computed by determining the travel times for different segments of the flow path. The segments consist of sheet flow, shallow concentrated flow and concentrated flow.
The sheet flow and shallow concentrated flow components are calculated for all of the drainage areas using the equations from USDA SCS Technical Release 55, Urban Hydrology for Small Watersheds. Drainage Areas P DA 1 and P DA 2, as shown on Figure 1.1.2-2, also exhibit channelized flow. Broad channelized flow occurs in P DA 1 as the surface water flows southwest out of the CISF site and crosses State Line Road. Channelized flow occurs in P DA 2 as the surface water flows southwest in the existing ditch along the northern side of the existing WCS railroad.
Concentrated flow is calculated based on the flow velocity for the channel being analyzed. Channel velocities are calculated using Manning's Equation or they are estimated based on the results of the HEC-HMS model. All time of concentration parameters for the various drainage areas are included in Appendix C, Calculations.
Elevation, storage and cross-section data are developed for P DA 2, P DA 3 and the playa/depression located within the subject watershed to determine their effect on the runoff from WCS\\FINAL\\ 18059\\
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Cii these areas and are included in Appendix C. All watershed parameters that are topography dependent are based on the WCS provided aerial survey dated May 29, 2014 flown by Dallas Aerial Surveys, Inc and the WCS provided proposed CISF elevations.
2.2.3 Site Drainage and Model Strategy The CISF site drainage features consist of a collection ditch and four culverts through the CISF rail side track that are located as shown on the Developed Drainage Plan, Figure 1.1.2-1. The design criterion for the site drainage features are the 100-Year, 24 Hour, ARC I, peak flow rates as determined by HEC-HMS. Whenever possible, surface water runoff will be maintained as sheet flow. Conservative input parameters and strategies are used in the HEC-HMS modeling of the peak flow rates.
2.2.3.1 Site Drainage Surface water runoff from the up gradient area north of the storage area will be diverted by a collection ditch located just north of the storage area boundary as shown on Figure 1.1.2-1.
Onsite surface water runoff will be mainly sheet flow off of the sloped storage pads and the sloped areas in between the pads. The land surface adjacent to the eastern and western perimeters of the storage pads will be sloped to drain as sheet flow toward the protected area fence and beyond through the owner controlled area fence. Surface water runoff between the collection ditch and the northern storage pads within the storage area will sheet flow to the southeast. Surface water runoff south of Phase 1 storage pad will drain southeast into Culvert 2 under the CISF rail side track just west of the cask handling building. Surface water runoff south of the Phase 5 storage pad and the CISF rail side track will sheet flow to the east.
The cask handling building roof drains half to the north and half to the south. The western portion of the area between the CISF rail side track and the existing railroad outside of the storage area will drain to the west with some of the surface water runoff flowing through the existing culvert under the WCS railroad crossing at State Line Road and the rest of it flowing through Culvert 1 into existing surroundings. The eastern portion of the area between the CISF rail side track and existing railroad will drain to the east and empty into the large playa through Culverts 3 and 4.
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Cii 2.2.3.2 Model Strategy Conservative parameters are input into the HEC-HMS model to determine peak runoff rates and overflow elevations. Conservative assumptions include the following: (1) all areas inside the storage area are assumed to be impervious for the CN calculation; (2) all three ARC conditions are used for the CN calculation even though Andrews County exhibits ARC I conditions; (3) no consideration is given to initial losses or infiltration rates of the precipitation; (4) all culverts are presumed clogged and do not allow any flow through them; and (5) the collection ditch and berms are not in place in order to model the greatest possible area contributing runoff irito the playa.
Surface water runoff at the clogged culverts in P DA 2 and P DA 3 and at the outflow of the large playa are modeled as reservoir elements in HEC-HMS. To stimulate flow out of these areas the non-level dam top routine is used with a discharge coefficient of 2.6.
The probable maximum flood (PMF) flow is modeled over the existing railroad and the proposed CISF rail side track.
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3.0
SUMMARY
OF RESULTS C..
. II The Developed Drainage Area Map, Figure 1.1.2-2 delineates the subject watershed including drainage areas and analysis points. The 100-year, 500-year, and PMP peak discharges for each drainage area and ARC condition as determined by the HEC-HMS model are shown in Table 1, Post-Development Drainage Areas - Peak Flow. The 100-year, 500-year, and PMP runoff volumes for each drainage area and ARC condition as determined by the HEC-HMS model are shown in Table 2, Post-Development Drainage Areas - Runoff Volumes.
