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Drainage Analysis
Drainage Analysis WE RENT STORAGE 2672 HORSE HAVEN LANE College Station, Brazos County, Texas March, 2012 MICHAEL G. HESTER ,. .., 69104 ..� '� OS %�- ANAL ��(� aood� � THE SEAL APPEARING ON THIS DOCUMENT WAS AUTHORIZED BY: MICHAEL G. HESTER, P.E. #69104 ON March 21, 2012. RELEASED FOR RECORD HESTER ENGINEERING COMPANY #F-3476. Prepared By: Michael G. Hester, P.E. Hester Engineering Company 7607 Eastmark Drive, Suite 253-B College Station, TX 77840 (979) 693-1100 mhesterChester-engr.com CERTIFICATION This report for the drainage design of (WE RENT STORAGE) was prepared by me (or under my supervision) in accordance with provisions of the Bryan/College Station Unified Drainage Design Guidelines for the owners of the property. All licenses and permits required by any and all state and federal regulatory agencies for the proposed drainage improvements have been issued." MC EL G, HILSTER ,. 69104 14 THE SEAL APPEARING ON THIS DOCUMENT WAS AUTHORIZED BY: MICHAEL G. NESTER, P.E. #69104 ON March 21, 2012. RELEASED FOR RECORD HESTER ENGINEERING COMPANY #F-3476. WE RENT STORAGE IJ-_I_ I i - . --I I I L I I. TL L7 _-L- V Drainage Analysis Narrative i-� WE RENT STORAGE i College Station, Brazos County, Texas —� March 2012 f u The site is located at the intersection of Horse Haven Lane and Appomattox Drive in the Horse ' Haven Subdivision. The legal description is We Rent Storage, Block 1, Lot 1 is 2.60 acres, zoned PDD and i presently the final plat has been submitted for consideration of the CoCS Planning & Zoning i Commission. The entire site is in the City limits and a personal storage facility is planned for the site. _ The Cities staff planner is Lauren Hovde. i i The site was previously an oil well site with a pumper jack and storage tank and is presently vacant (� except for a 0.09 acre cell tower site. The pumper jack, storage tank, infrastructure and gravel have been removed and the site leveled for the proposed improvements. i D Runoff from the site begins along the right of way of Horse Haven Lane and flows south toward Wolf r Pen Creek. Paralleling the south property line of the site is an existing ditch in a drainage and conservation easement. Once in the ditch the runoff travels east to a pond and then to Wolf Pen Creek. The Federal Emergency Management Agency (FEMA) Flood Insurance Rate Map (48041C0 163C) show a portion of the tract in the floodway however a letter of map revision if000dway) removed the tract from the floodway. Detention is not required nor planned for the site due to its location in the watershed. Table B-1 "Detention Requirement by Watershed and Watershed Reach". The Cities staff engineer is Josh Norton. The site is being improved by Alton Ofczarzak, Managing Member, TDG Management, LP. 4060 Highway 6 South, College Station, Texas 77845, 979-690-1504. Proposed Improvements The general plan to manage storm runoff from the improvements is by directing the runoff from the roofs and pavement through the driveways into grate inlets, a private underground storm drain system to an outf all structure and then into the existing ditch along the south side of the site. Coordination or permitting with other entities is not planned nor required. One drainage report dated March 22, 2012, one set of construction drawings comprise the drainage report for this project. SECTION IX APPENDIX B — REGION'S WATERSHEDS Table B-1 (continued) Detention Requirements by Watershed and Watershed Reach Reference Section II, Paragraph B1, page 2 of 18 Channel Reach Detention Watershed For Flood Name From To Control Wickson Creek Green Branch Loop, Evaluate Steep Hollow Easterling Drive Green Branch Loop, Upstream Required Branch Easterling Drive Thom sons Creek FM 2818 Evaluate Still Creek FM 2818 Upstream Required Thompsons Thom sons Creek N. Texas Avenue Evaluate N. Texas Avenue Upstream Required Branch River SH 21 Not Required ThomBrazos Oons SH 21 Thom sons Branch Evaluate Creek Creek Thom sons Branch Upstream Required Brazos River SH 47 Not Required Turkey Creek SH 47 W. Villa Maria Drive Evaluate W. Villa Maria Drive Upstream Required Brazos River Unnamed Road off White Not Required Creek Road White Creek Unnamed Road off FM 2818 Evaluate White Creek Road FM 2818 Upstream Required Carter Creek Dartmouth Street Not Required Dartmouth Street George Bush Drive at Evaluate Wolf Pen Creek Texas Avenue George Bush Drive at Upstream Required Texas Avenue STORMWATER DESIGN GUIDELINES Page 2 of 24 APPENDIX B: REGION'S WATERSHEDS Effective February 2007 As Revised February 2009 HORSE HAVEN PHASE FOUR A14 DRAINAGE AREA HYDROLOGY & GRATE INLET DEPTH Hydrology Report ,r ,- i y HydraFlow Express Extension for AutoCAD® Civil 3D® 2009 by Autodesk, Inc. GRATE INLET #DS-1 y Hydrograph type = Rational } Storm frequency (yrs) = 100 Drainage area (ac) = 0.200 Rainfall Inten (in/hr) = 11.639 OF Curve = BrazCnty.IDF � y l y i I i) Runoff Hydrograph (D Q (cfs) 100-yr frequency 0 5 10 ) — Runoff Hyd - Qp = 2.10 (cfs) ) Peak discharge (cfs) Time interval (min) Runoff coeff. (C) Tc by User (min) Rec limb factor Friday, Mar 23 2012 = 2.095 = 1 = 0.9 = 10 = 1.00 Hydrograph Volume = 1,257 (cult); 0.029 (acft) 15 Q (cfs) 3,00 2.00 1.00 20 Time (min) Inlet Report Hydraflow Express Extension for AutoCAD® Civil 3D® 2009 by Autodesk, Inc. Friday, Mar 23 2012 Grate Inlet #DS-1 NOTE: Q IS 125% OF ACTUAL FOR CLOGGING Drop Grate Inlet Calculations Location = Sag Compute by: Known Q Curb Length (ft) = -0- Q (cfs) = 2.63 Throat Height (in) = -0- Grate Area (sqft) = 1.14 Highlighted Grate Width (ft) = 2.16 Q Total (cfs) = 2.63 Grate Length (ft) = 2.16 Q Capt (cfs) = 2.63 Q Bypass (cfs) = -0- Gutter Depth at Inlet (in) = 2.61 Slope, Sw (ft/ft) = 0.032 Efficiency (%) = 100 Slope, Sx (ft/ft) = 0.032 Gutter Spread (ft) = 15.75 Local Depr (in) = -0- Gutter Vel (ft/s) = -0- Gutter Width (ft) = 2.16 Bypass Spread (ft) = -0- Gutter Slope (%) = -0- Bypass Depth (in) = -0- Gutter n-value = -0- Hydrology Report - Hydraflow Express Extension for AutoCAD® Civil 3D® 2009 by Autodesk, Inc. Grate Inlet #DS-2 O Hydrograph type = Rational Storm frequency (yrs) = 100 (� Drainage area (ac) = 0.327 () Rainfall Inten (in/hr) = 11.639 O IN Curve = BrazCnty.IDF O\ ( ( ) ( ) ( (� Runoff Hydrograph (� (� Q (cfs) 100-yr frequency 0.00 -9 0 5 — Runoff Hyd - Qp = 3.43 (cfs) 10 Peak discharge (cfs) Time interval (min) Runoff coeff.(C) Tc by User (min) Rec limb factor Friday, Mar 23 2012 = 3.425 1 = 0.9 = 10 = 1.00 Hydrograph Volume = 2,055 (cult); 0.047 (acft) 15 Q (cfs) 4.00 3.00 2.00 1.00 -X- 0.00 20 Time (min) Inlet Report Hydraflow Express Extension for AUtoCAD® Civil 3D@ 2009 by Autodesk, Inc. Friday, Mar 23 2012 Grate Inlet #DS-2 NOTE: Q IS 125% OF ACTUAL FOR CLOGGING Drop Grate Inlet Calculations Location = Sag Compute by: Known Q Curb Length (ft) _ -O- Q (cfs) = 4.33 Throat Height (in) _ -0- Grate Area (sqft) = 1.14 Highlighted Grate Width (ft) = 2.16 Q Total (cfs) = 4.33 Grate Length (ft) = 2.16 Q Capt (cfs) = 4.33 Q Bypass (cfs) _ -0- Gutter Depth at Inlet (in) = 5.98 Slope, Sw (ft/ft) = 0.032 Efficiency (%) = 100 Slope, Sx (ft/ft) = 0.032 Gutter Spread (ft) = 33.51 Local Depr (in) _ -0- Gutter Vel (ft/s) _ -0- Gutter Width (ft) = 2.16 Bypass Spread (ft) _ -0- Gutter Slope (%) _ -0- Bypass Depth (in) _ -0- Gutter n-value = -0- Hydrology Report ;r Hydraflow Express Extension for AutoCAD® Civil 3D® 2009 by Autodesk, Inc. i� Grate Inlet #DS-3 Hydrograph type = Rational Storm frequency (yrs) = 100 y Drainage area (ac) = 0.410 - Rainfall Inten (in/hr) = 11.639 OF Curve = BrazCnty.IDF �u i y I i Runoff Hydrograph i) Q (cfs) 1 00-yr frequency 18 19 Runoff Hyd - Qp = 4.29 (cfs) 10 Peak discharge (cfs) Time interval (min) Runoff coeff. (C) Tc by User (min) Rec limb factor Friday, Mar 23 2012 = 4.295 = 1 = 0.9 10 1.00 Hydrograph Volume = 2,577 (cult); 0.059 (acft) 15 Q (cfs) 5.00 4.00 3.00 2,00 1.00 0 11 zu Time (min) Inlet Report Hydraflow Express Extension for AutoCAD® Civil 3D® 2009 by Autodesk, Inc. Friday, Mar 23 2012 Grate Inlet #DS-3 NOTE: Q IS 125% OF ACTUAL FOR CLOGGING Grate Inlet Calculations