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CRDC 1402-SY140401
engineers surveyors landscape architects Registered by the Texas Board of Professional Engineers; No. F-230 Registered by the Texas Board of Professional Surveyors No. 100116-00 Fort Worth Dallas Denton Sherman April 2014 WOODRIDGE CHANNEL IMPROVEMENTS CONCEPT STUDY TNP No. CPL 13314 EXISTING CONCEPT Woodridge Channel Improvements – Concept Study (MacArthur to 750’ west) EXECUTIVE SUMMARY Project Understanding & Location Project Understanding – The Woodridge channel has a history of flooding and poses chronic maintenance issues for the City. The purpose of this concept study is to identify improvement alternatives that could reduce or eliminate each of these issues. The focus of this study is to identify methods for completely enclosing the channel and provide Opinions of Probable Construction Cost (OPCC’s). This report is intended to aid the City’s evaluation of improvement alternatives and whether they are viable. Project Location – Woodridge Channel traverses the Woodridge Subdivision located southwest of the MacArthur/Sandy Lake Blvd. intersection. The subject portion of stream runs parallel to Sandy Lake Rd. along its south side, from MacArthur Blvd. to approximately 750’ (ft) west. Woodridge Channel is an unstudied stream per FEMA’s FIS (Panel: 48113C0155 J, Aug. 23, 2001) and the City-Wide Storm Water Management Study (Jan. 1991). Existing Conditions Analysis Methods – Peak discharges for this study were developed using a detailed HEC-HMS (v.3.5) model for the 2-, 5-, 10-, 25-, 50-, and 100-year storm (see Table 1). The watershed is considered to be in its ultimate developed condition for the purposes of this study. Hydraulic computations for this study are approximate in nature, and are based on aerial survey data, record drawings, and field observations. No topographic field survey was performed for this study. Results – The existing channel is trapezoidal in shape, vegetated, and generally has capacity to convey a 25-yr storm with 1’ (ft) of freeboard. The downstream end of the project is a 2-8x6 MBC at MacArthur Blvd. This culvert operates under inlet control and currently has a 25-yr capacity as well. Environmental Permitting – An environmental assessment was performed as part of this study which indicates the existing channel would be classified as Jurisdictional Waters of the U.S. by the United States Army Corp. of Engineers (USACE). Improvements to enclose or armor the channel will require an Individual Permit and associated mitigation in accordance with Section 404 (Clean Water Act). Onsite mitigation would not meet project goals, meaning purchasing mitigation credits from a USACE approved mitigation bank will likely be required. The anticipated cost for mitigation is $165,000. Table 1: Peak Discharge Summary (1) SCS Unit Hydrograph, TR-55 Tc's, Composite CN, Frequency Storm (TP-40/TP-35) (2) Node name in HEC-HMS model for key Design Points. See comments for location. (3) Record drawings for Woodridge Channel; in association with the Woodridge Subdivision Improvements The following paragraphs summarize the improvements necessary for each improvement alternative. The limits of improvements are shown on Exhibits 2 and 3 of Appendix A. Environmental mitigation costs are the same for all options and are reflected in the OPCC’s listed below. Option 1: Box Culvert Enclosure (100-YR Design) – This option entails constructing 750 LF of 2-9x6 MBC, and 110 LF of 1-6x6 RCB. The 1-6x6 is needed for additional capacity at MacArthur, and may be suitable for boring and jacking. The culvert system would be backfilled to create relatively flat ground 2 5 10 25 50 100 ac.25-yr/50-yr; (cfs)(cfs)(cfs)(cfs)(cfs)(cfs)(cfs) DP-1 274.4 827/925 441 636 830 1,044 1,211 1,391 @ MacArthur DP-2 295.1 971/1087 461 664 869 1,094 1,270 1,464 @ School DP-3 315.0 1169/1310 478 689 902 1,140 1,329 1,531 @ Denton Creek Node ID(2) Area QDESIGN Woodridge Plans(3) 100-Yr Existing1 ( = Ultimate) Comments Woodridge Channel Improvements – Concept Study (MacArthur to 750’ west) along Sand Lake Rd., making it suitable for a linear park. The anticipated construction cost is $1,700,000 (rounded), including environmental mitigation. No property acquisition is anticipated. Option 2: Con/Span Enclosure (100-YR Design) – This option entails constructing 750 LF of 25’x6’ Con/Span (bridge structure), and 110 LF of 1-6x6 RCB. The 1-6x6 is needed for additional capacity at MacArthur, and may be suitable for boring and jacking. The Con/Span system would be backfilled to create relatively flat ground along Sand Lake Rd., making it suitable for a linear park. The anticipated construction cost is $2,200,000, including environmental mitigation. No property acquisition is anticipated. Table 2: Improvement Alternative Summary (1) The MacArthur culvert has 25-yr capacity with freeboard and 50-yr capacity with no freeboard. Conclusion The subject reach of Woodridge Channel is undersized and requires chronic maintenance. Each one of the options presented above will address these concerns by: providing 100-yr design capacity, effectively eliminating the need for channel maintenance, and enhancing the aesthetic of the Sandy Lake Rd. corridor. Option 1 (Box Culvert) is anticipated to provide a significant cost savings and possibly a shorter construction time. The cost of Option 2 (Con/Span) is significantly higher, but could be reduced if soil conditions permit less foundation work than anticipated. The Con/Span offers more room for maintenance access and better aesthetic at the opening. Existing Vegetated Trapezoid Channel 25(1)N/A Option 1 Box Culvert Enclosure 100 $ 1.7 M Option 2 Con/Span Enclosure 100 $ 2.2 M Improvement Alternative Description Construction CostDesign Storm Concept Drainage Study for Woodridge Channel Prepared For: City of Coppell 265 Parkway Avenue Coppell, TX 75019 Prepared By: Teague Nall and Perkins, Inc. 1100 Macon Street Fort Worth, TX 76102 April 2014 Woodridge Channel Improvements – Concept Study (MacArthur to 750’ west) Fort Worth1100 Macon StreetFort Worth, Texas 76102817.336.5773 Dallas17304 Preston Road, Suite 1340Dallas, Texas 75252214.461.9867 Denton1517 Centre Place Drive, Suite 320Denton, Texas 76205940.383.4177 Sherman200 North Travis Street, Suite 500Sherman, Texas 75090903.870.1089 Registered by the Texas Board of Professional Engineers, Firm No. F-230 Registered by the Texas Board of Professional Surveyors, Firm No. 100116-00 Contents Project Understanding ......................................................................................................... 1 Project Location & Background ........................................................................................... 2 Hydrology ............................................................................................................................ 2 Existing Conditions .............................................................................................................. 2 Hydrologic Parameter Methodologies ................................................................................... 2 Hydraulics ........................................................................................................................... 3 Summary of Analysis Methods .............................................................................................. 