The 100-year, 500-year, and PMP water surface elevations at analysis points as determined by HEC-HMS for every ARC condition are shown in Table 3, Post-Development Analysis Points -
Peak Elevation.
At Analysis Point 1, the peak discharge resulting from all modeled storm events flows over State Line Road. The peak discharge (during the PMP and ARC Ill conditions) is 424 cubic feet per second (CFS). The maximum depth of flow over the road (during the PMP and ARC Ill conditions) is approximately 0.8 ft. which is equivalent to elevation 3487.3 ft. msl.
The peak discharge resulting from all modeled storm events flows over the railroad tracks at Analysis Point 2. The peak discharge (during the 500-year and ARC Ill conditions) is 284 CFS.
The maximum depth of water over the rail (during the 500-year and ARC Ill) is approximately 1.4 ft. which is equivalent to elevation 3466.4 ft. msl.
The playa/depression contains all the runoff from drainage areas P DA 3 and P DA 4. The limit of the PMP, ARC Ill condition, water surface elevation of the playa/depression based on the topographic information provided by WCS is 3488.9 ft. msl and is shown on Figure 1.1.2-2, Developed Drainage Area Map. The results indicate that the playa/depression does not discharge during the 100-year frequency event but does discharge at Analysis Point 3 during the other modeled events. The peak discharge (during the PMP and ARC Ill conditions) flowing out of the playa is 3005 CFS.
The depth of the PMP, ARC Ill, peak discharge flow over the railroad tracks at Analysis Point 3 is approximately 1.5 ft. which is equivalent to elevation 3488.9 ft. msl.
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Cii
4.0 CONCLUSION
S The local PMP floodplain analysis yields the PMF elevation near the CISF site of 3488.9 ft msl.
Elevations of the storage pads vary from 3490 ft msl to 3504 ft msl. Elevations of the foundations of the security/administration building and the transfer facility are 3496 ft msl and 3493 ft msl, respectively.
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Cii 5.0 OTHER CONSIDERATIONS The naturally occurring playa/depression will reach its maximum elevation for a brief time as the surface water flows out over the rail and the natural ground and infiltrates into the existing ground.
At the peak elevation the area of the water surface in the playa/ depression is approximately 280 acres which is too small to produce any wind wave activity.,
No PMP analysis of perennial streams or rivers is considered since they do not exist in the vicinity of the CISF site.
There are no dams on any upgradient areas from the site; therefore, no analysis is required.
Since no large bodies of water exist near the site, no surge, seiche, or ice flooding is possible.
The site is located 480 miles from the Gulf of Mexico, which is the nearest coastal area; therefore, no tsunami sea waves are possible.
There are no liquid releases that result from the normal operation of the CISF.
The local short-term overland flow depth of surface water runoff and velocity on the CISF Phase 1 pad for the 500-year rainfall event are calculated using Manning's Equation. The maximum rainfall intensity for all analyzed storms is used which is the 500-year rainfall event and is taken from the HEC-HMS output. Calculations are found in Appendix C and the results are as follows:
Maximum depth: 1.1 inches Maximum velocity: 1. 7 feet/second Berms and ditches upgradient of the storage area will be constructed of on-site available compacted red bed clay and ~rmored with on-site availab_le caliche in order to minimize erosion and seepage. Inspection of the berms for erosion and ditches for se~iment buildup will be part of the routine inspection operations for the site. Areas of the site impacted by erosion and sediment buildup will be repaired to original grades. Inspection and maintenance will occur after normal and extreme precipitation events and through all phases of the facility.
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Cii
6.0 REFERENCES
Waste Control Specialists LLC, Application for License to Authorize Near-Surface Land Disposal of Low-Level Radioactive Waste, Appendix 2.4.1: Flood Plain Study, March 2006.
United States Department of Agriculture, Natural Resources Conservation Service. Custom Soil Resource Report for Andrews, County, Texas, and Lea County, New Mexico, December 2015.
United States Department of Agriculture, Soil Conservation Service.
Texas Engineering Technical Note No. 210-18-TX5, October 1990 (TETN 210).
United States Department of Agriculture, Natural Resources Conservation Service. Part 630 Hydrology, National Engineering Handbook (NEH}, Chapter 15, Time of Concentration, May 2010.
United States Department of Agriculture, Natural Resources Conservation Service Technical Release 55. June 1986. Urban Hydrology for Small Watersheds.