Location = On grade Compute by: Known Q Curb Length (ft) _ -0- Q (cfs) = 5.36 Throat Height (in) _ -0- Grate Area (sqft) _ -0- Highlighted Grate Width (ft) = 4.18 Q Total (cfs) = 5.36 Grate Length (ft) = 2.16 Q Capt (cfs) = 3.55 Q Bypass (cfs) = 1.81 Gutter Depth at Inlet (in) = 4.94 Slope, Sw (ft/ft) = 0.053 Efficiency (%) = 66 Slope, Sx (ft/ft) = 0.053 Gutter Spread (ft) = 7.77 Local Depr (in) _ -0- Gutter Vel (ft/s) = 3.35 Gutter Width (ft) = 2.16 Bypass Spread (ft) = 5.28 Gutter Slope (%) = 0.50 Bypass Depth (in) = 3.36 Gutter n-value = 0.013 Hydrology Report —1 Hydraflow Express Extension for AutoCAD® Civil 3D® 2009 by Autodesk, Inc. r Grate Inlet #DS-4 1 Hydrograph type = Rational (� Storm frequency (yrs) = 100 (� Drainage area (ac) = 0.230 �) Rainfall Inten (in/hr) = 11.639 (� OF Curve = BrazCnty.IDF ( ( ( ) ( ) O Runoff Hydrograph i) ( i Q (cfs) 100-yr frequency (y 3.00 I.) ( 2.00 li 1.00 O O I 1 000 ( 0 5 10 1, ) — Runoff Hyd - Qp = 2.41 (cfs) Peak discharge (cfs) Time interval (min) Runoff coeff. (C) Tc by User (min) Rec limb factor Friday, Mar 23 2012 = 2.409 = 1 = 0.9 = 10 = 1.00 Hydrograph Volume = 1,446 (cuff); 0.033 (acft) 15 Q (cfs) 3.00 2.00 1.00 '19- 0.00 20 Time (min) i Hydrology Report -, Hydraflow Express Extension for AutoCAD® Civil 3D® 2009 by Autodesk, Inc. Grate Inlet #DS-5 y Hydrograph type ( ) Storm frequency (yrs) -� Drainage area (ac) Rainfall Inten (in/hr) _ OF Curve ly Q (cfs) 2.00 1.00 0.00 -9 0 = Rational = 100 = 0.290 = 11.639 = BrazCnty.IDF 5 Runoff Hyd - Qp = 1.92 (cfs) Runoff Hydrograph 100-yr frequency 10 Peak discharge (cfs) Time interval (min) Runoff coeff. (C) Tc by User (min) Rec limb factor Friday, Mar 23 2012 = 1.924 = 1 = 0.57 = 10 = 1.00 Hydrograph Volume = 1,154 (cult); 0.027 (acft) 15 Q (cfs) 2.00 1.00 x- 0.00 20 Time (min) Inlet Report Hydraflow Express Extension for AUtoCAD® Civil 3DO 2009 by Autodesk, Inc. Friday, Mar 23 2012 Grate Inlet #DS-4 NOTE: 0IS 125% OF ACTUAL FOR CLOGGING Drop Grate Inlet Calculations Location = Sag Compute by: Known Q Curb Length (ft) _ -0- Q (cfs) = 3.01 Throat Height (in) _ -0- Grate Area (sqft) = 1.14 Highlighted Grate Width (ft) = 2.16 Q Total (cfs) = 3.01 Grate Length (ft) = 2.16 Q Capt (cfs) = 3.01 Q Bypass (cfs) _ -0- Gutter Depth at Inlet (in) = 2.90 Slope, Sw (ft/ft) = 0.062 Efficiency (%) = 100 Slope, Sx (ft/ft) = 0.062 Gutter Spread (ft) = 9.95 Local Depr (in) _ -0- Gutter Vel (ft/s) = 3.35 Gutter Width (ft) = 2.16 Bypass Spread (ft) _ -0- Gutter Slope (%) _ -0- Bypass Depth (in) _ -0- Gutter n-value = -0- +mom., er Inlet Report Hydraflow Express Extension for AutoCAD® Civil 31D® 2009 by Autodesk, Inc. Friday, Mar 23 2012 Grate Inlet #DS-5 NOTE: 0 IS 125% OF ACTUAL FOR CLOGGING Drop Grate Inlet Calculations Location = Sag Compute by: Known Q Curb Length (ft) _ -0- Q (cfs) = 2.40 Throat Height (in) _ -0- Grate Area (sqft) = 1.14 Highlighted Grate Width (ft) = 2.16 Q Total (cfs) = 2.40 Grate Length (ft) = 2.16 Q Capt (cfs) = 2.40 Q Bypass (cfs) _ -0- Gutter Depth at Inlet (in) = 2.45 Slope, Sw (ft/ft) = 0,250 Efficiency (%) = 100 Slope, Sx (ft/ft) = 0.250 Gutter Spread (ft) = 3.80 Local Depr (in) _ -0- Gutter Vel (ft/s) = 3.35 Gutter Width (ft) = 2.16 Bypass Spread (ft) _ -0- Gutter Slope (%) _ -0- Bypass Depth (in) _ -0- Gutter n-value = -0- y Hydrology Report �y I Hydraflow Express Extension for AutoCAD® Civil 3138 2009 by Autodesk, Inc. Grate Inlet #DS-6 -D Hydrograph type = Rational ti Storm frequency (yrs) = 100 i Drainage area (ac) = 0.248 Rainfall Inten (in/hr) = 11.639 OF Curve = BrazCnty.IDF i f � I Runoff Hydrograph 4 Q (cfs) 100-yr frequency V vv 0 5 10 — Runoff Hyd - Qp = 2.60 (cfs) 9 Peak discharge (cfs) Time interval (min) Runoff coeff. (C) Tc by User (min) Rec limb factor Friday, Mar 23 2012 = 2.598 = 0.9 = 10 = 1.00 Hydrograph Volume = 1,559 (cuft); 0.036 (acft) 15 Q (cfs) 3.00 2.00 1.00 gel 11 20 Time (min) Inlet Report Hydraflow Express Extension for AutoCAD® Civil 3D® 2009 by Autodesk, Inc. Friday, Mar 23 2012 Grate Inlet #DS-6 NOTE: 0 IS 125% OF ACTUAL FOR CLOGGING Drop Grate Inlet Calculations Location = Sag Compute by: Known Q Curb Length (ft) = -0- Q (cfs) = 3.25 Throat Height (in) = -0- Grate Area (sqft) = 1.14 Highlighted Grate Width (ft) = 2.16 Q Total (cfs) = 3.25 Grate Length (ft) = 2.16 Q Capt (cfs) = 3.25 Q Bypass (cfs) = -0- Gutter Depth at Inlet (in) = 3.38 Slope, Sw (ft/ft) = 0.063 Efficiency (%) = 100 Slope, Sx (ft/ft) = 0.063 Gutter Spread (ft) = 11.10 Local Depr (in) = -0- Gutter Vel (ft/s) = 3.35 Gutter Width (ft) = 2.16 Bypass Spread (ft) = -0- Gutter Slope (%) = -0- Bypass Depth (in) = -0- Gutter n-value = -O- STORM DRAIN LINE DESIGN Scenario: Base WE RENT STORAGE DS-3 DS-1 DS-5 6 DS-6 O UTFALL Title: We Rent Storage Project Engineer: Michael G. Hester, P.E. c:\...\stormsewer\wrs storm sewer stormcad.stm Hester Engineering Company StormCAD v5.5 [5.5003] 03/23/12 11:48:02 AM ©Haestad Methods, Inc. 37 Brookside Road Waterbury, CT 06708 USA +1-203-755-1666 Page 1 of 1 Calculation Results Summary Scenario: Base »» Info: Subsurface Network Rooted by: OUTFALL »» Info: Subsurface Analysis iterations: 2 »» Info: Convergence was achieved. CALCULATION SUMMARY FOR SURFACE NETWORKS note: INLET CAPACITY DETERMINED IN PREVIOUS SECTION Label Inlet Inlet Total I Total Capture Gutter I Gutter Type Intercepted Bypassed Efficiency Spread Depth Flow Flow M (ft) (ft) (cfs) I------------- (cfs) DS-2 --------------- Generic Inlet ---------------------- Generic Default 100% 3.45 ---------- 0.00 ------------ 100.0 -------- 0.00 I________ 0.00 DS-1 Generic Inlet Generic Default 100% 2.13 0.00 100.0 0.00 I 0.00 DS-4 Generic Inlet Generic Default 100% 2.42 0.00 100.0 0.00 0.00 DS-3 Generic Inlet Generic Default 100% 4.32 0.00 100.0 0.00 0.00 DS-6 Generic Inlet Generic Default 100% 2.62 0.00 100.0 0.00 0.00 DS-5 Generic Inlet Generic Default 100% 1.78 0.00 100.0 0.00 0.00 CALCULATION SUMMARY FOR SUBSURFACE NETWORK WITH ROOT: OUTFALL Label Number Section Section Length Total I Average Hydraulic Hydraulic of Size Shape (ft) System Velocity Grade Grade Sections Flow (ft/s) Upstream Downstream I (cfs) (ft) I----------- (ft) I P-2 ---------- 1 --------- 24 inch I---------- Circular -------- 141.33 -------- 16.27 ---------- 6.24 255.55 ____________I 254.75 P-6 l 18 inch Circular 50.00 4.35 4.26 256.11 256.05 P-4 1 18 inch Circular 50.00 6.62 5.08 I 256.21 256.05 P-1 1 12 inch Circular 182.47 2.13 4.42 256..92 256.05 P-5 1 12 inch Circular 38.63 1.78 2.27 256.69 256.61 P-3 l 18 inch Circular 66.21 4.32 2.44 256.80 256.71 Label Total Ground Hydraulic Hydraulic System Elevation Grade Grade Flow (ft) Line In Line Out (cfs) (ft) (ft) -----------� ---------------------------- OUTFALL 16.04 258.00 ----------- 253.30 253.30 DS-2 16.27 258.69 256.05 255.55 DS-6 4.35 258.92 256.61 256.11 DS-4 6.62 258.93 256.71 256.21 DS-1 2.13 260.00 258.22 256.92 DS-5 1.78 258.00 257.99 256.69 DS-3 I 4.32 259.00 258.10 256.80 Completed: 03/23/2012 11:45:07 AM Title: We Rent Storage Project Engineer: Michael G. Hester, P.E. c:\...\stormsewer\wrs storm sewer stormcad.stm Hester Engineering Company StormCAD v5.5 [5.5003) 03/23/12 11:45:31 AM 40 Haestad Methods, Inc. 37 Brookside Road Waterbury, CT 06708 USA +1-203-755-1666 Page 1 of 1 Scenario: Base Pipe Report Label Upstream pstream System Total Length onstructec Section Mannings Full elocity Hydraulic Hydraulic System Inlet Inlet Intensity System (ft) Slope Size n Capacity In Grade Grade Flow Time Area CA (in/hr) Flow (ft/ft) lets) (ff/s) Line In Line Out (min) (acres) (acres) (cfs) (ft) (ft) P-1 0.20 0.18 11.64 2.13 182.47 0.007124 12 inch 0.012 3.26 4.14 256.92 256.05 10.00 P-2 0.33 0.29 11.32 16.27 141.33 0.004953 24 inch 0.012 17.25 6.24 255.55 254.75 10.69 P-3 0.41 0.37 11.64 4.32 66.21 0.002266 18 inch 0.012 5.42 2.44 256.80 256.71 10.00 P-4 0.23 0.21 11.43 6.62 50.00 0.005000 18 inch 0.012 8.05 3.77 256.21 256.05 10.45 P-5 0.28 0.15 11.64 1.78 38.63 0.002589 12 inch 0.012 1.96 2.27 256.69 256.61 10.00 P-6 1 0.25 0.22 11.51 4.35 50.00 0.004000 18 inch 0.012 7.20 2.52 256.11 256.05 10.28 Title: We Rent Storage Project Engineer: Michael G. Hester, P.E. c:\...