3 Improvement Alternatives ..................................................................................................... 4 Conclusion .......................................................................................................................... 4 Appendices APPENDIX A – EXHIBITS o EXHIBIT 1: DRAINAGE AREA MAP o EXHIBIT 2: OPTION 1 – BOX CULVERT ENCLOSURE o EXHIBIT 3: OPTION 2 – CON/SPAN ENCLOSURE APPENDIX B – HYDROLOGIC DATA o TIME OF CONCENTRATION (Tc) COMPUTATIONS o CN CALCULATIONS o HEC-HMS INPUT/OUTPUT APPENDIX C – HYDRAULIC DATA O CULVERTMASTER REPORT O CONTECH BRIDGE TOOL REPORT (CON/SPAN) O STORMCAD REPORT APPENDIX D – ENVIRONMENTAL ASSESSMENT (excerpt only) APPENDIX E – OPNIION’S OF PROBABLE CONSTRUCTION COST (OPCC) APPENDIX F – COMPACT DISK o DRAINAGE STUDY REPORT (PDF) o HEC-HMS DIGITAL MODEL o HYDRAULIC MODELS o RECORD DRAWINGS o SHAPEFILES o ENVIRONMENTAL ASSESSMENT REPORT (PDF, complete) o PANORAMIC IMAGES & RENDERING Woodridge Channel Improvements – Concept Study (MacArthur to 750’ west) Project Understanding Teague Nall and Perkins, Inc. (TNP) was contracted by the City of Coppell to evaluate concept level solutions to mitigate flood hazards and maintenance issues along a portion of Woodridge Channel. The focus of this study is to identify methods for completely enclosing the channel and provide Opinions of Probable Construction Cost (OPCC’s). This report is intended to aid the City’s evaluation of improvement alternatives and whether they are viable. Project Location & Background Woodridge Channel traverses the Woodridge Subdivision located southwest of the MacArthur/Sandy Lake Blvd. intersection. The subject portion of stream runs parallel to Sandy Lake Rd. along its south side, from MacArthur Blvd. to approximately 750’ (ft) west. Woodridge Channel is an unstudied stream per FEMA’s FIS (Panel: 48113C0155 J, Aug. 23, 2001) and the City-Wide Storm Water Management Study (Jan. 1991). Hydrology Existing Conditions A hydrologic analysis has been prepared as part of this study. Hydrographs and peak discharges were developed using HEC-HMS (v.3.5), with parameters developed as described below. A summary of the 100-year peak discharges is listed in Table 1. A digital copy of the model is included in Appendix E. Hydrologic Parameter Methodologies Area – Drainage basins were delineated using 2’ (ft) interval contours (provided by City), and then adjusted based on record drawings for Woodridge Subdivision and field verification. Four (4) sub-basins were delineated to properly account for watershed timing and to develop peak discharges at key design points along the stream (See Exhibit 1). Time of Concentration (Tc) – The longest flow path for each sub-basin was delineated based on topography, aerial photos, record drawings, and City GIS data. Actual flow times were computed using the TR-55 methodology; consisting of sheet flow, shallow flow, pipe flow, and channel flow. Composite Curve Number – Composite curve numbers were weighted by area based on hydrologic soil type and landuse. In general the curve number values used reflect ¼ acre residential lots (SCS TR-55, Table 2.2). The following values were used: Soil Type A (61), B (75), C (83), D (87). Percent Impervious – Composite curve numbers were weighted based on area and landuse. Impervious surfaces are accounted for by the composite curve numbers, therefore the separate impervious value field in the model is zero for all sub-basins. Soil Type – Drainage basins were overlaid on the NRCS soil survey for Dallas County for the purpose of calculating the percentage of each hydrologic soil group (A, B, C, and D). Routing – The Muskingum Cunge method was used for channel routing. By defining the channel shape, roughness, slope, and length, the HMS computations are able to account for timing delay of the flood wave, as well as approximate valley storage and associated peak attenuation. Computation summaries for the above parameters are provided in Appendix B. Woodridge Channel Improvements – Concept Study (MacArthur to 750’ west) Parameter tabulations are included in Appendix B and a summary of hydrologic parameters is provided in Table 1, below. A summary of the resulting 100-year peak discharges is provided in Table 2 and a digital copy of the HEC-HMS model is included in Appendix E (compact disk). Table 1: Hydrologic Parameter Summary Table 2: Peak Discharge Summary 1 SCS Unit Hydrograph, TR-55 Tc's, Composite CN, Frequency Storm (TP-40/TP-35) Hydraulics Due to the conceptual nature of this study, . Digital models and model summaries (HEC-RAS, and PDF’s) are provided in Appendix C (compact disk). Summary of Analysis Methods Existing Conditions – FlowMaster (Bentley Systems, Inc.) was used to calculate normal depth for the channel. CulvertMaster (Bentley Systems, Inc.) was used to calculate culvert headwater. CulvertMaster utilizes FHWA culvert hydraulic equations to determine Inlet/Outlet control, mannings equation for normal depth tailwater, and the broad crested weir equation for roadway overtopping. The existing 4-10x8 driveway culverts have more capacity than the bounding earthen channel and therefore are governed by outlet control. The 2-8x6 MacArthur culverts operate in inlet control and have approximately 1,050 cfs capacity with 1’ (ft) of freeboard to the lowest adjacent top of curb. Option 1, Box Culvert Enclosure – This scenario was analyzed using the storm drain modeling software, StormCAD® (Bentley Systems, Inc.). Conduit links were used to represent each unique section (i.e. box shape, size, slope, number of barrels, etc…). Hydraulic grade lines were calculated for the entire project reach, with headlosses at transition points. Con/Span Channel with Existing Culverts – The existing culverts were analyzed using CulvertMaster. The Con/Span segments between the existing culverts were analyzed with the Area Tc Lag (ac)(min)(min) DA-1 194.6 84.6 0 25 15 DA-2 79.8 76.4 0 20 12 DA-3 20.7 83.4 0 10 6 DA-4 19.9 84.2 0 10 6 Existing CN % Imp. Area ID 2 5 10 25 50 100 ac.(cfs)(cfs)(cfs)(cfs)(cfs)(cfs)(cfs) DA-1 194.6 --350 497 637 792 910 1,038 DA-2 79.8 --101 158 215 280 330 385 DA-3 20.7 --48 71 89 111 127 144 DA-4 19.9 --48 70 88 109 124 140 DP-1 274.4 827/925 441 636 830 1,044 1,211 1,391 @ MacArthur DP-2 295.1 971/1087 461 664 869 1,094 1,270 1,464 @ Universal Academy DP-3 315.0 1169/1310 478 689 902 1,140 1,329 1,531 @ Denton Creek 100-Yr Existing1 ( = Ultimate)Node ID Area Comments QDESIGN Woodridge Plans Woodridge Channel Improvements – Concept Study (MacArthur to 750’ west) BSH-Tool using downstream CulvertMaster headwater as the controlling tailwater. The 2-8x6 MBC and proposed 1-6’x6’ RCB at MacArthur were calculated using CulvertMaster assuming one (1) foot of freeboard to the approximate back of curb elevation of 454.0. Improvement Alternatives Option 1: Box Culvert Enclosure (100-YR Design) – This option entails constructing 750 LF of 2- 9x6 MBC, and 110 LF of 1-6x6 RCB. The 1-6x6 is needed for additional capacity at MacArthur, and may be suitable for boring and jacking. The culvert system would be backfilled to create relatively flat ground along Sand Lake Rd., making it suitable for a linear park. The anticipated construction cost is $1,700,000 (rounded), including environmental mitigation. No property acquisition is anticipated. Option 2: Con/Span