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WCS\\FINAL\\ 150521 R161212_C1SF REPORT TABLES Cii REVISION 2 12 DECEMBER 2016
ARCI ARC II ARC Ill WCS\\FINAL\\ 15052\\
T161212_TABLES TABLE 1 WCS - CISF FLOOD ANALYSIS POST-DEVELOPMENT DRAINAGE AREAS - PEAK FLOW Drainage 100YR SOOYR PMP Area Peak Flow Peak Flow Peak Flow (CFS)
(CFS)
(CFS)
P DA 1 118.3 245.4 410.7 PDA2 118.1 209.2 191.1 PDA3 127.5 218.2 178.4 PDA4 803.6 1523.1 2786.9 Drainage 100YR SOOYR PMP Area Peak Flow Peak Flow Peak Flow (CFS)
(CFS)
(CFS)
P DA 1 223.4 373.1 421.5 PDA2 170.8 264.8 193.1 PDA3 173.8 265.4 179.8 PDA4 1324.0 2113.8 2839.4 Drainage 100YR SOOYR PMP Area Peak Flow Peak Flow Peak Flow (CFS)
(CFS)
(CFS)
P DA 1 292.0 440.6 424.2 PDA2 193.2 284.4 193.5 PDA3 191.1 279.9 180.1 PDA4 1574.7 2346.9 2849.7 Cii REV1SJON2 12 DECEMBER 2016
TABLE 2 WCS - CISF FLOOD ANALYSIS POST-DEVELOPMENT DRAINAGE AREAS - RUNOFF VOLUMES ARCI ARC II ARC Ill WCS\\FINAL\\150521 T161212_TABLES Drainage Area PDA 1 PDA2 PDA3 PDA4 Drainage Area PDA 1 PDA2 PDA3 PDA4 Drainage Area PDA 1 PDA2 PDA3 PDA4 100YR Runoff Volume (IN) 2.09 3.09 3.38 2.62 100YR Runoff Volume (IN) 3.68 4.52 4.74 4.20 100YR Runoff Volume (IN) 4.96 5.41 5.53 5.18 500YR PMP Runoff Volume Runoff Volume (IN)
(IN) 4.11 33.97 5.44 36.38 5.81 36.94 4.84 35.35 500YR PMP Runoff Volume Runoff Volume (IN)
(IN) 6.17 37.48 7.14 38.76 7.38 39.05 6.78 38.30 500YR PMP Runoff Volume Runoff Volume (IN)
(IN) 7.63 39.34 8.11 39.88 8.23 40.00 7.87 39.61 Cii REV1SION2 12 DECEMBER 2016
TABLE 3 WCS - CISF FLOOD ANALYSIS POST-DEVELOPMENT ANALYSIS POINTS - PEAK ELEVATION Analysis 100 YR 500YR PMP Point MAXWSE MAXWSE MAXWSE (FT)
(FT)
(FT)
PAP 1 3486.9 3487.1 3487.2 PAP2 3466.0 3466.3 3466.2 PAP3 3484.4 3485.8 3488.8 Analysis 100 YR 500YR PMP Point MAXWSE MAXWSE
.MAXWSE (FT)
(FT)
{FT)
PAP 1 3487.0 3487.2 3487.3 PAP2 3466.2 3466.4 3466.2 PAP3 3485.4 3486.5 3488.9 Analysis 100 YR 500YR PMP Point MAXWSE MAXWSE MAXWSE (FT)
{FT)
(FT)
PAP 1 3487.1 3487.3 3487.3 PAP2 3466.2 3466.4 3466.2 PAP3 3486.0 3486.8 3488.9
- 1. Water surface elevation (WSE) represent elevation above mean sea level (AMSL).
Cii
- 2. Elevations are taken from topographic aerial survey provided by Dallas Aerial Surveys, Inc., flown 5-29-2014.
10220 Forest Lane, Dallas, Texas 214-349-2190, 800-862-2190, Fax 214-349-2193.
WCS\\FINAL\\15052\\
T161212_TABLES REV1SION2 12 DECEMBER 2016
WCS\\FINAL\\ 18059\\
R190206_C1SF REPORT FIGURES Cii REVIS10N3 06 FEBRUARY 2019
S\\CAO\\VIC'S\\1SOS2 CJSF Aoodphin\\lSOS2007R.2
- OCVElOPEO DAAINAGE PlAN.ttwg. 1/22J2019 2"1S.:12 PM 600 300 0
(SCALE IN FEEl) ill£till
_ CISF OWNER CONTROLLED AREA FENCE EXISTING MINOR CONTOUR
-3490-EXISTING MAJOR CONTOUR PROPOSED MINOR CONTOUR
- 3490-PROPOSED MAJOR CONTOUR NOTES:
- 1.