\stormsewer\wrs storm sewer stormcad.stm Hester Engineering Company StormCAD v5.5 [5,5003] 03/23/12 11:47:04 AM ©Haestad Methods, Inc. 37 Brookside Road Waterbury, CT 06708 USA +1-203-755-1666 Page 1 of 1 Scenario: Base Node Report Label Area Inlet Inlet System Time System System System Total Ground Rim HydraulicHydraulic (acres) C CA CA of low TIME Intensity Rational System Elevation Elevation Grade Grade (acres) (acres) oncentratio (min) (in/hr) Flow Flow (ft) (ft) Line In Line Out (min) (cfs) (CIS) (ft) (ft) OUTFAL 1.43 11.06 11.16 16.04 16.04 258.00 257.50 253.30 253.30 DS-2 0.33 0.90 0.29 1.43 10.00 10.69 11.32 16.27 16.27 258.69 258.69 256.05 255.55 DS-1 0.20 0.90 0.18 0.18 10.00 10.00 11.64 2.13 2.13 260.00 258.90 258.22 256.92 DS-4 0.23 0.90 0.21 0.57 10.00 10.45 11.43 6.62 6.62 258.93 258.93 256.71 256.21 DS-3 0.41 0.90 0.37 0.37 10.00 10.00 11.64 1 4.32 4.32 259.00 258.50 258.10 256.80 DS-6 0.25 0.90 0.22 0.38 10.00 10.28 11.51 4.35 4.35 258.921 258.92 256.61 256.11 IDS-5 1 0.28 0.53 0.151 0.15 10.00 1 10.00 1 11.64 1 1.78 1.78 258.00 1258.00 257.99 256.69 Title: We Rent Storage Project Engineer: Michael G. Hester, P.E. c:\...\stormsewer\wrs storm sewer stormcad.stm Hester Engineering Company StormCAD v5.5 [5.5003) 03/23/12 11:49:30 AM ©Haestad Methods, Inc. 37 Brookside Road Waterbury, CT 06708 USA +1-203-755-1666 Page 1 of 1 r lLN 4— O L 4- 0 w w 0 M O O U) LO QLO LON N a E 0 0 O M N J Qw0 LL O M N CO 0rl U� N N � E Jd'(/J v $ O N a1 O It LO QLON "N a J CC Cl) Y Y W co r m V LO QLON ''N O E J d Cl) W 0 0 O LO N 0 0 + Cl) w w O � x M N N w NNUCl) N ` LO Cl)C 0 d > > M V o C C -NO v--�N N DC�NO J Z)Q J(/7(n 0 0 N w w rlV. Lq V Y LO N w NN C0 L LY'CO d v U70 co LO _ > >0,0 C C 0 N aclO NO JQQ J(nCl) w $ 0 LO O 00 LO V LO LO NN UO i.. �. N N v,ON C CN,O _M �O a CLo NO 17QJ(n(n 0 0 + r 0 0 + O c O CO N of N N 7 0 r f0 0 c U ar E o n U ;; rnM w 0 m c N m o w`X a r N N 0 = o a`] M m U N J N ( N � I w m O ^, W (n 1 O m l O to a O L y VJ 1 0 If) 1 ) O O O O N V w O O �06Lo Lo N N a n E -AU) w 4 O (O Nr 06 Iq D LN N a) 'E m =1 J K(n, w 4 M U) OLO U) N N N a E LU O O In N N Q r-O u_OM jlnM Q L N N 0 "E J E(n X" O OM 4:! N Lo� w NN$ V(M N ` ` M C d > > C j O CClN0 O C N Co J7❑J(n Cn u"'.. V 00 Q� Lf)L w NN VO C O 0 N NOop T + > CO,O I j 1100 'NO J O , , (4(n . . V-V- M N Lo Lo N N U 0) o`L � � �v N(M NN C C(O�o y--00 ..o aCM NO U O O R N N 0 N uj F a p `O UN1 N W N ry x�a . C7 ❑ U m o W O � o o N N N O N W O C + m C w U W O a` b 0 n 0 N O + M N D O r O f c U E U W m� `W c_ m w mao c w W c o O o 0 O w = O N N m M C O c w v N W m x 0 The Cities of Bryan and College Station both require storm drainage design to follow these Unified Stormwater Design Guidelines. Paragraph C2 of Section III (Administration) requires submittal of a drainage report in support of the drainage plan (stormwater management plan) proposed in connection with land development projects, both site projects and subdivisions. That report may be submitted as a traditional prose report, complete with applicable maps, graphs, tables and drawings, or it may take the form of a "Technical Design Summary". The format and content for such a summary report shall be in substantial conformance with the description in this Appendix to those Guidelines. In either format the report must answer the questions (affirmative or negative) and provide, at minimum, the information prescribed in the "Technical Design Summary" in this Appendix. The Stormwater Management Technical Design Summary Report shall include several parts as listed below. The information called for in each part must be provided as applicable. In addition to the requirements for the Executive Summary, this Appendix includes several pages detailing the requirements for a Technical Design Summary Report as forms to be completed. These are provided so that they may be copied and completed or scanned and digitized. In addition, electronic versions of the report forms may be obtained from the City. Requirements for the means (medium) of submittal are the same as for a conventional report as detailed in Section III of these Guidelines. Note: Part 1 — Executive Summary must accompany any drainage report required to be provided in connection with any land development project, regardless of the format chosen for said report. Note: Parts 2 through 6 are to be provided via the forms provided in this Appendix. Brief statements should be included in the forms as requested, but additional information should be attached as necessary. Part 1 — Executive Summary Report Part 2 — Project Administration Part 3 — Project Characteristics Part 4 — Drainage Concept and Design Parameters Part 6 — Plans and Specifications Part 6 — Conclusions and Attestation STORMWATER MANAGEMENT TECHNICAL DESIGN SUMMARY REPORT Part 1 — Executive Summary This is to be a brief prose report that must address each of the seven areas listed below. Ideally it will include one or more paragraphs about each item. 1. Name, address, and contact information of the engineer submitting the report, and of the land owner and developer (or applicant if not the owner or developer). The date of submittal should also be included. 2. Identification of the size and general nature of the proposed project, including any proposed project phases. This paragraph should also include reference to applications that are in process with either City: plat(s), site plans, zoning requests, STORMWATER DESIGN GUIDELINES Page 1 of 26 APPENDIX. D: TECH. DESIGN SUMMARY Effective February 2007 As Revised February 2009 or clearing/grading permits, as well as reference to any application numbers or codes assigned by the City to such request. 3. The location of the project should be described. This should identify the Named Regulatory Watershed(s) in which it is located, how the entire project area is situated therein, whether the property straddles a watershed or basin divide, the approximate acreage in each basin, and whether its position in the Watershed dictates use of detention design. The approximate proportion of the property in the city limits and within the ETJ is to be identified, including whether the property straddles city jurisdictional lines. If any portion of the property is in floodplains as described in Flood Insurance Rate Maps published by FEMA that should be disclosed. 4. The hydrologic characteristics of the property are to be described in broad terms: existing land cover; how and where stormwater drains to and from neighboring properties; ponds or wetland areas that tend to detain or store stormwater; existing creeks, channels, and swales crossing or serving the property; all existing drainage easements (or ROW) on the property, or on neighboring properties if they service runoff to or from the property. 5. The general plan for managing stormwater in the entire project area must be outlined to include the approximate size, and extent of use, of any of the following features: storm drains coupled with streets; detention / retention facilities; buried conveyance conduit independent of streets; swales or channels; bridges or culverts; outfalls to principal watercourses or their tributaries; and treatment(s) of existing watercourses. Also, any plans for reclaiming land within floodplain areas must be outlined. 6. Coordination and permitting of stormwater matters must be addressed. This is to include any specialized coordination that has occurred or is planned with other entities (local, state, or federal). This may include agencies such as Brazos County government, the Brazos River Authority, the Texas A&M University System, the Texas Department of Transportation, the Texas Commission for Environmental Quality, the US Army Corps of Engineers, the US Environmental Protection Agency, et al. Mention must be made of any permits, agreements, or understandings that pertain to the project. 