Enclosure (100-YR Design) – This option entails constructing 750 LF of 25’x6’ Con/Span (bridge structure), and 110 LF of 1-6x6 RCB. The 1-6x6 is needed for additional capacity at MacArthur, and may be suitable for boring and jacking. The Con/Span system would be backfilled to create relatively flat ground along Sand Lake Rd., making it suitable for a linear park. The anticipated construction cost is $2,200,000, including environmental mitigation. No property acquisition is anticipated. Table 2: Improvement Alternative Summary (1) The MacArthur culvert has 25-yr capacity with freeboard and 50-yr capacity with no freeboard. Conclusion The subject reach of Woodridge Channel is undersized and requires chronic maintenance. Each one of the options presented above will address these concerns by: providing 100-yr design capacity, effectively eliminating the need for channel maintenance, and enhancing the aesthetic of the Sandy Lake Rd. corridor. Option 1 (Box Culvert) is anticipated to provide a significant cost savings and possibly a shorter construction time. The cost of Option 2 (Con/Span) is significantly higher, but could be reduced if soil conditions permit less foundation work than anticipated. The Con/Span offers more room for maintenance access and better aesthetic at the opening. Existing Vegetated Trapezoid Channel 25(1)N/A Option 1 Box Culvert Enclosure 100 $ 1.7 M Option 2 Con/Span Enclosure 100 $ 2.2 M Improvement Alternative Description Construction CostDesign Storm APPENDIX A – EXHIBITS o EXHIBIT 1: DRAINAGE AREA MAP o EXHIBIT 2: OPTION 1 – BOX CULVERT ENCLOSURE o EXHIBIT 3: OPTION 2 – CON/SPAN ENCLOSURE %, %,%, Wo o d r i d g e Su b d i v i s i o n Co p p e l l M i d d l e Sc h o o l Denton Creek Woodridge Channel Un i v e r s a l Ac a d e m y DA - 1 19 4 . 6 A C DA - 2 79 . 8 A C DA - 3 20 . 7 A C DA-4 19.9 ACDP-2 DP-3 DP - 1 SANDY LAKE RD JOHNSON LN MA C A R TH U R BLVD FALCON LN Starleaf St PINYON LN HILL DR R I V E R C H A S E D R ASPENWAY DR MAPLELEAF LN BARCLAY AVE TIMBER RIDGE LN H A W K L N TUPELO DR EAGLE DR CONDOR DR SUGARBERRY DR REDCEDAR WAY DR CREEKSIDE LN ORIOLE LN RO BI N LN BETH EL SCHOOL RD QUAIL LN FALLS RD CHERRYBARK DR VILLAWOOD LN SPRINGOAK LN W I L L E T D R SPAR RO W LN BRADFORD DR ROLLING BROOK LN FINCH LN SWALLOW DR L O N G M E A D O W D R CARDINAL LN BUTTE RNUT DR R E D WIN G D R SAMUEL BLVD GLADE POINT DR PEPPERWOOD ST MEADOWLA RK LN DEANN DR LANS DOWNE ST MEADOW RUN LA G U N A D R KINGSMILL CTPEBBLE CREEK DR MESQUITEWOOD DR STONECREST DR STARL EAF ST V I L L A G E P K W Y COLONIAL DR BETHEL SCHOOL CT B R I T T A N Y D R MEADOWGLEN CIR K IM B L E KO U R T PINYON DR FOUN T AI N DR O L D Y O R K R DWELLINGTON R D DOVE CIR DUNLIN LN LANSDOWNE CIR GRAPEVINE CREEK DR INDEPENDENCE DR BILTMORE CT S H A D O W C R E S T L N FALCON CT R I V E R V I E W D R S U N R I S E D R CASCADE WAY HEMLOCK CT H A W K C T FPREST CPVE ELMHILL CT ELMVA L E CT JENNINGS CT M A C A R T H UR BL V D N 0 5 0 0 1 , 0 0 0 25 0 1 i n c h = 5 0 0 f e e t Legend %,Design Point Drainage Area Minor Contour (2ft)Major Contour (10ft)City of Coppell, TX Dr a i n a g e A r e a M a p Wo o d r i d g e C h a n n e l I m p r o v e m e n t s - D r ainage Study & Conceptual DesignEXHIBIT 1AreaTcLag(ac)(min)(min)DA‐1194.684.602515 DA‐279.876.402012 DA‐320.783.40106 DA‐419.984.20106ExistingCN% Imp.Area ID 25102550100 ac . 2 5 ‐yr / 5 0 ‐yr ; (c f s ) ( c f s ) ( c f s ) ( c f s ) ( c f s ) ( c f s ) ( c f s ) DP ‐1 2 7 4 . 4 8 2 7 / 9 2 5 4 4 1 6 3 6 8 3 0 1 , 0 4 4 1 , 2 1 1 1 , 3 9 1 @ MacArthur DP ‐ 2 2 9 5 . 1 9 7 1 / 1 0 8 7 4 6 1 6 6 4 8 6 9 1 , 0 9 4 1 , 2 7 0 1 , 4 6 4 @ School DP ‐ 3 3 1 5 . 0 1 1 6 9 / 1 3 1 0 4 7 8 6 8 9 9 0 2 1 , 1 4 0 1 , 3 2 9 1 , 5 3 1 @ Denton Creek (1 ) SC S Un i t Hy d r o g r a p h , TR ‐ 55 Tc ' s , Composite CN, Frequency Storm (TP‐40/TP‐35) (2 ) No d e na m e in HE C ‐ HM S mo d e l fo r key Design Points; see Comments for location. No d e ID (2 ) Ar e a QDE S I G N Wo o d r i d g e Pl a n s (3)100‐Yr Existing1 ( = Ultimate)Comments Sandy Lake Rd. S M a c A r t h u r B l v d Pinyon Ln. N 0 100 20050 1 inch = 100 feet Legend Exist Drainage Esmt Prop Box Culvert City of Coppell, TX Option 1 - Box Culvert Enclosure Woodridge Channel Improvements - Concept Drainage Study EXHIBIT2 Sandy Lake Rd. S M a c A r t h u r B l v d Pinyon Ln. Mapleleaf Ln N 0 100 20050 1 inch = 100 feet Legend Exist Drainage Esmt Prop Con Span City of Coppell, TX Option 2 - Con/Span Enclosure Woodridge Channel Improvements - Concept Drainage Study EXHIBIT3 APPENDIX B – HYDROLOGIC DATA o TIME OF CONCENTRATION (Tc) COMPUTATIONS o CN CALCULATIONS o HEC-HMS INPUT/OUTPUT Woodridge Channel Time of Concentration Calculations Based on NRCS Publication "TR55 - Urban Hydrology for Small Watersheds" Length (ft)'n' value Slope (ft/ft) P2 (in) 2- yr,24hr Veloc (fps) Travel Time (min) Total Sheet Flow Time (min) Length Paved (y/n) Slope (ft/ft) Veloc (fps) Travel Time (min) Total Shallow Flow Time (min) Length (ft) Pipe Dia (in)'n' value Slope (ft/ft) Veloc (fps) Travel Time (min) Total Pipe Flow Time (min) Length (ft) Bottom Width (ft) Depth of Flow (ft) SS (H:V)'n' value Slope (ft/ft) Veloc (fps) Travel Time (min) Total Channel Flow Time (min) Total Length (ft) Time of Conc (min) SCS Lagtime (min) Avg Veloc (ft/sec) 0.00 0.00 0.00 DA-1 70 0.24 0.011 3.95 0.10 12.26 12.26 1150 y 0.015 2.49 7.70 7.70 900 36 0.015 0.006 6.35 2.36 2.36 1380 8.00 2.88 2.88 3500 25.20 15.12 2.31 DA-2 75 0.24 0.012 3.95 0.10 12.52 12.52 580 y 0.015 2.49 3.88 3.88 1600 48 0.015 0.005 7.02 3.80 3.80 2255 20.20 12.12 1.86 DA-3 80 0.02 0.005 3.95 0.52 2.56 2.56 290 y 0.005 1.44 3.36 3.36 280 24 0.015 0.005 4.42 1.05 1.05 900 5.50 2.73 2.73 1550 9.71 5.82 2.66 DA-4 80 0.013 0.01 3.95 0.97 1.38 1.38 800 y 0.01 2.03 6.56 6.56 160 24 0.015 0.007 5.24 0.51 0.51 670 6.00 1.86 1.86 1710 10.31 6.18 2.77 Channel Flow Component Final Tc Calculation Basin Sheet Flow Component Shallow Flow Component Pipe Flow Component HEC-HMS Basin Data (Existing) Page 1 of 5 Basin: Exist_Wtd_CN Last Modified Date: 21 February 2014 Last Modified Time: 18:37:09 Version: 3.5 Filepath Separator: \ Unit System: English Missing Flow To Zero: No Enable Flow Ratio: No Allow Blending: No Compute Local Flow At Junctions: No Enable Sediment Routing: No Enable Quality Routing: No End: Subbasin: DA-1 Description: Headwaters of woodridge channel. Canvas X: 2438578.2395267426 Canvas Y: 7037248.462996644 HEC-HMS Basin Data (Existing) Page 2 of 5 Area: 0.3041 Downstream: R1 Canopy: None Surface: None LossRate: SCS Curve Number: 84.6 Transform: SCS Lag: 15 Unitgraph Type: STANDARD Baseflow: None End: Reach: R1 Canvas X: 2440876.8495172537 Canvas Y: 7039003.296123928 From Canvas X: 2438947.0616568234 From Canvas Y: 7038480.66420396 Downstream: J1 Route: Muskingum Cunge Channel: Trapezoid Length: 2200 Energy Slope: 0.006 Width: 6 Side Slope: 3 Mannings n: 0.025 Use Variable Time Step: No Invert Elevation: 443 Channel Loss: None End: Subbasin: DA-2 Description: Upstream of MacArther Canvas X: 2440548.0849942206 Canvas Y: 7038287.870817781 Area: 0.1247 Downstream: J1 Canopy: None Surface: None LossRate: SCS Curve Number: 76.4 Transform: SCS Lag: 12 HEC-HMS Basin Data (Existing) Page 3 of 5 Unitgraph Type: STANDARD Baseflow: None End: Junction: J1 Description: Combine 1 & 2 Canvas X: 2440876.8495172537 Canvas Y: 7039003.296123928 Downstream: R2 End: Reach: R2 