EXISTING TOPOGRAPHIC INFORMATION WlTHIN LIMITS SHOWN PR0\\1DED BY DALLAS AERIAL SURVEYS, INC., FLOl',l,I 5-29-2014. 10220 FOREST LANE, DALLAS, TEXAS 214-349-2190, 800-862-2190. FAX 214-349-2193.
- 2.
EXISTING TOPOGRAPHIC INFORM A 110N OUTSIDE OF THE LIMITS SHOWN IS BASED ON A DIGITAL ELEVATION MODEL (DEM) PR0\\1DED BY THE TEXAS NA TUR AL RESOURCE INFORMATION SYSTEM (TNRIS).
THIS DRAWING IS ISSUED FOR PERMITTING OR LICENSING PURPOSES. IT IS NOT INTENDED FOR BIDDING OR CONSTRUCTION PURPOSES.
OJCCT P+O. 15052.01 MO. 150520071'2 EIT 1 r:E 1 SlfEETS
""""°' 1.1.2-1 DIANA DWORACZYK P.E. No. 63724
S:\\CAO'\\WCS\\15052 CISF Aoodplaln\\15052005R2 - l.12-2.dv,g. l2/11/1016 2:47:53 PM 1000 500 0
1000 \\
(SCALE IN FEET)
LEGEND
- * * * * * * *
- DRAINAGE AREA BOUNDARY
____ WAITS OF TOPOGRAPHIC SURVEY BY DALLAS AERIAL SURVEY 5-29-2014 0
ANALYSIS POINT DIRECTION OF FLOW APPROXIMATE PLAYA PMP WSE
-- - -- FLOODPLAIN LIMIT CISF OWNER CONTROLLED AREA FENCE EXISTING MINOR CONTOUR
-3490-EXISTING MAJOR CONTOUR PROPOSED MINOR CONTOUR
- 3490-PROPOSED MAJOR CONTOUR NOTES:
- 1.
EXISTING TOPOGRAPHIC INFORMATION WITHIN LIMITS SHOWN PROVIDED BY DALLAS AERIAL SURVEYS, INC., FLOWN S 2014. 10220 FOREST LANE, DALLAS, TEXAS 214-349-2190, 800-862-2190, FAX 214-349-2193.
EXISTING TOPOGRAPHIC INFORMATION OUTSIDE OF THE LIMITS SHOWN IS BASED ON A DIGITAL ELEVATION MODEL (DEM) PROVIDED BY THE TEXAS NATURAL RESOURCE INFORMATION SYSTEM (TNRIS).
- 3.
DEVELOPED DRAINAGE AREAS REPRESENT THE ABSENCE OF PROPOSED BERMS OR DITCHES.
2 2/18 EMOVE Fl.OW PATH INFO, DO DD E\\1SE ORAlt.lAGE. AREAS.
ROPOSEO CONTOURS. PV.YA MIT DD REV. DAlE C
- caaK-JDYCE INC, ENGINEERING ANO CONSULTING 812 YIEST ELEVENTH 512-474-9097
-- AUSTIN, lDCAS 78701--
HUB & 'M!E CERTlflED TEXAS R(GIS'TIRED ENGINEERING FlRIA r-Ml
?RO,.£C'J\\
CENlRAL INTERIM STORAGE F AGILITY ANDREWS COUNTY, TEXAS SHCET T\\l\\..E; DEVELOPED DRAINAGE AREA MAP SCM.(:
SEE BAR SCALE PRG.ECT NO. 15052.01 CJ NO. 1505l005R2 SHEET 1 Of I SHEETS
S:\\CAO\\WCS\\15052 CISF Aoodplain\\1SOS2006Rl
- 21.l*Ldwg, 12/12/2016 2:44:07 PM P DA4 679.3AC.
NOTES:
1000 \\
(SCALE IN FEET)
SOILS BOUNDARY
LIMITS OF TOPOGRAPHIC SURVEY BY DALLAS AERIAL SURVEY 5-29-2014 CISF O'MIIER CONTROLLED AREA FENCE
- * * * * * * *
- DRAINAGE BOUNDARY
REDBED /
GAUCHE STOCKPILE AREA Soils Information Symbol Group Name BcB D
Blakeney & Conger lmB A
Ima JPC NB Jalmar-Penwefl RaB B
Ratliff TwB B
Triomas & Wickett BS AIB Brownfield-Springer SE D
Simona SR D
Simona-Upton County Andrews Co, TX Andrews Co, TX Andrews Co, TX Andrews Co, TX Andrews Co, TX Lea Co, N.M.
