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Home My WebLink About56 Development Permit 402 Easterwood Well No 2DRAINAGE REPORT FOR EASTERWOOD WELL NO. 2 UNION PACIFIC RESOURCES COMPANY John H. Jones, A-148 College Station, Brazos County, Texas July 23, 1996 DEVELOPED BY: Union Pacific Resources Company c/o Duane Phillippi 7300 N. F.M. 2818, Suite 200 Bryan , TX 77803 ( 409)778-4867 PREPARED BY: Kling Engineering & Surveying 4103 Texas Avenue , Suite 212 Bryan, TX 77802 (409)846-6212 Drainage Report for Easterwood Well No. 2 Union Pacific Resources Company John H. Jones Survey, A-148 College Station, Brazos County, Texas July 23, 1996 GENERAL LOCATION & DESCRIPTION The proposed drilling site for the Easterwood #2 is located approximately 700' east of the State Highway 60 bridge at Turkey Creek Road (See Appendix 3: "Vicinity Map"). For impact purposes this well is considered to be rural. Currently the site is vacant with field grasses, brush and trees. Proposed improvements consist of constructing a 330' x 230' drilling pad and constructing an access road from the highway 60 access road to the drilling pad. Two corrugated metal pipes will be installed along the access road to facilitate drainage . DRAINAGE BASINS & SUB-BASINS The primary drainageway for this site is White Creek. Runoff proceeds to the creek from two sub-basins. Sub-Basin 1 runoff flows overland and through highway 60 drainage structures and into a tributary of White Creek and ultimately into White Creek. Sub-Basin 2 runoff flows overland and into the Easterwood airport storm sewer system and ultimately into White Creek. Neither the drilling pad nor the access road lies within the 100 year floodplain according to the Flood Insurance Rate Map for Brazos County, Texas, and Incorporated Areas , Map No . 48041C0143 C, effective July 2, 1992 (See Appendix 2: "Flood Plain Map"). Two primary studies have been performed on White Creek and its tributaries. The first is a study performed by the Federal Emergency Management Agency in July, 1992, titled El.ood Insurance Study -Brazos County, Texas and Incorporated Areas. The purpose of this report was to investigate the existence and severity of flood hazards for Brazos County and to aid in the administration of the National Flood Insurance Act of 1968 and the Flood Disaster Protection Act of 1973 . The second study is the Stormwater Management Plan, Phase III, performed by Walton and Associates -Consulting Engineers, Inc. contracted with the City of College Station in 1987. The purpose of this study was to gain knowledge of the existing and future drainage conditions in the City and to identify flood problems and flood prone areas. Easterwood Well #2 Drainage Report Page 2 DRAINAGE DESIGN CRITERIA/FACILITY DESIGN A topographic plat was prepared using City of College Station 2' contour maps to show existing conditions, proposed improvements, and to delineate the drainage areas. Under proposed conditions, three drainage areas exist; DA-01, DA-02, and DA-03. Of these, DA-01 and DA- 02 are in Sub-Basin 1 and DA-03 is in Sub-Basin 2 with DA-01 draining to a 24" RCP under the Easterwood· airport entrance/exit drive. Under proposed conditions, five drainage areas are delineated due to the configuration of the access road and well pad; DA-Nla, DA-Nlb, DA-N2, DA-N3, and DA-N4. Of these, DA-Nla through DA-N3 are in Sub-Basin 1 and DA-N4 is in Sub-Basin 2. Additionally, DA-Nla and DA-Nlb drain to the 24" culvert. The capacity of this culvert assuming a minimal slope of 0 . 