7. Reference is to be made to the full drainage report (or the Technical Design Summary Report) which the executive summary represents. The principal elements of the main report (and its length), including any maps, drawings or construction documents, should be itemized. An example statement might be: "One page drainage report dated , one set of construction drawings (_____sheets) dated and a -page specifications document dated comprise the drainage report for this project." STORMWATER DESIGN GUIDELINES Page 2 of 26 APPENDIX. D: TECH, DESIGN SUMMARY Effective February 2007 As Revised February 2009 SECTION DESIGNAPPENDIX D — TECHNICAL Part 2 — Project Administration Start (Page 2.1) Engineeringand Design Profession aIs;Information Engineering Firm Name and Address: Jurisdiction NESTER ENGINEERING COMPANY City: Bryan 7607 EASTMARK DRIVE, SUITE 253-B X College Station 9 Date of Submittal: COLLEGE STATION, TEXAS 77840 3-22-12 Lead Engineer's Name and Contact Info.(phone, e-mail, fax): Other: MICHAEL G. NESTER, P.E. 979-693-1100 mhester@hester-engr.com Supporting Engineering / Consulting Firm(s): Other contacts: Developer/ Owner / Applicant Information Developer / Applicant Name and Address: Phone and e-mail: ALTON OFCZARZAK, MANAGING MEMBER TOG MANAGEMENT, LR 979-690-1504 4060 HIGHWAY 6 SOUTH, COLLEGE STATION, TX 77840 monica@oakchb.com Property Owner(s) if not Developer / Applicant (& address): Phone and e-mail: Project Identification Development Name: Is subject property a site project, a single-phase subdivision, or part of a multi -phase subdivision? SITE PROJECT If multi -phase, subject property is phase of Legal description of subject property (phase) or Project Area: (see Section II, Paragraph B-3a) WE RENT STORAGE BLOCK 1 LOT 1 If subject property (phase) is second or later phase of a project, describe general status of all earlier phases. For most recent earlier phase Include submittal and review dates. General Location of Project Area, or subject property (phase): INTERSECTION OF HORSE HAVEN LANE AND APPOMATTOX DRIVE In City Limits? Extraterritorial Jurisdiction (acreage): Bryan: acres. Bryan: College Station: College Station: 2.6 acres. Acreage Outside ETJ: STORMWATER DESIGN GUIDELINES Page 3 of 26 APPENDIX. D: TECH. DESIGN SUMMARY Effective February 2007 As Revised February 2009 Part 2 — Project Administration Continued (page 2.2) Project Identification (continued) Roadways abutting or within Project Area or Abutting tracts, platted land, or built subject property: developments: HORSE HAVEN LANE HORSE HAVEN PHASE THREE HORSE HAVEN PHASE ONE (ACADEMY) Named Regulatory Watercourse(s) & Watershed(s): Tributary Basin(s): WOLF PEN CREEK Plat Information For Project or Subject Property (or Phase) Preliminary Plat File #: 12-00500033 Final Plat File #: #12-00500033 Date: Name: WE RENT STORAGE Status and Vol/Pg: PENDING If two plats, second name: File #: Status: Date: Zoning Information For Project or Subject Property (or Phase) Zoning Type: POD Existing or Proposed? Case Code: Case file #11-0 Case Date AUGUST 2011 Status: Zoning Type: Existing or Proposed? Case Code: Case Date Status: Stormwater Management Planning For Project or Subject Property (or Phase) ! Planning Conference(s) & Date(s): Participants: NA Preliminary Report Required? Submittal Date Review Date Review Comments Addressed? Yes _ No _ In Writing? When? Compliance With Preliminary Drainage Report. Briefly describe (or attach documentation explaining) any deviation(s) from provisions of Preliminary Drainage Report, if any. STORMWATER DESIGN GUIDELINES Page 4of 26 APPENDIX. D: TECH. DESIGN SUMMARY Effective February 2007 As Revised February 2009 1500112 Part 2 — Project Administration Continued (page 2.3) Coordination For Project or Subject Property (or Phase) Note: For any Coordination of stormwater matters indicated below, attach documentation describing and substantiating any agreements, understandings, contracts, or approvals. —Dept. Contact: Date: Subject: Coordination With Other NA Departments of Jurisdiction City (Bryan or College Station) Coordination With Summarize need(s) & actions taken (include contacts & dates): Non jurisdiction City Needed? Yes —No X Coordination with Summarize need(s) & actions taken (include contacts & dates): Brazos County Needed? Yes No X Coordination with Summarize need(s) & actions taken (include contacts & dates): TxDOT Needed? Yes No X Coordination with Summarize need(s) & actions taken (include contacts & dates): TAMUS Needed? Yes No X Permits For Projector Subject Property (or Phase) As to stormwater management, are permits required for the proposed work from any of the entities listed below? If so, summarize status of efforts toward that objective ins aces below. Entity Permitted or Approved ? Status of Actions (include dates) US Army Crops of Engineers No X Yes — US Environmental Protection Agency No X Yes _ Texas Commission on Environmental Quality No X Yes Brazos River Authority No X Yes STORMWATER DESIGN GUIDELINES Page 5 of 26 APPENDIX, D: TECH. DESIGN SUMMARY Effective February 2007 As Revised February 2009 Part 3 — Property Characteristics Start (Page 3.1) Nature and Scope of Proposed Work Existing: Land proposed for development currently used, including extent of impervious cover? 2.6 ACRE VACANT LOT - VEGEATIVE COVER Site — Redevelopment of one platted lot, or two or more adjoining ID atted lots. Development _ Building on a single platted lot of undeveloped land. Project _ Building on two or more Platted adjoining lots of undeveloped land. (select all applicable) X Building on a single lot, or adjoining lots, where proposed plat will not form a new street (but may include ROW dedication to existing streets). Other (explain): Subdivision _ Construction of streets and utilities to serve one or more platted lots. Development Construction of streets and utilities to serve one or more proposed lots on Project lands represented by pending plats. Site Proiects: building use(s), approximate floor space, impervious cover ratio. Describe Subdivisions: number of lots by general type of use, linear feet of streets and Nature and drainage easements or ROW. Size of Proposed PERSONAL STORAGE FACILITY 35,000 SQUARE FEET 1.81/2.6 = 0.7 Project Is any work planned on land that is not platted If yes, explain: or on land for which platting is not pending? X No Yes FEMA Floodplains Is any part of subject property abutting a Named Regulatory Watercourse No Yes X (Section II, Paragraph B1) or a tributary thereof? — Is any part of subject property in floodplain No Yes X Rate Map 163C area of a FEMA-regulated watercourse? — — Encroachment(s) into Floodplain Encroachment purpose(s): — Building site(s) _ Road crossing(s) areas planned? Utility crossing(s) —Other (explain): No X Yes If floodplain areas not shown on Rate Maps, has work been done toward amending the FEMA- approved Flood Study to define allowable encroachments in proposed areas? Explain. FLOODPLAIN IS SHOWN ON FLOOD STUDY STORMWATER DESIGN GUIDELINES Page 6 of 26 APPENDIX. D: TECH. DESIGN SUMMARY Effective February 2007 As Revised February 2009 Part 3 — Property Characteristics Continued (Page 3.2) Hydrologic Attributes of Subject Property (or Phase) Has an earlier hydrologic analysis been done for larger area including subject property? Yes Reference the study (& date) here, and attach copy if not already in City files. Is the stormwater management plan for the property in substantial conformance with the earlier study? Yes No If not, explain how it differs. No If subject property is not part of multi -phase project, describe stormwater management X plan for the property in Part 4. If property is part of multi -phase project, provide overview of stormwater management plan for Project Area here. In Part 4 describe how plan for subject property will comply therewith. Do existing topographic features on subject property store or detain runoff? _ No _ Yes Describe them (include approximate size, volume, outfall, model, etc). Any known drainage or flooding problems in areas near subject property? X No _ Yes Identify: Based on location of study property in a watershed, is Type 1 Detention (flood control) needed? (see Table B-1 in Appendix B) Detention is required. _ Need must be evaluated. X Detention not required. What decision has been reached? By whom? If the need for How was determination made? Type 1 Detention must be