Lea Co, N.M.
Lea Co, N.M.
EXISTING TOPOGRAPHIC INFORMATION ~THIN LIMITS SH0\\\\111 PROVIDED BY DALLAS AERIAL SURVEYS, INC.. FLOWN 5-29-2014. 10220 FOREST LANE, DALLAS, TEXAS 214-349-2190, 800-862-2190, FAX 214-349-2193.
- 2. EXISTING TOPOGRAPHIC INFORMATION OUTSIDE OF TI-IE LIMITS SHOWN IS BASED ON A DIGITAL ELEVATION MODEL (DEM)
PROVIDED BY THE TEXAS NATURAL RESOURCE INFORMATION SYSTEM (TNRIS).
SOIL INFORMATION TAKEN FROM US DEPARTMENT OF AGRICULTURE, NATURAL RESOURCES CONSERVATION SERVICE CUSTOM SOIL RESOURCE REPORT FOR ANDREWS COUNTY, TEXAS, AND LEA COUNTY, NEW MEXICO, DATED DECEMBER 22 2015
- 4.
DEVELOPED DRAINAGE AREAS REPRESENT THE ABSENCE OF PROPOSED BERMS OR DITCHES.
r............,,,,, /1 lrz)1
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ANDREWS COUNTY, TEXAS
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THIS DRAWING IS ISSUED FOR PERMITTING OR LICEN SING PURPOSES. IT IS NOT INTENDED FOR BIDDING OR CONSTRUCTION PURPOSES.
DIANA DWORACZYK P.E. No. 63724 SOILS BOUNDARY MAP DES BY AW SCAt...E:
SEE BAR SCA1.E OR BY AW PROJECT NO. 15052,01 CHl( BY OD CJI NO. 1S05200l5R1 APP BY CO SHEET I Of I SH££TS DATE ISSUED: OJ-oa-20111 ncuRE No2. 2_ 1 _ 1
WCS\\FINAL\\ 180591 R190206_C1SF REPORT ADDENDUM A BERM BREACH ANALYSIS Cii REVISION 3 06 FEBRUARY 2019
c.
- cooK-JOVCE INC.
'I ENGINEERING AND CONSUL TING 812 WEST ELEVENTH 512-474-9097
ADDENDUM A BERM BREACH ANALYSIS FEBRUARY 2019 Prepared for:
Waste Control Specialists LLC P.O. Box 1129 Andrews, Texas 78714 Prepared by:
Cook-Joyce, Inc.
812 West 11th Street, Suite 205 Austin, Texas 78701 This report is issued for permitting or licensing purposes. It is not intended for bidding or WCSIFINAL 1180591 R190206_ADDENDUM A construction purposes <;'i _
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Diana Dworaczyk P.E. No. 63724 06 February 2019 TEXAS REGISTERED ENGINEERING FIRM F-883 REVISION 0 06 FEBRUARY 2019
Cii TABLE OF CONTENTS SECTION PAGE
1.0 INTRODUCTION
............................................................................................................... 1 2.0 WATERSHED DESCRIPTION AND MODEL................................................................... 1 3.0 BERM BREACH............................................................................................................... 1 WCS\\FI NAL \\ 18059\\
R190206_ADDENDUM A ii REVISION 0 06 FEBRUARY 2019
LIST OF FIGURES FIGURE A-1 DEVELOPED DRAINAGE AREA DITCHES APPENDIX APPENDIX A APPENDIX B WCS\\FINAL\\180591 R1 90206_ADDENDUM A LIST OF APPENDICES CALCULATIONS HEC-HMS OUTPUT iii Cii REVISION 0 06 FEBRUARY 2019
Cii
1.0 INTRODUCTION
This addendum presents the results of a hydrologic and hydraulic analysis for an unlikely berm breach of the proposed berm and ditch located just north of the protected area fence for the Centralized Interim Storage Facility (CISF). The same analysis methods, strategies and references that are found in the main part of the flood report are used in this analysis.
The diversion berms and collection ditches, A and Bas shown on Figure A-1, will divert surface water runoff from the area north and upgradient of the CISF. Collection ditches A and B drainage areas that will contribute runoff to the ditches and berms are delineated on Figure A-1. Collection Ditch A drainage area is 4.3 acres and Collection Ditch B drainage area is 62.2 acres. Collection Ditch B has the largest drainage area contributing surface water runoff to it by a substantial amount and will carry the largest flow. Therefore, only a berm breach in Collection Ditch B is analyzed since it will yield the greatest potential surface water flow to the storage pads.