Canvas X: 2441888.795685761 Canvas Y: 7039009.700846514 From Canvas X: 2440876.8495172537 From Canvas Y: 7039003.296123928 Downstream: J2 Route: Muskingum Cunge Channel: Trapezoid Length: 1070 Energy Slope: 0.006 Width: 10 Side Slope: 3 Mannings n: 0.035 Use Variable Time Step: No Invert Elevation: 437 Channel Loss: None End: Subbasin: DA-3 Description: Downstream of MacArther Canvas X: 2441127.7123882077 Canvas Y: 7038766.321388265 Area: 0.0323 Downstream: J2 Canopy: None Surface: None LossRate: SCS Curve Number: 83.4 Transform: SCS Lag: 6 Unitgraph Type: STANDARD HEC-HMS Basin Data (Existing) Page 4 of 5 Baseflow: None End: Junction: J2 Description: Combine 3 Canvas X: 2441888.795685761 Canvas Y: 7039009.700846514 Downstream: R3 End: Reach: R3 Canvas X: 2442847.3804024123 Canvas Y: 7038446.0852589905 From Canvas X: 2441888.795685761 From Canvas Y: 7039009.700846514 Downstream: J3 Route: Muskingum Cunge Channel: Trapezoid Length: 1060 Energy Slope: 0.006 Width: 20 Side Slope: 3 Mannings n: 0.035 Use Variable Time Step: No Invert Elevation: 433 Channel Loss: None End: Subbasin: DA-4 Description: At Denton Creek Canvas X: 2442251.7412019614 Canvas Y: 7039064.140988491 Area: 0.0311 Downstream: J3 Canopy: None Surface: None LossRate: SCS Curve Number: 84.2 Transform: SCS Lag: 6 Unitgraph Type: STANDARD Baseflow: None HEC-HMS Basin Data (Existing) Page 5 of 5 End: Junction: J3 Description: Combine 4 Canvas X: 2442847.3804024123 Canvas Y: 7038446.0852589905 End: Basin Schematic Properties: Last View N: 7039581.271739131 Last View S: 7035929.097826087 Last View W: 2436750.25 Last View E: 2442880.684782609 Maximum View N: 7039999.75 Maximum View S: 7029999.75 Maximum View W: 2430000.25 Maximum View E: 2448000.25 Extent Method: Maps Buffer: 0 Draw Icons: Yes Draw Icon Labels: Yes Draw Map Objects: No Draw Gridlines: No Draw Flow Direction: No Fix Element Locations: No Fix Hydrologic Order: No Map: hec.map.mrsid.MrSidMap Map File Name: O:\PROJECTS\CPL13314\engdata\H-H\GIS\aerials\j_09d.sid Minimum Scale: -2147483648 Maximum Scale: 2147483647 Map Shown: Yes Map: hec.map.aishape.AiShapeMap Map File Name: O:\PROJECTS\CPL13314\engdata\H-H\GIS\shape\DA.shp Minimum Scale: -2147483648 Maximum Scale: 2147483647 Map Shown: Yes End: Curve Number Calculations A B C D DA-1 0.2 0.8 84.6 DA-2 0.2 0.45 0.35 76.4 DA-3 0.3 0.7 83.4 DA-4 0.7 0.3 84.2 % Area By Soil TypeArea ID Weighted CN APPENDIX C – HYDRAULIC DATA O CULVERTMASTER REPORT O CONTECH BRDIGE TOOL REPORT (CON/SPAN) O STORMCAD REPORT Culvert Designer/Analyzer Report Prop_MacArthur_1-6x6 Title: Woodridge Channel - Concept Study o:\projects\cpl13314\engdata\h-h\woodridge_cv.cvm 04/01/14 10:44:03 AM Teague Nall & Perkins Inc © Bentley Systems, Inc. Haestad Methods Solution Center Watertown, CT 06795 USA +1-203-755-1666 Project Engineer: Kyle Dykes CulvertMaster v3.3 [03.03.00.04] Page 1 of 3 Analysis Component Storm EventDesignDischarge1,044.00cfs Peak Discharge Method: User-Specified Design Discharge1,044.00cfsCheck Discharge1,211.00cfs Tailwater properties: Trapezoidal Channel Tailwater conditions for Design Storm. Discharge1,044.00cfsBottom Elevation443.40ft Depth5.82ftVelocity6.53ft/s Name Description Discharge HW Elev. Velocity Culvert-11-6 x 6 ft Box517.27 cfs455.44 ft14.37 ft/s WeirRoadway (Constant Elevation)527.01 cfs455.45 ftN/A Total----------------1,044.28 cfs455.44 ftN/A Culvert Designer/Analyzer Report Prop_MacArthur_1-6x6 Title: Woodridge Channel - Concept Study o:\projects\cpl13314\engdata\h-h\woodridge_cv.cvm 04/01/14 10:44:03 AM Teague Nall & Perkins Inc © Bentley Systems, Inc. Haestad Methods Solution Center Watertown, CT 06795 USA +1-203-755-1666 Project Engineer: Kyle Dykes CulvertMaster v3.3 [03.03.00.04] Page 2 of 3 Component:Culvert-1 Culvert Summary Computed Headwater Eleva 455.44ftDischarge517.27cfs Inlet Control HW Elev.455.44ftTailwater Elevation449.22ft Outlet Control HW Elev.454.26ftControl TypeInlet Control Headwater Depth/Height1.90 Grades Upstream Invert444.06ftDownstream Invert443.41ft Length110.00ftConstructed Slope0.006000ft/ft Hydraulic Profile ProfilePressureProfileDepth, Downstream6.00ft Slope TypeN/ANormal DepthN/Aft Flow RegimeN/ACritical Depth6.00ft Velocity Downstream14.37ft/sCritical Slope0.009203ft/ft Section Section ShapeBoxMannings Coefficient0.013 Section MaterialConcreteSpan6.00ft Section Size6 x 6 ftRise6.00ft Number Sections1 Outlet Control Properties Outlet Control HW Elev.454.26ftUpstream Velocity Head3.21ft Ke0.20Entrance Loss0.64ft Inlet Control Properties Inlet Control HW Elev.455.44ftFlow ControlSubmerged Inlet Type90° headwall w 45° bevelsArea Full36.0ft² K0.49500HDS 5 Chart10 M0.66700HDS 5 Scale2 C0.03140Equation Form2 Y0.82000 Culvert Designer/Analyzer Report Prop_MacArthur_1-6x6 Title: Woodridge Channel - Concept Study o:\projects\cpl13314\engdata\h-h\woodridge_cv.cvm 04/01/14 10:44:03 AM Teague Nall & Perkins Inc © Bentley Systems, Inc. Haestad Methods Solution Center Watertown, CT 06795 USA +1-203-755-1666 Project Engineer: Kyle Dykes CulvertMaster v3.3 [03.03.00.04] Page 3 of 3 Component:Weir Hydraulic Component(s): Roadway (Constant Elevation) Discharge527.01cfsAllowable HW Elevation455.45ft Roadway Width90.00ftOvertopping Coefficient3.03US Length100.00ftCrest Elevation454.00ft Headwater Elevation455.44ftDischarge Coefficient (Cr)3.03 Submergence Factor (Kt)1.00 Sta (ft)Elev. (ft) 0.00454.00 100.00454.00 Culvert Designer/Analyzer Report Exist_MacA_2-8x6 Title: Woodridge Channel - Concept Study o:\projects\cpl13314\engdata\h-h\woodridge_cv.cvm 04/01/14 10:54:12 AM Teague Nall & Perkins Inc © Bentley Systems, Inc. Haestad Methods Solution Center Watertown, CT 06795 USA +1-203-755-1666 Project Engineer: Kyle Dykes CulvertMaster v3.3 [03.03.00.04] Page 1 of 3 Analysis Component Storm EventDesignDischarge1,044.00cfs Peak Discharge Method: User-Specified Design Discharge1,044.00cfsCheck Discharge1,211.00cfs Tailwater properties: Trapezoidal Channel Tailwater conditions for Design Storm. Discharge1,044.00cfsBottom Elevation443.40ft Depth5.82ftVelocity6.53ft/s Name Description Discharge HW Elev. Velocity Culvert-12-8 x 6 ft Box1,044.07 cfs452.68 ft14.20 ft/s WeirRoadway (Constant Elevation)0.00 cfs452.68 ftN/A Total----------------1,044.07 cfs452.68 ftN/A Culvert Designer/Analyzer Report Exist_MacA_2-8x6 Title: Woodridge Channel - Concept Study o:\projects\cpl13314\engdata\h-h\woodridge_cv.cvm 04/01/14 10:54:12 AM Teague Nall & Perkins Inc © Bentley Systems, Inc. Haestad Methods Solution Center Watertown, CT 06795 USA +1-203-755-1666 Project Engineer: Kyle Dykes CulvertMaster v3.3 [03.03.00.04] Page 2 of 3 Component:Culvert-1 Culvert Summary Computed Headwater Eleva 452.68ftDischarge1,044.07cfs Inlet Control HW Elev.452.68ftTailwater Elevation449.22ft Outlet Control HW Elev.452.21ftControl TypeInlet Control Headwater Depth/Height1.44 Grades Upstream Invert444.06ftDownstream Invert443.41ft Length110.00ftConstructed Slope0.006000ft/ft Hydraulic Profile ProfileCompositeS1S2Depth, Downstream4.59ft Slope TypeSteepNormal Depth4.48ft Flow RegimeN/ACritical Depth5.10ft Velocity Downstream14.20ft/sCritical Slope0.004279ft/ft Section Section ShapeBoxMannings Coefficient0.013 Section MaterialConcreteSpan8.00ft Section Size8 x 6 ftRise6.00ft Number Sections2 Outlet Control Properties Outlet Control HW Elev.452.21ftUpstream Velocity Head2.55ft Ke0.20Entrance Loss0.51ft Inlet Control