evaluated: STORMWATER DESIGN GUIDELINES Page 7 of 26 APPENDIX. D: TECH. DESIGN SUMMARY Effective February 2007 As Revised February 2009 Part 3 — Property Characteristics Continued (Page 3.3) Hydrologic Attributes of Subject Property (or Phase) (continued),i Does subject property straddle a Watershed or Basin divide? X No Yes If yes, describesplits below. In Part 4 describe design conce t for handling this. Watershed or Basin Larger acreage Lesser acreage Above -Project Areas(Section II, Paragraph B3-a) Does Project Area (project or phase) receive runoff from upland areas? X No _ Yes Size(s) of area(s) in acres: 1) 2) 3) 4) Flow Characteristics (each instance) (overland sheet, shallow concentrated, recognizable concentrated section(s), small creek (non -regulatory), regulatory Watercourse or tributary); Flow determination: Outline hydrologic methods and assumptions: Does storm runoff drain from public easements or ROW onto or across subject property? No Yes If yes, describe facilities in easement or ROW: Are changes in runoff characteristics subject to change in future? Explain Conveyance Pathways (Section Il, Paragraph C2) Must runoff from study property drain across lower properties before reaching a Regulatory Watercourse or tributary? No X Yes Describe length and characteristics of each conveyance pathway(s). Include ownership of property(ies). THE OUTFALL OF THE PROPOSED STORM DRAIN LINE DISCHARGES INTO AN EXISTING CREEK THAT FLOWS INTO A SMALL TANK THAT DISHCARGES INTO WOLF PEN CREEK. THE LAND TO THE DISCHARGE OF THE TANK IS OWNED BY THE OWNER (650'). THE LAND BETWEEN THE TANK AND WOLF PEN CREEK IS OWNED BY THE CoCS (130'). STORMWATER DESIGN GUIDELINES Page 8 of 26 APPENDIX. D: TECH. DESIGN SUMMARY Effective February 2007 As Revised February 2009 Part 3 — Property Characteristics I Continued (Page 3.4) Hydrologic Attributes of Subject Property (or Phase) (continued) Conveyance Pathways (continued) Do drainage If yes, for what part of length? 90 % Created by? _ plat, or easements instrument. If instrument(s), describe their provisions. exist for any part of pathway(s)? THERE IS A DRAINAGE AND CONSERVATION EASEMENT THAT DUMPS INTO A VARIABLE WIDTH DRAINAGE AND CONSERVATION EASEMENT —No X Yes 4107/07. Where runoff must cross lower properties, describe characteristics of abutting lower property(ies). (Existing watercourses? Easement or Consent squired?) Pathway THE LOWER PROPERTY IS OWNED BY THE OWNER AND A STRIP OF Areas APPROXIMATELY 130 FEET BETWEEN THE OUTFALL OF THE TANK AND THE CENTERLINE OF WOLF PEN CREEK IS OWNED BY THE CITY AS A GREENWAY. Describe any built or improved drainage facilities existing near the property (culverts, bridges, lined channels, buried conduit, swales, detention ponds, etc). THE DRAINAGE AND CONSERVATION EASEMENT SOUTH OF THE TRACT HAS A DITCH ALONG IT AND THE VARIABLE WIDTH DRAINAGE AND CONSERVATION EASEMENT HAS A TANK. ALL OF THIS AREA IS IN THE FLOODPLAIN. Nearby Drainage Facilities Do any of these have hydrologic or hydraulic influence on proposed stormwater design? X No _Yes If yes, explain: STORMWATER DESIGN GUIDELINES Page 9 of 26 APPENDIX. D: TECH. DESIGN SUMMARY Effective February 2007 As Revised February 2009 Part 4 — Drainage Concept and Design Parameters Start (Page 4.1) Stonnwater Management Concept Discharge(s) From Upland Area(s) If runoff is to be received from upland areas, what design drainage features will be used to accommodate it and insure it is not blocked by future development? Describe for each area, flow section, or discharge point. NA Discharge(s) To Lower Property(ies) (Section 11, Paragraph E1) Does project include drainage features (existing or future) proposed to become public via platting? X No Yes Separate Instrument? No Yes Per Guidelines reference above, how will Establishing Easements (Scenario 1) runoff be discharged to neighboring "— Pre -development Release (Scenario 2) property(ies)? NA Combination of the two Scenarios Scenario 1: If easements are proposed, describe where needed, and provide status of actions on each. (Attached Exhibit # ) Scenario 2: Provide general description of how release(s) will be managed to pre -development conditions (detention, sheet flow, partially concentrated, etc.). (Attached Exhibit # ) THE OUTFALL FROM THE STORM DRAIN SYSTEM WILL DISCHARGE INTO AN EXISTING CREEK. Combination: If combination is proposed, explain how discharge will differ from pre - development conditions at the property line for each area (or point) of release. If Scenario 2, or Combination are to be used, has proposed design been coordinated with owner(s) of receiving property(ies)? No _ Yes Explain and provide documentation. STORMWATER DESIGN GUIDELINES Page 10 of 26 APPENDIX. D: TECH. DESIGN SUMMARY Effective February 2007 As Revised February 2009 Part 4 — Drainage Concept and Design Parameters Continued (Page 4.2) Stormwater Management Concept (continued)` Within Protect Area Of Multi -Phase Project Identify gaining Basins or Watersheds and acres shifting: Will project result in shifting runoff between Basins or between What design and mitigation is used to compensate for increased runoff Watersheds? from gaining basin or watershed? X No Yes How will runoff from Project 1. _ With facility(ies) involving other development projects. Area be mitigated to pre- development conditions? 2 Establishing features to serve overall Project Area. — Select any or all of 1, 2, 3. On phase (or site) project basis within Project Area. and/or 3, and explain below. 1. Shared facility (type & location of facility; design drainage area served; relationship to size of Project Area): (Attached Exhibit # ) NA 2. For Overall Project Area (type & location of facilities): (Attached Exhibit #) 3. By phase (or site) project: Describe planned mitigation measures for phases (or sites) in subsequent questions of this Part. Are aquatic echosystems proposed? X No —Yes In which phase(s) or project(s)? C' N Are other Best Management Practices for reducing stormwater pollutants proposed? o No X Yes Summarize type of BMP and extent of use: m c N - SEDIMENT CONTROL WITH SILT FENCING DURING CONSTRUCTION AND UNTIL o 0 A HEALTHY GROUND COVER IS ESTABLISHED. X If design of any runoff -handling facilities deviate from provisions of B-CS Technical a Specifications, check type facility(ies) and explain in later questions. _ Detention elements Conduit elements Channel features Swales , Ditches _ Inlets — Valley gutters _ Outfalls Culvert features _ Bridges Other STORMWATER DESIGN GUIDELINES Page t 1 of 26 APPENDIX. D: TECH, DESIGN SUMMARY Effective February 2007 As Revised February 2009 Part 4 — Drainage Concept and Design Parameters I Continued (Page 4.3) Storrnwater Management Concept (continued); Within Protect Area Of Multi -Phase Project (continued) Will Project Area include bridge(s) or culvert(s)? No Yes Identify type and general size and In which phase(s). If detention/retention serves (will serve) overall Project Area, describe how it relates to subject phase or site project (physical location, conveyance pathway(s), construction sequence): NA Within Or Serving Subject Property (Phase, or Site) If property part of larger Project Area, is design in substantial conformance with earlier analysis and report for larger area? ` Yes No, then summarize the difference(s): NA Identify whether each of the types of drainage features listed below are included, extent of use, and general characteristics. Typical shape? Surfaces? C v 0 0 Steepest side slope Steepest side slopes: Usual front slopes: Usual back slopes: N } 7 m Flow line slopes: least Typical distance from travelway: `moo typical greatest (Attached Exhibit # ) o — z o X I Are longitudinal culvert ends in compliance with B-CS Standard Specifications? T Yes No, then explain: At intersections or otherwise, do valley gutters cross arterial or collector streets? ��•� No Yes If yes explain: U� s V) N(D Are valley gutters proposed to cross any street away from an intersection? o,z No _Yes Explain: (number of locations?) N � N NXI Q STORMWATER DESIGN GUIDELINES Page 12 of 26 APPENDIX. D: TECH. DESIGN SUMMARY Effective February 