2.0 WATERSHED DESCRIPTION AND MODEL Drainage Area Ditch B DA contains 62.2 acres and drains southeast toward the collection ditch and berm. Collection Ditch B drains to the east and ends several hundred feet past the northeast corner of the protected area fence. The soils in the area draining to Ditch B DA are the Jalmar-Pehnwell series and are classified as hydrologic group A/B as shown on Figure 2.2.1-1, Soils Boundary Map.
Curve number (CN) and time of concentration parameters are found in Addendum A, Appendix A, Calculations.
The Ditch B DA parameters are input into the HEC-HMS model to determine peak runoff rates for Collection Ditch B. The 100-year, 500-year and PMP peak discharges for Collection Ditch B are 60 cubic feet per second (CFS), 129 CFS and 251 CFS, respectively. HEC-HMS model setup and inputs are found on the CD in Appendix E of the main part of the report. Results of the HEC-HMS modeling for Collection Ditch B are found in Addendum A, Appendix B, HEC-HMS Output.
3.0 BERM BREACH Onsite surface water runoff will be mainly sheet flow off the sloped storage pads and the sloped areas in between the pads. The Collection Ditch B berm is 2.6 feet high and approximately 4 70 feet from the nearest storage pad at the northern side of the CISF as surface water flows, which is the Phase 8 storage pad. The worst-case for a berm breach will be when Collection Ditch B WCS\\FINAL\\18059\\
R190206_ADDENDUM A REVISION 0 06 FEBRUARY 2019
Cii has the greatest amount of surface water flowing in it and will be at the location where breach flow can still reach a storage pad.
The peak flow, 251 CFS, in Collection Ditch B is calculated by HEC-HMS at the analysis point depicted on Figure A-1. The analyzed berm breach location is approximately 800 feet upstream from the analysis point, yet the peak flow is conservatively assumed to flow in Collection Ditch B at that location. The berm breach location is depicted on Figure A-1.
Assumptions for the overland depth of flow adjacent to the Phase 8 storage pad from a berm breach include the following : the berm breach is large enough to release the entire PMP flow, even though Ditch B will still be flowing to the southeast; all of the breach flow will reach the storage pad, even though the pads sit above the surrounding area; and the berm breach flow will spread out from the breach at approximately 2:1 angles from the breach area as it returns to overland flow over the approximately 470 feet to the nearest pad.
The estimated depth of flow adjacent to the pad is approximately 3 inches. Overland depth of flow calculations are found in Addendum A, Appendix A, Calculations.
WCS\\FINAL\\180591 R190206_ADDENDUM A 2
REVISION 0 06 FEBRUARY 2019
WCS\\FINAL\\180591 R190206_ADDENDUM A FIGURE 3
Cii REVISION 0 06 FEBRUARY 2019
/;
I' S'.\\CAD\\WCS\\150S2 CISF Floodplain\\ 15052016 Fig A*l Developed Drainage Area Ditches dwg 2/6/2019 1:22:35 PM. 1:1 500 O
500
\\
(SCALE IN ml)
LEGEND
- -------* DRAINAGE AREA BOUNDARY LIMITS OF TOPOGRAPHIC SURVEY BY DALLAS AERIAL SURVEY 5-29-201 4 0
ANALYSIS POINT EXISTING MINOR CONTOUR
- 3490-EXISTING MAJOR CONTOUR PROPOSED MINOR CONTOUR
-3490-PROPOSED MAJOR CONTOUR 2
EXISTING TOPOGRAPHIC INFORMATION OUJi~\\~;l
. OF THE LIMITS SHOWN IS BASED ON A ELEVATION MODEL (DEM) PROVIDED BY THE TEXAS NATURAL RESOURCE INFORMATION SYSTEM (TNRIS).
REV. OAl[
c:
- caaK-JQYCE INC.
ENGINEERING AND CONs;i;.~~
~AU~~s~'i70~--
HVB & ¥19E CERTIFlED TEXAS RECISTEREO ENGINEERING MM F-MJ
WCS\\FINAL\\ 1 B059\\
R190206_ADDENDUM A APPENDICES Cii REVISION 0 06 FEBRUARY 2019
WCS\\FINAL\\18059\\
R190206_ADDENDUM A APPENDIX A CALCULATIONS Cii REVISION 0 06 FEBRUARY 2019
ADDENDUM A WCS - CISF DITCH B POST-DEVELOPMENT DRAINAGE AREA TIME OF CONCENTRATION wcs DES DD CHK 1/31/2019 SC 2/5/2019
Reference:
- 1. United States Department of Agriculture, Urban Hydrology for Small Watersheds TR-55, 1986
- 2. Reference Drawing: S:ICAD\\WCS\\1 5052 CISF Floodplain\\Engineering\\15052 - P Hydraulic Cales DD.dwg DITCH B Drainage Area A
62.2 (acres) 0.097 (sqmi)
Sheet Flow Manning's roughness coef.1 n
0.15 n/a Flow Length L
408 feet 2-year, 24-hour rainfall P2 2.5 inches Slope s
0.0098 ft/ft Travel time' Tt 0.76 hcurs 45.4 min.