Properties Inlet Control HW Elev.452.68ftFlow ControlSubmerged Inlet Type90° headwall w 45° bevelsArea Full96.0ft² K0.49500HDS 5 Chart10 M0.66700HDS 5 Scale2 C0.03140Equation Form2 Y0.82000 Culvert Designer/Analyzer Report Exist_MacA_2-8x6 Title: Woodridge Channel - Concept Study o:\projects\cpl13314\engdata\h-h\woodridge_cv.cvm 04/01/14 10:54:12 AM Teague Nall & Perkins Inc © Bentley Systems, Inc. Haestad Methods Solution Center Watertown, CT 06795 USA +1-203-755-1666 Project Engineer: Kyle Dykes CulvertMaster v3.3 [03.03.00.04] Page 3 of 3 Component:Weir Hydraulic Component(s): Roadway (Constant Elevation) Discharge0.00cfsAllowable HW Elevation452.68ft Roadway Width90.00ftOvertopping Coefficient2.90US Length100.00ftCrest Elevation454.00ft Headwater ElevationN/AftDischarge Coefficient (Cr)2.90 Submergence Factor (Kt)1.00 Sta (ft)Elev. (ft) 0.00454.00 100.00454.00 CONTECH Bridge Solutions Inc. Version: 4.0.1 Date: 4/1/2014 Time: 11:53:23 AM Culvert Report Project Name: O:\PROJECTS\CPL13314\engdata\H-H\Hydraulics\Contech_Bridge_Tool_Calcs.CSS Total Discharge: 1391.00 Cfs Tailwater Elevation: 452.45 ft Physical Data for C-Span 29 _________________________________________________________________________________ Culvert Type: CON/SPAN(TM) Culvert Span: 24.00 ft Culvert Rise: 6.00 ft Culvert Area: 118.26 ft^2 Culvert Upstream Elevation: 448.60 ft Culvert Downstream Elevation: 444.41 ft Culvert Length: 750.00 ft Culvert Slope: 0.006 Number of Barrels: 1 Entrance Condition: Extended WW Inlet Control Regression Coefficients: K = 0.4460 M = 0.6670 c = 0.0270 Y = 0.6760 Outlet Control Parameters: Manning Roughness Coefficient: 0.013 Entrance Loss Coefficient: 0.50 Hydraulic Results _________________________________________________________________________________ Culvert Discharge: 1391.00 Cfs Governing Headwater Elevation: 458.46 ft Inlet Control Headwater Elevation: 7.77 ft Outlet Control Headwater Elevation: 9.86 ft Culvert Normal Depth: 3.64 ft Culvert Critical Depth: 4.46 ft Culvert Entrance Loss: 1.07 ft Culvert Friction Loss: 2.79 ft Culvert Exit Loss: 2.15 ft Culvert Exit Velocity: 11.76 ft/sec Pier Debris Width: 0.00 ft Inlet Control Condition: Submerged Inlet Outlet Control Condition: Full Culvert Flow Conduit Detailed Report: Ex_2-8x6 Scenario Summary 1ID BaseLabel Notes Base Active TopologyActive Topology Base PhysicalPhysical Base HeadlossHeadloss Base Boundary ConditionBoundary Condition Base Rainfall RunoffRainfall Runoff Base HydrologicHydrologic Base DesignDesign Base System FlowsSystem Flows Base User Data ExtensionsUser Data Extensions Base Calculation Options Gradually Varied Flow Solver Calculation Options Pipe Characteristics OF-2Start Node User Defined ConduitConduit Type MH-12Stop Node Box PipeConduit Shape ft109.0Length (Unified)ConcreteMaterial ft/ft-0.006Slope 0.015Manning's n 2Number of Barrels Box Pipe - 96.0 x 72.0 in Conduit Description Hydraulic Summary ft³/s1,009Flow Composite S1 S2Profile Description ft³/s-1,052Capacity (Full Flow)ft-0.07Headloss ft³/s-2,061Excess Capacity (Full Flow) ft/s12.66Velocity (In) ft³/s-1,052Capacity (Design)ft/s11.06Velocity (Out) ft³/s-2,061Excess Capacity (Design) ft/s12.93Velocity (Average) Page 1 of 227 Siemon Company Drive Suite 200 W Watertown, CT 06795 USA +1-203-755-1666 4/1/2014 Bentley StormCAD V8i (SELECTseries 1) [08.11.00.44]Bentley Systems, Inc. Haestad Methods Solution CenterWoodridge.stc Conduit Detailed Report: Ex_2-8x6 EGL (ft) Hydraulic Grade (ft) Depth (ft) Cover (ft) Crown (ft) Ground (ft) Invert (ft) 451.01449.115.703.94450.06454.00444.06Downstream 451.53449.044.984.59449.41454.00443.41Upstream Pipe Design Options TrueDesign Conduit?TrueDesign Start Invert? TrueDesign Stop Invert?FalseSpecify Local Pipe Constraint? FalsePart Full Design?%100.0Design Percent Full FalseAllow Multiple Barrels?1Barrels (Maximum) FalseLimit Section Size?in0.0Rise (Maximum) Page 2 of 227 Siemon Company Drive Suite 200 W Watertown, CT 06795 USA +1-203-755-1666 4/1/2014 Bentley StormCAD V8i (SELECTseries 1) [08.11.00.44]Bentley Systems, Inc. Haestad Methods Solution CenterWoodridge.stc Conduit Detailed Report: P_1-6x6 Scenario Summary 1ID BaseLabel Notes Base Active TopologyActive Topology Base PhysicalPhysical Base HeadlossHeadloss Base Boundary ConditionBoundary Condition Base Rainfall RunoffRainfall Runoff Base HydrologicHydrologic Base DesignDesign Base System FlowsSystem Flows Base User Data ExtensionsUser Data Extensions Base Calculation Options Gradually Varied Flow Solver Calculation Options Pipe Characteristics MH-12Start Node User Defined ConduitConduit Type OF-2Stop Node Box PipeConduit Shape ft118.0Length (Unified)ConcreteMaterial ft/ft0.006Slope 0.013Manning's n 1Number of Barrels Box Pipe - 72.0 x 72.0 in Conduit Description Hydraulic Summary ft³/s382Flow (N/A)Profile Description ft³/s400Capacity (Full Flow)ft(N/A)Headloss ft³/s18Excess Capacity (Full Flow) ft/s(N/A)Velocity (In) ft³/s400Capacity (Design)ft/s(N/A)Velocity (Out) ft³/s18Excess Capacity (Design) ft/s(N/A)Velocity (Average) Page 1 of 227 Siemon Company Drive Suite 200 W Watertown, CT 06795 USA +1-203-755-1666 4/1/2014 Bentley StormCAD V8i (SELECTseries 1) [08.11.00.44]Bentley Systems, Inc. Haestad Methods Solution CenterWoodridge.stc Conduit Detailed Report: P_1-6x6 EGL (ft) Hydraulic Grade (ft) Depth (ft) Cover (ft) Crown (ft) Ground (ft) Invert (ft) (N/A)(N/A)(N/A)4.59449.41454.00443.41Downstream (N/A)(N/A)(N/A)3.94450.06454.00444.06Upstream Pipe Design Options TrueDesign Conduit?TrueDesign Start Invert? TrueDesign Stop Invert?FalseSpecify Local Pipe Constraint? FalsePart Full Design?%100.0Design Percent Full FalseAllow Multiple Barrels?1Barrels (Maximum) FalseLimit Section Size?in0.0Rise (Maximum) Page 2 of 227 Siemon Company Drive Suite 200 W Watertown, CT 06795 USA +1-203-755-1666 4/1/2014 Bentley StormCAD V8i (SELECTseries 1) [08.11.00.44]Bentley Systems, Inc. Haestad Methods Solution CenterWoodridge.stc Conduit Detailed Report: 2-9x6 Scenario Summary 1ID BaseLabel Notes Base Active TopologyActive Topology Base PhysicalPhysical Base HeadlossHeadloss Base Boundary ConditionBoundary Condition Base Rainfall RunoffRainfall Runoff Base HydrologicHydrologic Base DesignDesign Base System FlowsSystem Flows Base User Data ExtensionsUser Data Extensions Base Calculation Options Gradually Varied Flow Solver Calculation Options Pipe Characteristics CB-1Start Node User Defined ConduitConduit Type MH-12Stop Node Box PipeConduit Shape ft749.0Length (Unified)ConcreteMaterial ft/ft0.006Slope 0.015Manning's n 2Number of Barrels Box Pipe - 108.0 x 72.0 in Conduit Description Hydraulic Summary ft³/s1,391Flow PressureProfile Description ft³/s1,233Capacity (Full Flow)ft5.78Headloss ft³/s-158Excess Capacity (Full Flow) ft/s12.88Velocity (In) ft³/s1,233Capacity (Design)ft/s12.88Velocity (Out) ft³/s-158Excess Capacity (Design) ft/s12.88Velocity (Average) Page 1 of 227 Siemon Company Drive Suite 200 W Watertown, CT 06795 USA +1-203-755-1666 4/1/2014 Bentley StormCAD V8i (SELECTseries 1) [08.11.00.44]Bentley Systems, Inc. Haestad Methods Solution CenterWoodridge.stc Conduit Detailed Report: 2-9x6 EGL (ft) Hydraulic Grade (ft) Depth (ft) Cover (ft) Crown (ft) Ground (ft) Invert (ft) 453.11450.536.473.94450.06454.00444.06Downstream 458.89456.327.726.40454.60461.00448.60Upstream Pipe Design Options TrueDesign Conduit?TrueDesign Start Invert? TrueDesign Stop Invert?FalseSpecify Local Pipe Constraint? FalsePart Full Design?