2007 As Revised February 2009 Part 4 — Drainage Concept and Design Parameters Continued (Page 4.4) Storrnwater Management Concept (continued) Within Or Serving Subject Property (Phase, or Site) (continued) Gutter line slopes: Least Usual Greatest Are inlets recessed on arterial and collector streets? Yes No If "no", identify where and why. Will inlets capture 10-year design stormflow to prevent flooding of intersections (arterial with arterial or collector)? __ Yes No If no, explain where and why not. r v d Will inlet size and placement prevent exceeding allowable water spread for 10-year a) design storm throughout site (or phase)? _ Yes No If no, explain. rn Sag curves: Are inlets placed at low points? Yes No Are inlets and conduit sized to prevent 100-year stormflow from ponding at greater than 24 inches? r 0 _ Yes _ No Explain "no" answers. L° m d C Will 100-yr stormflow be contained in combination of ROW and buried conduit on whole length of all streets? , Yes No If no, describe where and why. Do designs for curb, gutter, and inlets comply with B-CS Technical Specifications? Yes _ No If not, describe difference(s) and attach justification. Are any 12-inch laterals used? _ No X Yes Identify length(s) and where used. 185 & 40 LINEAR FEET PRIVATE DRAINAGE SYSTEM C1 NPipe runs between system Typical 60 Longest 184 M 8 access points (feet): d X Are junction boxes used at each bend? Yes X No If not, explain where Nand I why. a z° GRATE INLET WILL BE USED IN PLACE OF JUNCTION BOXES, PRIVATE DRAINAGE SYSTEM N Are downstream soffits at or below upstream soffits? Least amount that hydraulic w — Yes X No If not, explain where and why: grade line is below gutter line (system -vide): 0.5 FEET STORMWATER DESIGN GUIDELINES Page 13 of 26 APPENDIX. D: TECH. DESIGN SUMMAR` Effective February 2007 As Revised February 2009 Part 4 - Drainage Concept and Desian Parameters Continued (Page 4.5) Stormwater Management Concept (continued) Within Or Serving Subject Property (Phase, or Site) (continued) Describe watercourse(s), or system(s) receiving system discharge(s) below a)(include design discharge velocity, and angle between converging flow lines). 0 1) Watercourse (or system), velocity, and angle? RAINAGE m WOLF PEN CREEK, THE PRIVATE SYSTEM O TFALL STRUCTURE FLOWLINE IS ABOVE THE FLOODPLAIN SO THERE WILL BE NO TAIL WATER EFFECT AND THERE IS A DROP IN THE STRUCTURE 0 FOR ENERGY DISSIPATION & ROCK RIP RAP, ANGLE IS 90 DEGREES. E 2) Watercourse (or system), velocity, and angle? c a c0� cd aE E 3) Watercourse (or system), velocity, and angle? T N 'G N N c P � 0 o v` a E For each outfall above, what measures are taken to prevent erosion or scour of Nreceiving and all facilities at juncture? w 1) SEE ABOVE m `m a 2) w a 0 3) Are swale(s) situated along property lines between properties? X No _ Yes Number of instances: For each instance answer the following questions. Surface treatments (including low -flow flumes if any): THE PRIVATE DRIVES WILL HAVE GRATE INLETS N } Flow line slopes (minimum and maximum): 0.5% 0 X 0 Z Ouffall characteristics for each (velocity, convergent angle, & end treatment). ALL DRIVEWAYS DISCHARGE INTO GRATE INLET OR THE OUTFALL STRUCTURE IS A RECESSED INLET. y` Will 100-year design storm runoff be contained within easement(s) or platted drainage ROW in ail instances? _Yes _ No If"no" explain: THE PRIVEATE STORM DRAIN SYSTEM IS DESIGNED FOR Q100 & THE DRIVEWAYS ARE DESIGNED TO OVERFLOW TO THE SOUTH OF THE PROPERTY IF A GRATE INLETS IS 100 PERCENT CLOGGED. STORMWATER DESIGN GUIDELINES Page 14 of 26 APPENDIX. D: TECH, DESIGN SUMMARY Effective February 2007 As Revised February 2009 Im Part 4 — Drainage Concept and Design Parameters Continued (Page 4.6) Stormwater Management Concept (continued); Within Or Serving Subject Property (Phase, or Site) (continued) Are roadside ditches used? X No Yes If so, provide the following: 0) Is 25-year flow contained with 6 inches of freeboard throughout ? _ Yes _ No Are top of banks separated from road shoulders 2 feet or more? —Yes _ No m Are all ditch sections trapezoidal and at least 1.5 feet deep? _ Yes No N For any "no" answers provide location(s) and explain: v 0 0 K If conduit is beneath a swale, provide the following information (each instance). Instance 1 Describe general location, approximate length: Is 100-year design flow contained in conduit/swale combination? —Yes —No (� If "no" explain: 0 m Space for 100-year storm flow? ROW _ Easement— Width Z c Swale Surface type, minimum Conduit Type and size, minimum and maximum X I and maximum slopes: slopes, design storm: 0 N 'o c Inlets Describe how conduit is loaded (from streets/storm drains, inlets by type): c M m L M U C 0 o Access Describe how maintenance access is provided (to swale, into conduit): 6 10 E — c .E Instance 2 Describe general location, approximate length: N E N � c v Is 100-year design flow contained in conduit/swale combination? —Yes —No 0 'o If "no" explain: 10 S. c E a) Space for 100-year storm flow? ROW _ Easement _ Width v Swale Surface type, minimum I Conduit Type and size, minimum and maximum mand maximum slopes: slopes, design storm: WInlets Describe how conduit is loaded (from streets/storm drains, inlets by type): Access Describe how maintenance access is provided to Swale, into conduit �_ p ( Y STORMWATER DESIGN GUIDELINES Page 15 of 26 APPENDIX. D: TECH. DESIGN SUMMARY Effective February 2007 As Revised February 2009 Part 4 — Drainage Concept and Design Parameters I Continued (Page 4.7) Stormwater Management Concept (continued); Within Or Serving Subject Property (Phase, or Site) (continued) If 'yes" provide the following information for each instance: Instance 1 Describe general location, approximate length, surfacing: CL o W 4-- Is 100-year design flow contained in swale? Yes _ No Is swale wholly within drainage ROW? No Explain "no" answers: —Yes a� Access Describe how maintenance access is provide: d) o Z v c X 0 Instance 2 Describe general location, approximate length, surfacing: v n � c w o E L N Is 100-year design flow contained in swale? Yes No Is swale wholly `o within drainage ROW? Yes No Explain "no" answers: _N O _ _ N W Access Describe how maintenance access is provided: 5. U_ 3 a Instance 3.4. etc. If swales are used in more than two instances, attach sheet providing all above information for each instance. "New" channels: Will any area(s) of concentrated flow be channelized (deepened, widened, or straightened) or otherwise altered? _ No Yes if only slightly shaped, see "Swales" in this Part. If creating side banks, provide information below. $ c Will design replicate natural channel? Yes No If"no", for each instance $ o describe section shape & area, flow line slope (min. & max.), surfaces, and 100-year CL o W design flow, and amount of freeboard: d Instance 1: c } E E o Instance 2: E o — z XI Instance3: s U STORMWATER DESIGN GUIDELINES Page 16 of 26 APPENDIX. D: TECH. DESIGN SUMMARY Effective February 2007 As Revised February 2009 Part 4 — Drainage Concept and Design Parameters Continued (Page 4.8) Storrnwater Management Concept (continued)' Within Or Serving Subject Property (Phase, or Site) (continued) Existing channels (small creeks): Are these used? No Yes _ If" es" provide the information below. Will small creeks and their floodplains remain undisturbed? Yes No How many disturbance instances? _ Identify each planned location: For each location, describe length and general type of proposed improvement (including floodplain changes): For each location, describe section shape & area, flow line slope (min. & max.), surfaces, and 100-year design flow. NA c .o Watercourses (and tributaries): Aside from fringe changes, are Regulatory 0 Watercourses proposed to be altered? No Yes Explain below. _ 42 Submit full report describing proposed changes to Regulatory Watercourses. Address E existing and proposed section size and shape, surfaces, alignment, flow line changes, > length affected, and capacity, and provide full documentation of analysis procedures ° and data. Is full report submitted? Yes No If "no" explain: a E _ d c c UAll Proposed Channel Work: For all