Shallow Concentrated Flow Flow Length L
1060 feet Slope s
0.00710 fVft Surface (1 =paved or 2=unpaved) 2 n/a Velocity' V
1.36 ft/sec Travel time Tt 0.22 hours2.546296e-4 days <br />0.00611 hours <br />3.637566e-5 weeks <br />8.371e-6 months <br /> 12.99 min.
Manning's Equation Flow Length L
1383 feet Slope s
0.00500 ft/ft roughness" n
0.028 n/a Open Channel Bottom Width BW 4
feet Side Slopes (ft/ft. H:V) Rt.
H:V 3
feet Side Slopes (fVft. H :V) Lt.
H:V 3
feet Depth d
2 feet Flow Rate 0
111 cfs Velocity V
4.2 ft/sec Travel time Tt 0.09 hours1.041667e-4 days <br />0.0025 hours <br />1.488095e-5 weeks <br />3.4245e-6 months <br /> 5.49 min.
Total Travel Time T
1.06 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> T
63.90 min.
Lag Time (Tc*o.6)
Tlag 0.64 hours7.407407e-4 days <br />0.0178 hours <br />1.058201e-4 weeks <br />2.4352e-5 months <br /> Tlag 38.34 min.
Notes:
- 1. Manning's roughness coefficient taken from Table 3-1 Roughness coefficients (Manning's n) for sheet flow' - United States Department of Agriculture, Urban Hydrology for Small Watersheds TR-55, 1986
- 2. Equation 3-3, United States Department of Agriculture, Urban Hydrology for Small Watersheds TR-55, 1986
- 3. Figure 3-1, United States Department of Agriculture, Urban Hydrology for Small Watersheds TR-55, 1986
- 4. Reference Manning's 'n' calculations in APPDX C: POST-DEVELOPMENT HYDRAULIC CALCULATIONS S:\\Projects\\W - -Z:..WCS (Waste Control Specialists)ldraft\\18059 ISP - NRC Responses\\Engineering Checks\\Ditch B HEC\\R190204_TC.xls WCSIFINAL\\18059 R190206_ADDENDUM A APPA-1 REVISIONO 06 FEBRUARY 2019
WCS Job No. 18059 File: R190204_CURVE NO CURVE NUMBER ADDENDUM A WCS - CISF DITCH B POST-DEVELOPMENT CURVE NUMBER CALCULATIONS DES DD 2/4/2019 CHK SC 2/5/2019 Cii
Reference:
- 1. CISF Drainage Evaluation and Floodplain Analysis Fig. No. 2.2.1-1, Soils Boundary Map
- 2. Soil information taken from US Department Of Agriculture, Natural Resources Conservation Service Custom Soil Resource Report For Andrews County, Texas, And Lea County, New Mexico, dated December 22, 2015
- 3. Texas Engineering Technical Note, No. 21 0-18-TX5, Estimating Runoff for Conservation Practices, 1990 Drainage Area - Ditch B Cover Type & Hydrologic Condition Desert Shrub Poor A=
62.2 Acres Soil Type Hyd. Soil Group JPC B/A'"
0.097 sq mi CN" 77
' Taken from Table 2c of Texas Engineering Technical Note, Hydrology, No. 210-18-TXS, Estimating Runoff for Conservation Practices
" Taken from Table 3 ofTexas Engineering Technical Note, Hydrology, No. 210-18-TXS, Estimating Runoff for Conservation Practices
"'USDA Soil Survey indicates 46% A and 50% B. CN is conservatively calculated to be 100% B WCS\\FINAL\\18059 R190206_ADDENDUM A APP A-2 ARC I Adjustment" (60 Min.)