%100.0Design Percent Full FalseAllow Multiple Barrels?1Barrels (Maximum) FalseLimit Section Size?in0.0Rise (Maximum) Page 2 of 227 Siemon Company Drive Suite 200 W Watertown, CT 06795 USA +1-203-755-1666 4/1/2014 Bentley StormCAD V8i (SELECTseries 1) [08.11.00.44]Bentley Systems, Inc. Haestad Methods Solution CenterWoodridge.stc APPENDIX D – ENVIRONMENTAL ASSESSMENT (excerpt only) 25 March 2014 Mr. Kyle Dykes Teague, Nall and Perkins Inc. 1100 Macon Street Fort Worth, Texas 76102 Re: Waters of the United States Delineation, Section 404 Permit Assessment, and Mitigation Assessment Sandy Lake Road; City of Coppell, Dallas County, Texas Dear Mr. Dykes, Integrated Environmental Solutions, LLC. (IES) performed a survey to identify all water features that meet a definition of a water of the United States on approximately 905 feet of channel that parallels Sandy Lake Road, at the intersection of South MacArthur Boulevard in Coppell, Dallas County, Texas (Attachment A, Figure 1). This delineation was conducted to ensure compliance with Section 401 and 404 of the Clean Water Act (CWA), and Executive Order 11990 (Protection of Wetlands) for the proposed development planning. INTRODUCTION Agencies that regulate impacts to the nation’s water resources within Texas include the U.S. Army Corps of Engineers (USACE), the U.S. Environmental Protection Agency (USEPA), the U.S. Fish and Wildlife Service (USFWS), and the Texas Commission on Environmental Quality (TCEQ). Jurisdictional waters of the United States are protected under guidelines outlined in Sections 401 and 404 of the CWA, in Executive Order 11990 (Protection of Wetlands), and by the review process of the TCEQ. The USACE has the primary regulatory authority for enforcing Section 404 requirements for waters of the United States, including wetlands. The definition of waters of the United States, in 33 Code of Federal Regulations (CFR) 328.3, includes waters such as intrastate lakes, rivers, streams (including intermittent streams), mudflats, wetlands, sloughs, wet meadows, or natural ponds and all impoundments of waters otherwise defined as waters of the United States. Also included are wetlands adjacent to waters (other than waters that are themselves wetlands). The term adjacent is defined as bordering, contiguous, or neighboring. Jurisdictional wetlands are a category of waters of the United States and have been defined by the USACE as areas that are inundated or saturated by surface or groundwater at a frequency and duration sufficient to support, and that under normal circumstances do support, a prevalence of vegetation typically adapted for life in saturated soil conditions. Waters of the United States are defined in 33 CFR 328.3 (a) as: 1. All waters which are currently used, or were used in the past, or may be susceptible to use in interstate or foreign commerce, including all waters which are subject to the ebb and flow of the tide; 2. All interstate waters including interstate wetlands; Mr. Kyle Dykes Page 2 Sandy Lake Road Delineation 25 March 2014 3. All other waters such as intrastate lakes, rivers, streams (including intermittent streams), mudflats, sandflats, wetlands, sloughs, prairie potholes, wet meadows, playa lakes, or natural ponds, the use, degradation or destruction of which could affect interstate or foreign commerce including any such waters: i. Which are or could be used by interstate or foreign travelers for recreational or other purposes; or ii. From which fish or shellfish are or could be taken and sold in interstate or foreign commerce; or iii. Which are used or could be used for industrial purpose by industries in interstate commerce; 4. All impoundments of waters otherwise defined as waters of the United States under the definition; 5. Tributaries of waters identified in paragraphs (a)(1)-(4) of this section; 6. The territorial seas; 7. Wetlands adjacent to waters (other than waters that are themselves wetlands) identified in paragraphs 1- 6 above. 8. Waste treatment systems, including treatment ponds or lagoons designed to meet the requirements of CWA (other than cooling ponds as defined in 40 CFR 123.11(m) which also meet the criteria of this definition) are not waters of the United States. On 05 June 2007, the USACE and the USEPA issued joint guidance on delineation of waters on the United States based on the U.S. Supreme Court decisions in Rapanos and Carabell. Under this guidance, potential waters of the United States have been classified as traditional navigable waters (TNW), relatively permanent waters (RPW) (i.e., having flow most of the year or at least seasonally), or non-RPWs. This guidance states that TNWs and RPWs and contiguous or adjacent wetlands to these water features are waters of the United States. Wetlands that are bordering, contiguous, or neighboring another water of the United States is considered adjacent. Additionally, wetlands that are within the 100-year floodplain of another water of the United States are also considered adjacent. Non-RPWs, wetlands contiguous or adjacent to non-RPWs, and isolated wetlands must undergo a “significant nexus” test on a case-by-case basis to determine the jurisdictional nature of these water features. Under the “significant nexus” test a water feature must have substantial connection to a TNW by direct flow, or by indirect biological, hydrologic, or chemical connection. Under the “significant nexus” test the USACE District Engineer must submit the jurisdictional determination (JD) to the regional USEPA office, which makes the decision whether to move the JD to Headquarters USACE to make the final determination. The new guidance does not void the January 2001 decision of the U.S. Supreme Court in Solid Waste Agency of Northern Cook County (SWANCC) v. USACE which disallowed regulation of isolated wetlands under the CWA through the “Migratory Bird Rule.” Previously, the USACE assumed jurisdiction over isolated waters of the United States based on its 1986 preamble stating that migratory birds used these habitats. The “Migratory Bird Rule” provided the nexus to interstate commerce and thus protection under the CWA. However, the new guidance does require that the “significant nexus” test be performed in addition to an analysis of other potential interstate commerce uses for isolated waters. METHODOLOGY Prior to conducting fieldwork, the U.S. Geological Survey (USGS) topographic map (Attachment A, Figure 2), Soil Survey of Dallas County, Texas, the Federal Emergency Management Agency (FEMA) Flood Insurance Rate Map (FIRM) (Attachment A, Figure 4), and aerial photographs of the project site were studied to identify possible waters of the United States and areas prone to wetland development. Mr. Rudi Reinecke and Mr. Ross Rogers of IES conducted the field surveys for potential waters of the United States in accordance with the USACE procedures on 18 February 2014. Wetland delineations were performed on location using the methodology outlined in the 1987 Corps of Engineers Wetland Delineation Manual and the Regional Supplement to the Corps of Engineer Wetland Delineation Manual: Great Plains Region (Version 2.0, March 2010). The presence of a wetland is determined by the positive indication of three criteria (i.e., hydrophytic vegetation, hydrology, and hydric soils). Potential