proposed channel work, provide information requested in next three boxes. If design is to replicate natural channel, identify location and length here, and describe design in Special Design section of this Part of Report. Will 100-year flow be contained with one foot of freeboard? —Yes —No if not, identify location and explain: Are ROW / easements sized to contain channel and required maintenance space? Yes _ No If not, identify location(s) and explain: STORMWATER DESIGN GUIDELINES Page 17of26 APPENDIX. D: TECH. DESIGN SUMMARY Effective February 2007 As Revised February 2009 diixN:111[a_1�a7�^tCrl:F � u _ Part 4 — Drainage Concept and Design Parameters Continued (Page 4.9) Stormwater Management Concept (continued)` Within Or Serving Subject Property (Phase, or Site) (continued) How many facilities for subject property project? For each provide info. below. For each dry -type facilitiy: Facility 1 Facility 2 Acres served & design volume + 10% 100-yr volume: free flow & plugged Design discharge (10 yr & 25 yr) Spillway crest at 100-yr WSE? _ yes _ no —yes no a Berms 6 inches above plugged WSE? _ yes _ no _ yes no Explain any "no" answers: r For each facility what is 25-yr design Q, and design of outlet structure? Facility 1: 0 Z Facility 2: X Do outlets and spillways discharge into a public facility in easement or ROW? Facility 1: —Yes —No Facility 2: _Yes _No If "no" explain: CL 0 0 0- For each, what is velocity of 25•yr design discharge at outlet? & at spillway? Facility 1: & Facility 2: & ca Are energy dissipation measures used? No _ Yes Describe type and u_ location: c 0 w v 2 For each, is spillway surface treatment other than concrete? Yes or no, and describe: Facility 1: Facility 2: For each, what measures are taken to prevent erosion or scour at receiving facility? Facility 1: Facility 2: If berms are used give heights, slopes and surface treatments of sides. Facility 1: Facility 2: STORMWATER DESIGN GUIDELINES Page 1S of 26 APPENDIX. D: TECH. DESIGN SUMMARY Effective February 2007 As Revised February 2009 Part 4 — Drainage Concept and Desgan Parameters I Continued (Page 4.10) Stormwater Management Concept (continued) Within Or Serving Subject Property (Phase, or Site) (continued) Do structures comply with B-CS Specifications? Yes or no, and explain if "no": Facility 1; w LL Facility 2: c C o c c o For additional facilities provide all same information on a separate sheet. Are parking areas to be used for detention? _ No Yes What is maximum depth due to required design storm? Roadside Ditches: Will culverts serve access driveways at roadside ditches? —No _Yes If "yes", provide information in next two boxes. Will 25-yr. flow pass without flowing over driveway in all cases? _ Yes _ No Without causing flowing or standing water on public roadway? _Yes _ No Designs & materials comply with B-CS Technical Specifications? _ Yes _ No Explain any "no" answers: C' rn c o Are culverts parallel to public roadway alignment? _ Yes _ No Explain: U 1r .- z g Creeks at Private Drives: Do private driveways, drives, or streets cross drainage m ways that serve Above -Project areas or are in public easements/ ROW? 4) z° No Yes If "yes" provide information below. m ' How many instances? Describe location and provide information below. r X > Location 1: U 2 Location 2: a Location 3: For each location enter value for: 1 2 3 Design year passing without toping travelway? Water depth on travelway at 25-year flow? Water depth on travelway at 100-year flow? For more instances describe location and same information on separate sheet. STORMWATER DESIGN GUIDELINES Page 19 of 26 APPENDIX. D: TECH. DESIGN SUMMARY Effective February 2007 As Revised February 2009 Part 4 — Drainage Concept and Design Parameters Continued (Page 4.11) Stomtwater Management Concept (continued) Within Or Serving Subject Property (Phase, or Site) (continued) Named Regulatory Watercourses (& Tributaries): Are culverts proposed on these facilities? No Yes, then provide full report documenting assumptions, criteria, analysis, computer programs, and study findings that support proposed design(s). Is report provided? —Yes —No If "no", explain: Arterial or Major Collector Streets: Will culverts serve these types of roadways? N_ No Yes How many instances? For each identify the v _ location and provide the information below. } Instance 1: 0 Instance 2: c o Instance 3: c 0 z 'E Yes or No for the 100-year design flow. 1 2 3 Headwater WSE 1 foot below lowest curb top? d Xo .9 E Spread of headwater within ROW or easement? n a rn Is velocity limited per conditions (Table C-11)? Explain any "no" answer(s): 2 0 U T o n Minor Collector or Local Streets: Will culverts serve these types of streets? o No Yes How many instances? for each identify the v location and provide the information below: a� Instance 1: Nc Instance 2: m o Instance 3: m For each instance enter value, or "yes" / "no" for: 1 2 3 c o m W 0 Design yr. headwater WSE 1 ft. below curb top? 100-yr. max. depth at street crown 2 feet or less? E Product of velocity (fps) & depth at crown (ft) = ? Is velocity limited per conditions (Table C-11)9 Limit of down stream analysis (feet)? Explain any "no" answers: STORMWATER DESIGN GUIDELINES Page 20 of 26 APPENDIX. D: TECH. DESIGN SUMMARY Effective February 2007 As Revised February 2009 M it =Lbi0ILILOU a IT, Part 4 — Drainage Concept and Design Parameters Continued (Page 4.12) Stormwater Management Concept (continued) Within Or Serving Subject Property (Phase, or Site) (continued) All Proposed Culverts: For all proposed culvert facilities (except driveway/roadside ditch intersects) provide information requested in next eight boxes. Do culverts and travelways intersect at 90 degrees? _ Yes No If not, identify location(s) and intersect angle(s), and justify the design(s): Does drainage way alignment change within or near limits of culvert and surfaced approaches thereto? No _ Yes If "yes" identify location(s), describe change(s), and justification: Are flumes or conduit to discharge into culvert barrel(s)? No Yes If yes, NA _ , identify location(s) and provide justification: Are flumes or conduit to discharge into or near surfaced approaches to culvert ends? No —Yes If "yes" identify location(s), describe outfall design treatment(s): c .c 8 N 0) Is scour/erosion protection provided to ensure long term stability of culvert structural 0 components, and surfacing at culvert ends? Yes —No If "no" Identify locations and provide justification(s): Will 100-yr flow and spread of backwater be fully contained in street ROW, and/or drainage easements/ ROW? _ Yes _ No if not, why not? Do appreciable hydraulic effects of any culvert extend downstream or upstream to neighboring land(s) not encompassed in subject property? No Yes If "yes" describe location(s) and mitigation measures: Are all culvert designs and materials in compliance with B-CS Tech. Specifications? Yes _ No If not, explain in Special Design Section of this Part. STORMWATER DESIGN GUIDELINES Page 21 of 26 APPENDIX. D: TECH. DESIGN SUMMARY Effective February 2007 As Revised February 2009 Part 4 — Drainage Concept and Design Parameters Continued (Page 4.13) Stomtwater Management Concept (continued) Within Or Serving Subject Property (Phase, or Site) (continued) Is a bridge included in plans for subject property project? X No _ Yes If "yes" provide the following information. Name(s) and functional classification of the roadway(s)? What drainage way(s) is to be crossed? rn a m A full report supporting all aspects of the proposed bridge(s) (structural, geotechnical, hydrologic, and hydraulic factors) must accompany this summary report. Is the report provided? —Yes _ No if "no" explain: Is a Stormwater Provide a general description of planned techniques: Pollution Prevention Plan (SW3P) SEDIMENT WILL BE CONTROLLED BY THE INSTALLATION OF Q established for A SILT FENCE ALONG THE WEST & SOUTH SIDES OF THE SITE. 0) project construction? 