60 ARC Ill Adjustment" (60 Min.)
89 REVISION 0 06 FEBRUARY 2019
ADDENDUM A WCS - CISF BERM BREACH POST-DEVELOPMENT BERM BREACH OVERLAND DEPTH OF FLOW DES wcs DD 1/16/2019
Reference:
CHK SC 2/5/2019
- 1. Reference Drawing: S:\\CAD\\WCS\\15052 CISF Floodplain\\Engineering\\15052-P Hydraulic Cales PMP.dwg Dich B carries the largest flow.
Use the PMP peak flow in Ditch B to calculate the pad depth of flow.
Manning Equation
- Where, Manning Equation for Sheet Flow
- 1 49/ *R 2/3* t/2 v-n h
s v= velocity (ft/s) n= Manning's n Rh= hydraulic radius s= slope (ft/ft) q=
v*y= 1.49/n*/13*s112 Therefore
- Where, Max flow
- Where, Max depth at edge of pad
- Where, y= (q/(1.49/n*s1/2))3/s V= q/y q= unit discharge (ft2/s) v= velocity (ft/s) n= Manning's n y= depth s= slope (ft/ft) qMax= maximum unit discharge (ft2/s)
I= Rainfaill Intensity L= Length of flow Ymax= Maximum depth of flow (ft) qMax= Maximum unit discharge n= Manning's n s= slope (ft/ft)
Cii WCS\\FINAL\\18059 R190206_ADDENDUM A APP A-3 REVISION 0 06 FEBRUARY 2019
Cii Max velocity
- Where, Inputs qMax= maximum unit discharge (ft 2/ s)
Ymax= Maximum depth of flow (ft)
Omax =
251 cfs From HEC-HMS Ditch B Assumptions: Berm breach is large enough to release Ditch B PMP peak flow Calculation WCS\\FI NAL I 18059 R190206_ADDENDUM A s=
L=
n=
The flow spreads out at approx. 1:2 on each side from center of berm breach, Length of flow from berm breach to phase 8 pad= 470 ft., See Fig. A-1 Width offlow at phase 8 pad=
470 ft The peak flow reaches a pad and flows onto a pad.
qMax=
0.534043 ft 2/s I=
I= qmaJL 0.011 ft/ft 470 ft O.Q25 flow slope length of flow from berm breach to phase 8 pad, see Fig. A-1 Manning's n for gravel 0.001136 ft/sec Maxy= 0.228549 ft 2.7 in Maxv=
2.3 ft/s APP A-4 REVISION 0 06 FEBRUARY 2019
WCSIFINAL\\180591 R190206_ADDENDUM A APPENDIX B HEC-HMS OUTPUT Cii REVISION 0 06 FEBRUARY 2019
Project:
15052 - CISF Design Simulation Run: Collection Ditch B R Start of Run:
01Jan2016, 00:00 End of Run:
02Jan2016, 12:00 Compute Time: 04Feb2019, 16:25:04 Hydrologic Element Collection Ditch B R WC SIFI NAL I 18059 R190206_ADDENDUM A Drainage Area (Ml2) 0.097 Basin Model:
Collection Ditch B revised Meteorologic Model: 100 yr Control Specifications:Control 24 HR Storms Peak Discharge Time of Peak (CFS) 59.7 01Jan2016, 12:34 APP B-1 Volume (IN) 1.92 REVISION 0 06 FEBRUARY 2019
Project:
15052 - CISF Design Simulation Run: Collection Ditch BR 500 Yr Start of Run:
01Jan2016, 00:00 End of Run:
02Jan2016, 12:00 Compute Time: 04Feb2019, 16:26:45 Hydro logic Element Collection Ditch B R WCS\\FINAL\\18059 R190206_ADDENDUM A Drainage Area (Ml2) 0.097 Basin Model:
Collection Ditch B revised Meteorologic Model: 500 yr Control Specifications:Control 24 HR Storms Peak Discharge Time of Peak (CFS) 128.5 01Jan2016, 12:33 APP B-2 Volume (IN) 3.87 REVISION 0 06 FEBRUARY 2019
Project:
15052 - CISF Design Simulation Run: Collection Ditch BR PMP Start of Run:
01 Jan2016, 00:00 End of Run:
05Jan2016, 00:00 Compute Time: 04Feb2019, 16:26:51 Hydrologic Element Collection Ditch B R WCS\\FINAL\\18059 R190206_ADDENDUM A Drainage Area (Ml2) 0.097 Basin Model:
Collection Ditch B revised Meteorologic Model: PMP Distribution A Control Specifications:Control PMP Peak Discharge (CFS) 250.6 APP B-3 Time of Peak 03Jan2016, 06:01 Volume (IN) 33.47 REVISION 0 06 FEBRUARY 2019