jurisdictional boundaries for Mr. Kyle Dykes Page 3 Sandy Lake Road Delineation 25 March 2014 other water resources (i.e., non-wetland) were delineated in the field at the ordinary high water mark (OHWM). The 33 CFR 328.3(e) defines OHWM as the line on the shore/bank established by flowing and/or standing water, marked by characteristics such as a clear, natural line impressed on the bank, erosion shelving, changes in the character of soil, destruction of terrestrial vegetation, presence of litter and debris, or other appropriate means that consider the characteristics of the surrounding areas. Water feature boundaries were recorded using a Trimble GeoXT global positioning system (GPS) unit capable of sub-meter accuracy. Photographs were taken at representative points across the survey corridor, which are provided in Attachment B. RESULTS Literature Review No water features are illustrated on the USGS topographic map (1997), however, there are “V”-shaped contours indicating confined flow in the project vicinity. The Soil Survey of Dallas County, Texas illustrates a tributary within the project site. The FEMA FIRM illustrates the project site within Zone X (areas of 1% annual chance flood with average depths of less than 1 foot or with drainage areas less than 1 square mile) and Zone X (areas determine to be outside the 500-year floodplain) (Map Number 48113C0155J effective 23 August 2001). The FEMA FIRM does not illustrate any water features within the project site. The Natural Resource Conservation Service (NRCS) digital soil survey data for Dallas County (Attachment A, Figure 3) mapped two soil series within the project site – Silawa fine sandy loam, 2 to 8 percent slopes, eroded and Trinity clay, occasionally flooded. Trinity clay, when found within depressions, is listed on the Hydric Soils of Texas list prepared by the National Technical Committee for Hydric Soils (revision April 2012). Site Survey The project site was comprised of two habitat communities; urban riparian and maintained channel. The urban riparian community was dominated by red mulberry (Morus rubra), black willow (Salix nigra) and cattails (Typha latifolia) along the edge of the tributary. The slopes of the channel were comprised of cool season annuals, giant ragweed (Ambrosia trifida), and Johnsongrass (Sorghum halepense). This vegetation extended from the limits of the ordinary high water mark up the slope for approximately fifteen feet on either side of the channel before transitioning to maintained grasses. The maintained channel flowed through two separate concrete drop structures. Cattails and black willow were located along the sediment deposits within the concrete drop structures in the maintained channel. The immediate topography of the area was flat, with the overall topography sloping from west to east as the landscape transitioned into the floodplain of the Elm Fork Trinity River. The tributary entered the project site through a single concrete channel, flowing from west to east. The tributary paralleled Sand Lake Drive for approximately 3,000 feet before crossing Sandy Lake Road and emptying into Denton Creek, a tributary of the Elm Fork Trinity River. The delineated tributary within the project site is detailed below (Attachment A, Figure 5 and Table 1). Table 1 Waters Delineated in Project Study Area Water Identification Water of the United States Hydraulic Characteristics Classification Length (Linear Feet) Area (Acre) Tributary 1 Yes Intermittent RPW 905 0.24 JURISDICTIONAL TOTAL 905 0.24 Tributary 1 was a channelized drainage that displayed intermittent flow characteristics based on the degree of incisement and amount of flow observed during the field inspection. It is IES’ opinion that the flow in this tributary is seasonal and would be classified as a RPW. Upstream from the project site, the tributary was a concrete channel that provided drainage for storm water culverts from several surrounding residential neighborhoods. Within the project site the tributary’s width averaged eight feet. Immediately downstream of the project site Tributary 1 converged with Denton Creek, a tributary of the Elm Fork Trinity River. The Elm Fork Trinity River conveys water to the West Fork Trinity River, a TNW. Given Tributary 1’s indirect connection to a TNW it is IES’ professional opinion Mr. Kyle Dykes Page 4 Sandy Lake Road Delineation 25 March 2014 that this tributary and all of its channels would meet a definition of a water of the United States and therefore be regulated under Section 404 of the CWA. Compensatory Mitigation Cost Opinion The USACE Fort Worth District has a Regional General Condition that, for projects with impacts exceeding 0.1 acre or 300 linear feet of tributary impacts, compensatory mitigation will be required to ensure that the activity results in minimal adverse effects to the aquatic environment. The USACE recently published the Fort Worth District Guidance for performing compensatory mitigation on streams in the Stream Mitigation Method. In following this guidance, the Fort Worth District requires that at least 50 percent of the impacted stream be mitigated utilizing a mitigation bank that has conducted either in-stream or riparian buffer mitigation. The remaining 50 percent of the impacted stream would be allowed to utilize the “legacy-style” mitigation banks. All new in-stream or riparian buffer mitigation banks are credited and debited utilizing the Texas Rapid Assessment Method (TXRAM) versus the “legacy-style” mitigation banks are based on standardized multipliers. There are multiple mitigation banks available; however, the following multipliers and cost estimates per credit are being provided for Trinity River Mitigation Bank (TRMB), a “legacy-style” mitigation bank, and Mill Branch Mitigation Bank (MBMB), a riparian- buffer mitigation bank. These two banks are used here due to the project being located in their primary service areas and advertised costs per credit. TXRAM is a condition based assessment tool for evaluating streams and wetlands prepared by the USACE Fort Worth Regulatory Branch for use in Texas in both Fort Worth and Tulsa Districts. The TXRAM modules were developed to provide consistent methods for wetland and stream assessment and will be used for assessing the condition of the water features. This standardized condition assessment of the water features was developed to provide a tool that compares water features. TXRAM has many uses, but for the purpose of this project, it documents the overall condition of the different Stream Reaches (Attachment A, Figure 6) which will then be used to document the necessary compensatory mitigation for the proposed project impacts utilizing the Stream Mitigation Method as published by the USACE in their CESWF-13-MIT-1 Public Notice on 02 October 2013. The TXRAM Streams Module was developed to gauge the integrity of a stream, assuming that stream condition is a product of complex interactions among biological, chemical, and physical processes. TXRAM utilizes metrics based on these interactions, as well as, visible physical and biological characteristics to provide an overall score of the stream condition. The project site was divided into two Stream Assessment Reaches (SAR) based on overall characteristics of the site. SAR A contained a trapezoidal channel that had some shrub scrub vegetation on slopes of the