3� No X Yes Special Designs — Non -Traditional Methods Are any non-traditional methods (aquatic echosystems, wetland -type detention, natural stream replication, BMPs for water quality, etc.) proposed for any aspect of subject property project? X No _ Yes If "yes" list general type and location below. Provide full report about the proposed special design(s) including rationale for use and expected benefits. Report must substantiate that stormwater management objectives will not be compromised, and that maintenance cost will not exceed those of traditional design solution(s). Is report provided? _Yes No If 'no" explain: STORMWATER DESIGN GUIDELINES Page 22 of 26 APPENDIX, D: TECH. DESIGN SUMMARY Effective February 2007 As Revised February 2009 Part 4 — Drainage Concept and Design Parameters Continued (Page 4,14) Stormwater Management Concept (continued); Within Or Serving Subject Property (Phase, or Site) (continued) Special Designs — Deviation From B-CS Technical Specifications If any design(s) or material(s) of traditional runoff -handling facilities deviate from provisions of B-CS Technical Specifications, check type facility(ies) and explain by specific detail element. Detention elements X Drain system elements _ Channel features Culvert features Swales Ditches _ Inlets _Outfalls Valley gutters Bridges (explain in bridge report) In table below briefly identify specific element, justification for deviation(s). Specific Detail Element Justification for Deviation (attach additional sheets if needed) 1) HDPE FOR PRIVATE DRAINAGE SYSTEM 2) 3) 4) 5) Have elements been coordinated with the City Engineer or her/his designee? For each item above provide "yes" or "no", action date, and staff name: 1) NA 2) 3) 4) 5) Design Parameters Hydrology Is a map(s) showing all Design Drainage Areas provided? X Yes No Briefly summarize the range of applications made of the Rational Formula: THE RATIONAL FORMULA IS USED TO DETERMINE STORM RUNOFF TO EACH GRATE INLET. What is the size and location of largest Design Drainage Area to which the Rational Formula has been applied? 0.4 acres Location (or identifier): STORMWATER DESIGN GUIDELINES Page 23 of 26 APPENDIX. D: TECH. DESIGN SUMMARY Effective February 2007 As Revised February 2009 Part 4 — Drainage Concept and Design Parameters Continued (Page 4.15) Design Parameters (continued) Hydrology (continued) In making determinations for time of concentration, was segment analysis used? X No _ Yes In approximately what percent of Design Drainage Areas? % As to Intensity -duration -frequency and rain depth criteria for determining runoff flows, were any criteria other than those provided in these Guidelines used? X No _Yes If "yes" identify type of data, source(s), and where applied: For each of the stormwater management features listed below identify the storm return frequencies (year) analyzed (or checked), and that used as the basis for design. Feature Analysis Year(s) Design Year Storm drain system for arterial and collector streets Storm drain system for local streets Open channels Swale/buried conduit combination in lieu of channel Swales Roadside ditches and culverts serving them Detention facilities: spillway crest and its ouffall Detention facilities: outlet and conveyance structure(s) Detention facilities: volume when outlet plugged Culverts serving private drives or streets Culverts serving public roadways Bridges: provide in bridge report. Hydraulics What is the range of design flow velocities as outlined below? Design flow velocities; Gutters Conduit Culverts Swales Channels Highest (feet per second) 6.24 Lowest (feet per second) 2.27 Streets and Storm Drain Systems Provide the summary information outlined below. Roughness coefficients used: For street gutters: 0.13 CONCRETE For conduit type(s) HDPE Coefficients: 0,12 STORMWATER DESIGN GUIDELINES Page 24 of 26 APPENDIX. D: TECH. DESIGN SUMMAW Effective February 2007 As Revised February 2009 Part 4 — Drainage Concept and Design Parameters Continued (Page 4.16) Design Parameters (continued) Hydraulics (continued) Street and Storm Drain Systems (continued) For the following, are assumptions other than allowable per Guidelines? Inlet coefficients? X No Yes Head and friction losses X No Yes Explain any "yes" answer: In conduit is velocity generally increased in the downstream direction? X Yes _ No Are elevation drops provided at inlets, manholes, and junction boxes? X Yes _ No Explain any "no" answers: Are hydraulic grade lines calculated and shown for design storm? X Yes _ No For 100-year flow conditions? X Yes _ No Explain any "no" answers: What tailwater conditions were assumed at outfall point(s) of the storm drain system? Identify each location and explain: THE DISCHARE OF THE PRIVATE STORM DRAIN LINE INTO THE OUTFALL STRUCTURE IS 1.3 FEET ABOVE THE BASE FLOOD ELEVATION SO THERE WILL BE NO TAIL WATER AFFECT. Open Channels If a HEC analysis is utilized, does it follow Sec VI.F.5.a? Yes _ No Outside of straight sections, is flow regime within limits of sub -critical flow? _ Yes _ No If "no" list locations and explain: Culverts If plan sheets do not provide the following for each culvert, describe it here. For each design discharge, will operation be outlet (barrel) control or inlet control? Entrance, friction and exit losses: Bridges Provide all in bridge report STORMWATER DESIGN GUIDELINES Page 25 of 26 APPENDIX. D: TECH. DESIGN SUMMARY Effective February 2007 As Revised February 2009 Part 4 — Drainage Concept and Design Parameters Continued (Page 4.17) Design Parameters (continued) Computer Software What computer software has been used in the analysis and assessment of stormwater management needs and/or the development of facility designs proposed for subject property project? List them below, being sure to identify the software name and version, the date of the version, any applicable patches and the publisher HAESTAD METHODS STORM CAD, VERSION 5.5 AUTODESK CIVIL 3D 2009 HYDROFLOW STORM SEWER EXTENSION, VERSION 6.066 Part 5 — Plans and Specifications Requirements for submittal of construction drawings and specifications do not differ due to use of a Technical Design Summary Report. See Section III, Paragraph C3. Part 6 — Conclusions and Attestation Conclusions Add any concluding information here: Attestation Provide attestation to the accuracy and completeness of the foregoing 6 Parts of this Technical Design Summary Drainage Report by signing and sealing below. "This report (plan) for the drainage design of the development named in Part 8 was prepared by me (or under my supervision) in accordance with provisions of the Bryan/College Station Unified Drainage Design Guidelines for the owners of the property. All licenses and permits required by any and all state and federal regulatory agencies for the proposed drainage improvements have been issued or fall under applicable general permits." n S �OF Licensed Professional Engineer�� r;MICHAEL G. 4STER State of Texas PE No. 69104 69104 1kiz'c5/CENS �O G��? 'v�1ONAI STORMWATER DESIGN GUIDELINES Page 26 of 26 APPENDIX. D: TECH. DESIGN SUMMARY Effective February 2007 As Revised February 2009 SECTION IX APPENDIX B — REGION'S WATERSHEDS Table B-1 (continued) Detention Requirements by Watershed and Watershed Reach Reference Section II, Paragraph B1, page 2 of 18 Watershed Name Channel Reach Detention For Flood Control From To Steep Hollow Wickson Creek Green Branch Loop, Easterlinq Drive Evaluate Branch Green Branch Loop, Easterling Drive Upstream Required Still Creek Thompsons Creek FM 2818 Evaluate FM 2818 Upstream Required Thompsons Thompsons Creek N. Texas Avenue Evaluate N. Texas Avenue Upstream Required Branch Thompsons Creek Brazos River SH 21 Not Required SH 21 Thompsons Branch te Thompsons Branch U stream Required Brazos River SH 47 uired Turkey Creek SH 47 W. Villa Maria Drive ONot te W. Villa Maria Drive U stream ed Brazos River Unnamed Road off White Creek Road quired White Creek Unnamed Road off White Creek Road FM 2818 Evaluate FM 2818 U stream Required Carter Creek Dartmouth Street Not Required Dartmouth Street George Bush Drive at Texas Avenue Evaluate Wolf Pen Creek George Bush Drive at Texas Avenue I Upstream Required STORMWATER DESIGN GUIDELINES Page 2 of 24 APPENDIX B: REGION'S WATERSHEDS Effective February 2007 As Revised February 2009