8 % is 20 cfs, post developed flow to the culvert is < 6 cfs for all storm events. The Rational Method was used to calculate the peak runoff using the 25 year event as the design storm. The tables in Appendix 5 summarize the parameters used and the results they produced (See Appendix 5). Two corrugated metal pipe culverts will be required beneath the access road. It is recommended that a swale be graded around the pad to direct runoff through Sub-Basin 1 and preclude runoff From Sub-Basin 2 (see Appendix 4). Culverts for drainage areas DA-Nla and DA-N2 were designed using Manning's Equation (See Appendix 6). Difference between pre and post developed flowrates for the two sub-basins is as follows: Sub-Basin Q10pr/ QIOpost Q25pre/ Q25post Q100pr/Q100post (cfs) (cfs) (cfs) #1 20. 7/24.9 23. 7/28.6 28.0/33.8 #2 21.2/17.5 24.3/20.1 28.8/23.9 TOTAL 41.9/42.4 48.0/48. 7 56.8/57.7 Table 1 CONCLUSIONS Easterwood Well #2 is considered to be a rural well, and the drainage analysis has been performed accordingly. Two 18" corrugated metal pipes will be installed at proper locations along the proposed access road to facilitate drainage. No adverse impact from the 25 year event is expected to adjoining or downstream landowners or downstream drainage structures. Easterwood Well #2 Drainage Report Page 3 APPENDICES 1) General Location Map -U.S. G. S. Quad 2) Flood Insurance Rate Map -FEMA 3) Vicinity Map 4) Topographic plat -Kling Engineering 5) H ydrologic -Rational Method 6) Hydraulic -Manning's Equation kcs95-01 b : \cast#2 .rpt 0 1000 0 1000 2000 3000 4000 5000 6000 7000 FEET s:::::J3::13====::i:======:c:===::::E:=====i============3:=====i CONTOUR INTERVAL 10 FEET DOTTED LINES REPRESENT 5-FOOT CONTOURS NATIONAL GEODETIC VERTICAL DATUM OF 1929 . ; APPENDIX 5 HYDROLOGIC CALCULATIONS RATIONAL METHOD 7/19/96 A&M EASTERWOOD WELL NO . 2 HYDROLOGIC COMPUTATIONS PRE-DEVELOPED CONDITIONS: LAND USE: VACANT LAND COVER : FIELD GRASSES/BRUSH/WOODED/CONC. DRIVE AREA: 14.316 SUB-BASINS: 3 AREA DESCRIPTION : (acres) DA-01 1.750 AVE. SLOPE OF 2.3% TO 24" R.C .P.@ INTERSECTION DA-02 5.549 AVE . SLOPE OF 1% TO AIRPORT EXIT DRIVE (N) DA-03 7.017 AVE . SLOPE OF 1% TO AIRPORT EXIT DRIVE (S) TOTAL 14.316 PRE-DEVELOPED SUB-BASIN CHARACTERISTICS: HYDRAULIC SLOPE AVERAGE VELOCITY TIME OF RUNOFF INTENSITIES LENGTH (hi) (F/C .O.C.S . D.P.&D .S.) CONCENTRATION COEFFICIEN i(10) i(25) i(100) (ft) (%) (ft/sec) (min) (C) (in/hr) (in/hr) (in/hr) DA-01 866 2 .3 2.76 5 0.27 8.63 9.86 11 .64 DA-02(1) 811 1.0 0.85 16 0.27 DA-02(2) 341 0.8 2.3 2 0.90 (TOTAUAVE) 18 0.46 6.56 7.52 8.90 DA-03(1) 884 1.0 0.85 17 0.27 DA-03(2) 507 0.7 1.98 4 0.90 (TOTAUAVE) 21 0.50 6.05 6.94 8.22 Q=C*i*A RETURN BASIN 10 YR 25 YR 100 YR DA-01 4.08 4 .66 5.50 (cfs) DA-02 16.63 19.05 22.54 DA-03 21 .20 24 .32 28.81 TOTALS 41 .91 48 .03 56 .85 PRE-DEVELOPED 7122196 A&M EASTERWOOD WELL NO . 2 HYDROLOGIC COMPUTATIONS POST DEVELOPED SUB-BASINS !THESE ARE BASICALLY THE SAME AS PRE-DEVELOPED SUB-BASINS BUT ARE ADJUSTED TO REPRESENT PROPOSED DEVELOPED CONDITIONS AREA DESCRIPTION : (acres) DA-N1a 1.038 AVE. SLOPE OF 2 .3% TO ACCESS ROAD DA-N1b 0.712 AVE. SLOPE OF 2 .3% TO 24" R.C .P. @ INTERSECTION DA-N2 0 .542 AVE. SLOPE OF 1% TO ACESS ROAD DA-N3 5.877 AVE . SLOPE OF 1% TO AIRPORT EXIT DRIVE (N) DA-N4 6 .147 AVE . SLOPE OF 1% TO AIRPORT EXIT DRIVE (S) TOTAL 14.316 · PRE-DEVELOPED SUB-BASIN CHARACTERISTICS: HYDRAULIC SLOPE AVERAGE VELOCITY TIME OF RUNOFF INTENSITIES LENGTH (hi) (F/C .O .C.S . D.P.