riparian corridor and SAR B was a concrete lined section of the tributary. Specifically SAR A was identified as a deeply incised channel with a natural substrate bed and bank. Overhanging vegetation with woody and leafy debris was identified as part of the in-stream habitat, and an early successional riparian buffer was identified along both banks of SAR A. Additionally SAR A displayed approximately 25 percent active bank erosion along both banks of the tributary. SAR B was identified as a concrete channel with an artificial bed and bank. Neither in-stream habitat nor riparian buffer were identified along SAR B. The artificially stabilized banks exhibited no erosion along SAR B. The completed TXRAM Data Forms are provided in Attachment C, which documents all of the scoring matrices. Table 2 provides the cost opinion of the proposed compensatory mitigation for the complete enclosure of the tributary. As stated previously, there are other mitigation options; however, there would be service area multipliers and these mitigation banks do not publish their rates. As the project moves forward, an actual cost estimate should be acquired to verify the prices and potentially have the mitigation banks compete for the project. Mr. Kyle Dykes Page 5 Sandy Lake Road Delineation 25 March 2014 Table 2. Proposed Compensatory Mitigation Cost Opinion Utilizing the Stream Mitigation Method SAR Total Length LEGACY-STYLE BANK1 RIPARIAN BUFFER STYLE BANK2 Length3 Multiplier Credits4 Estimated Cost6 Length3 TxRAM Score Credits5 Estimated Cost7 A 302.4 151.2 0.008 1.2 $21,000.00 151.2 43.4 65.6 $78,720.00 B8 225.8 NA NA NA NA NA 31.9 NA NA A 198.6 99.3 0.008 0.8 $14,000.00 99.3 43.4 43.1 $51,720.00 B8 178.5 NA NA NA NA NA 31.9 NA NA Subtotal $35,000.00 $130,440.00 Grand Total $165,440.00 1Cost opinion uses Trinity River Mitigation Bank for the Legacy-Style mitigation bank 2Cost opinion uses Mill Branch Mitigation Bank as the Riparian Buffer-Style mitigation bank 3Each mitigation bank type is allocated 50 percent of the impacts to reduce the overall mitigation cost 4TRMB has a 0.008 multiplier to each linear foot of impacted intermittent stream to calculate credits 5MBMB multiplies the linear feet of impacted stream to the TXRAM score (converted from percent to decimal) to calculate credits 6TRMB cost per credits is $17,500.00 at the time this report is dated 7MBMB cost per credits is $1,200.00 at the time this report is dated 8USACE Fort Worth District does not require compensatory mitigation for previously concrete-lined streams CONCLUSIONS Delineation Summary To summarize the delineation, one potentially jurisdictional water was identified and delineated within the Project Site – Tributary 1. Tributary 1 was approximately 905 linear feet long within the project area and measured 0.24 acre below the OHWM. Based on the June 2007 guidance, it is IES’ professional opinion that this feature does meet the definition of a water of the United States as this is a tributary of a TNW and is considered a RPW. This delineation is based on professional experience in the approved methodology, and from experience with the USACE Fort Worth District regulatory biologists. However, this delineation does not constitute a jurisdictional determination of waters of the United States. Only the USACE can make the final jurisdictional determination, which can be based on the professional opinions presented in this report. The project planning is to enclose the tributary within the project site to facilitate reduced maintenance and a pocket park. Due to the length of the impacts, the project would require compensatory mitigation and following the new USACE Fort Worth District Stream Mitigation Method of utilizing multiple mitigation bank types, the cost opinion at the time this letter is dated, is approximately $165,440.00. There are multiple factors that affect the cost estimates and therefore should be visited again during the Section 404 permitting process. IES appreciates the opportunity to work with you and Teague, Nall and Perkins, Inc. on this project, and hope we may be of assistance to you in the future. If you have any comments, questions, or concerns, please do not hesitate to contact me or Rudi Reinecke at 972/562-7672 or (RRogers@intenvsol.com or Rreinecke@intenvsol.com). Sincerely, Integrated Environmental Solutions, LLC. Ross Rogers Environmental Specialist Attachments File ref: 04.080.032 Figure 6 Texas Rapid Assessment Method Stream Assessment Reaches County: Dallas State: Texas Date map created: 03/20/2014 Source: 2012 USDA FSA Aerial Photography . 1 inch = 200 feet 0 200 400 600 Feet Project Site Stream Assessment Reaches (SAR) Tributary SAR A (302.4 Feet) SAR B (225.8 Feet) SAR A (198.6 Feet) SAR B (178.5 Feet) APPENDIX E – OPNIION’S OF PROBABLE CONSTRUCTION COST (OPCC) Conceptual Opinion of Probable Construction Cost Client:Date:1-Apr-14 Project:Prepared By:KJD tnp no.:Checked By:SCW Sheet:1 of 2 Spec No.Item Item Description Quantity Unit Unit Cost Item Cost 1 Mobilization (5% of Items 3-11)1 LS 57,000$ 57,000$ 2 Site Preparation 8 STA $3,000.00 24,000$ 3 Unclassified Channel Excavation (Export)1,500 CY $10.00 15,000$ 4 Embankment (Import)3,000 CY $15.00 45,000$ 5 2-9x6 Concrete Box Culvert (MBC)750 LF $1,150.00 862,500$ 6 Concrete Slab Beam Enclosure (1 Transition)350 SF $80.00 28,000$ 7 Concrete Heawall/Wingwall 1 EA $25,000.00 25,000$ 8 5" Concrete RipRap (Channel Bottom & Transitions)90 SY $30.00 2,700$ 9 6'x6' RCB by Tunnel & Jacking (@ MacArthur)110 LF $800.00 88,000$ 10 Site Stabilization 7,000 SY $4.50 31,500$ 11 Utility Adjustments (Budget)1 LS $12,000.00 12,000$ 12 SWPPP 1 LS $5,000.00 5,000$ 13 14 Construction Subtotal 1,195,700$ 15 Contingencies (25%)298,925$ 16 Option 1 Construction Total 1,495,000$ 17 18 Environmental Mitigation 1 LS $165,000.00 $165,000.00 19 Option 1 Project Total 1,660,000$ 20 City of Coppell Woodridge Channel CPL13314 Option 1: Box Culvert Enclosure No Design Completed Preliminary Design Final Design Conceptual Opinion of Probable Construction Cost Client:Date:1-Apr-14 Project:Prepared By:KJD tnp no.:Checked By:SCW Sheet:2 of 2 Spec No.Item Item Description Quantity Unit Unit Cost Item Cost 1 Mobilization (5% of Items 3-14)1 LS 77,000$ 77,000$ 2 Site Preparation 8 STA $3,000.00 24,000$ 3 Unclassified Channel Excavation (Export)1,500 CY $10.00 15,000$ 4 Embankment (Import)3,000 LS $15.00 45,000$ 5 25'x6' Con/Span Pre-Cast Bridge Stucture (O-Series)750 LF $1,100.00 825,000$ 6 Concrete Slab Beam Enclosure (1 Transition)350 SF $80.00 28,000$ 7 30" Drilled Concrete Piers (Con/Span Support, 16' c-c, 15' deep)1,410 LF $80.00 112,800$ 8 Structural Concrete (Grade Beam Cap, 3'x2.5', each side)420 CY $610.00 256,200$ 9 Concrete Heawall/Wingwall 1 EA $25,000.00 25,000$ 10 5" Concrete RipRap (Channel Bottom & Transitions)2,170 SY $30.00 65,100$ 11 6'x6' RCB by Bore & Jacking (@ MacArthur)110 LF $800.00 88,000$ 12 Site Stabilization 7,000 SY $4.50 31,500$ 13 Utility Adjustments (Budget)1 LS $12,000.00 12,000$ 14 SWPPP 1 LS $5,000.00 5,000$ 15 16 Construction Subtotal 1,609,600$ 17 Contingencies (25%)402,400$ 18 Option 2 Construction Total 2,012,000$ 19 20 Environmental Mitigation 1 LS $165,000.00 $165,000.00 21 Option 2 Project Total 2,177,000$ 22 City of Coppell Woodridge Channel CPL13314 Option 2: Con/Span Enclosure No Design Completed Preliminary Design Final Design