&D .S.) CONCENTRATION COEFFICIEN i(10) i(25) i(100) (ft) (%) (ft/sec) (min) (Cave) (in/hr) (in/hr) (in/hr) DA-N1a 390 2.3 2.76 2 0.27 8.63 9.86 11 .64 DA-N1b 476 2 .3 2 .76 3 0 .30 8.63 9.86 11 .64 DA-N2 435 1.0 0.85 9 0 .27 8.63 9.86 11 .64 DA-N3(1) 1014 1.0 0 .85 20 0.43 DA-N3(2) 450 0.8 2.3 3 0 .90 (TOTAUAVE) 23 0 .57 5.75 6 .60 7 .83 DA-N4(1) 979 1.0 0.85 19 0 .27 DA-N4(2) 594 0.7 1.98 5 0.90 (TOTAUAVE) 24 0.51 5.62 6.45 7.65 Q=C*i*A RETURN BASIN 10 YR 25 YR 100 YR DA-N1a 2.42 2 .76 3.26 (cfs) DA-N1b 1 .84 2 .11 2 .49 DA-N2 1.26 1.44 1.70 DA-N3 19.42 22.29 26.42 DA-N4 17 .54 20.13 23 .88 TOTALS 42 .48 48 .73 57.75 POST-DEVELOPED APPENDIX 6 HYDRAULIC CALCULATIONS MANNING'S EQUATION Project Description Project File Worksheet Flow Element Method Solve For Input Data Mannings Coefficient Channel Slope Diameter Results Depth Discharge Flow Area Wetted Perimeter Top Width Critical Depth Percent Full Critical Slope Velocity Velocity Head Specific Energy Froude Number Maximum Discharge Full Flow Capacity Full Flow Slope 24" RCP CAPACITY Worksheet for Circular Channel untitled 24 " Circu lar Channel Manning 's Formula Full Flow Capacity 0.013 0.008000 V : H 2.00 ft 2.00 ft 20 .23 ffl/s 3.14 ft 2 6.28 ft 0.00 ft 1.61 ft 100.00 0.008226 V : H 6.44 ft/s 0.64 ft FULL ft FULL 21 .76 ffl/s 20 .23 ffl/s 0.008000 V : H Kling E ngineering & Surveying Jul25, 1996 12:54:04 Haestad M ethods, Inc . 37 Brookside Road W aterbury, CT 067 08 (203) 755-1666 F lowMaster v4 .1 c Page 1 of 1 Project Description Project File Worksheet Flow Element Method Solve For Input Data Mannings Coefficient Channel Slope Discharge Results Depth Diameter Flow Area Wetted Perimeter Top Width Critical Depth Percent Full Critical Slope Velocity Velocity Head Specific Energy Froude Number Maximum Discharge Full Flow Capacity Full Flow Slope CULVERT FOR DA-N1 a Worksheet for Circular Channel e:\haestad\pi\east2.fm2 EASTERWOOD #2 ACCESS RD CULVERTS Circular Channel Manning's Formula Full Flow Diameter 0.024 0.010000 V : H 2.76 ft3/s 1.14 ft 1.14 ft 1.03 ft2 3.59 ft 0.00 ft 0.69 ft 100.00 0.022232 V : H 2.69 ft/s 0.11 ft FULL ft FULL 2.97 ft3/s 2.76 ft3/s 0.010000 V : H Kling Engineering & Surveying Jul23, 1996 11 :02:02 Haestad Methods, Inc. 37 Brookside Road Waterbury, CT 06708 (203) 755-1666 FlowMaster v4.1 c Page 1of1 Project Description Project File Worksheet Flow Element Method Solve For Input Data Mannings Coefficient Channel Slope Discharge Results Depth Diameter Flow Area Wetted Perimeter Top Width Critical Depth Percent Full Critical Slope Velocity Velocity Head Specific Energy Froude Number Maximum Discharge Full Flow Capacity Full Flow Slope CULVERT FOR DA-N2 Worksheet for Circular Channel e:\haestad\pi\east2.fm2 EASTERWOOD #2 ACCESS RD CULVERTS Circular Channel Manning's Formula Full Flow Diameter 0.024 0.010000 V : H 1.44 ft3/s 0.90 ft 0.90 ft 0.63 ft2 2.81 ft 0.00 ft 0.53 ft 100.00 0.023739 V : H 2.28 ft/s 0.08 ft FULL ft FULL 1.55 ft3/s 1.44 ft3/s 0.010000 V : H Kling Engineering & Surveying Jul23, 1996 11 :01 :23 Haestad Methods, Inc. 37 Brookside Road Waterbury, CT 06708 (203) 755-1666 FlowMaster 114 .1 c Page 1of1