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HomeMy WebLinkAboutParkview Christian Church - Stormwater Management CalculationsStormwater Management Calculations for Parkview Christian Church 201 W. Ustick Rd Meridian, Idaho Prepared for Randy Haverfield Architecture Northwest 224 12th Avenue South Nampa, Idaho (208) 467-3377 Prepared by Dallin Warnick Aspen Engineers, Chartered �r �v Date Prepared September 27, 2012 ASPEN ENGINEERS Aspen Engineers, Chartered 2422 12th Ave Rd #323 Nampa, Idaho 83686 Aspen File 13031 Phone(208)466-8181 www. A s p e n E n g n e e rs. cc m P:\2013\13031\Documents\Storm Calcs\RevA\1. Storm Calculation Introduction.doc Stormwater Management Calculations for Parkview Christian Church 201 W. Ustick Rd Meridian, Idaho Table of Contents ASPEN ENGINE.ERS Section and Description Page 1. Project Description............................................................................................................................. 3 2. Sources of Information....................................................................................................................... 3 3. Applicable Standards..........................................................................................................................4 4. Drawing Showing Site Drainage Areas............................................................................................... 5 5. Stormwater Runoff Calculations for Drainage Area#1...................................................................... 6 6. Stormwater Runoff Calculations for Drainage Area#2...................................................................... 8 7. Stormwater Runoff Calculations for Drainage Area #3.................................................................... 10 8. Stormwater Runoff Calculations for Drainage Area#4.................................................................... 12 9. Stormwater Runoff Calculations for Drainage Area #5.................................................................... 14 Appendices A. Runoff Coefficient and Rainfall Intensity..................................................................................2 pages B. Infiltration Rate Information.......................................................................................................1 page C. Sand / Grease Trap Cut Sheet.....................................................................................................1 page PA2013\13031\Documents\Storm Calcs\RevA\1. Storm Calculation Introduction.doc Page 2 Stormwater Management Calculations for Parkview Christian Church 201 W. Ustick Rd Meridian, Idaho 1. Project Description These calculations and attachments provide the background for the design for a new stormwater management system associated with a building additions for Parkview Christian Church located at 201 W. Ustick Rd in Meridian, Idaho. These calculations, together with the associated civil plans are meant to provide information on the proposed size and location of the seepage beds that will be used to manage stormwater runoff from the proposed building and parking lot. The proposed stormwater system will use pavement grading and roof drain lines to direct the stormwater runoff to a series of seepage beds throughout the site. A 1,000 gallon sand / grease trap will be used to help remove sediment and oil prior to entering each seepage bed. The distance between the baffles of the sand / grease trap was selected to keep the velocity of the water below 0.50 ft/sec to help provide residence time so sediment can settle in the trap. The seepage beds were sized to handle the anticipated runoff from the 100 -year, 1 -hour storm event using a combination of internal storage in the drain rock and the calculated percolation volume during the 1 -hour design storm event. The seepage beds will be constructed with drain rock underlain by a 6"-12" layer of ASTM C-33 filter sand. This will help provide some treatment before the stormwater infiltrates into the subsurface as well as promote infiltration into the subsurface. Since no site specific soils report was provided, for the purpose of these calculations an infiltration rate of 2 in/hr was used which is about % of the rate observed for filter sand. The elevation of seasonal high groundwater was estimated to be at 7-10 feet below existing grade based on experience in the surrounding area. 2. Sources of Information The following sources of data were used in preparing these calculations: A. Urban Runoff Control Hondbookfor Ada and Canyon Counties, Idaho Ada/Canyon Waste Treatment Management Committee (January 1977). B. Architectural Site Layout provided by Architecture Northwest (September 2013). P:\2013\13031\Documents\Storm Calcs\RevA\1. Storm Calculation Introduction.doc Page 3 Stormwater Management Calculations for Parkview Christian Church 201 W. Ustick Rd Meridian, Idaho 3. Applicable Standards 0 ASPEN ENGINEERS The following standards were used in preparing these calculations: A. Idaho Standard Public Works Construction Committee. Idaho Standards for Public Works Construction, Current Edition. B. City of Meridian, Ada County, Idaho. Supplementation Specification and Drawings to the Idaho Standards for Public Works Construction. 2008. C. Linsley, Ray, et al, 1992. Water Resources and Environmental Engineering, Fourth Edition, McGraw-Hill, Publishers, Inc. P:\2013\13031\Documents\Storm Calcs\RevA\1. Storm Calculation Introduction.doc Page 4 r w Q d a- 0 N Q W d' Q w Q Z a 0 W I -- V5 v a3: La 1 a LU M .E N V1w U C:) < _. Q c; N N � I � I I M 1 I ii • I III' '� __� .E N V1w U C:) < _. Q c; N N � Project: Parkview Christian Church Subject: Stormwater Runoff Calculations By: L. Warnick Number: r 09/27 �..7 1V Date: 09/27/1300 ENGINEERS Page: (� 5. RUNOFF CALCULATIONS FOR DRAINAGE AREA 1 A. FIND TIME OF CONCENTRATION (tc) Assume: The time of concentration (tc) for this area is defined as the time needed to reach the inlets from the point that is farthest away. It is assumed the time is 10 minutes. B. FIND PEAK DISCHARGE (0) Design Storm 100 -yr, 10 -min Using the Rational Method (Q = CIA) for the 100 -yr, 10 -min storm which is the estimated time of concentration. Given: C Runoff Coefficient 0,95 1 Intensity 3.1 in/hr A Drainage Area 0.27 acres Solution: Q Peak Discharge = C*I*A 0.80 cfs C. FIND FLOW THROUGH DRAIN PIPE Given: Total Area D Pipe Diameter 12 in A Pipe flow area = pi * DA2/4 = 0.79 ftz n Roughness coefficient = 0.009 R Hydraulic Radius = D/4 0.250 feet s Slope = 0.40% Solution: q Flow = [1.49 / n * A * RA2/3 * sA0.5] q Flow = 3.26 cfs Check: Flow (q) > Peak Discharge (Q)? YES D. FIND VELOCITY IN GREASE TRAP (v) Given: Grease Trap Size 1,000 gal wt Trap Width 4.00 ft d Distance Between Baffles 15 in a Flow Area = wt*d 5.00 sf Solution: v Velocity = Q/a 0.16 fps Check: Velocity (v) < 0.5 fps? YES P:\2013\13031\Documents\Storm Calcs\RevA\3. Storm Calcs - 13021 See Appendix A.1 See Appendix A.2 See Page 5 See Appendix C.1 Project: Parkview Christian Church Number: 13031 ASPEN Subject: Stormwater Runoff Calculations Date: 09/27/13 ENGINEERSBy: L. Warnick Page: E. FIND EXPECTED RUNOFF VOLUME (Vr) AND DESIGN VOLUME (Vd) Desicin Storm 100 -yr, 177 Using the Rational Method (Q = CIA) for the 100 -yr, 1 -hr storm which is the estimated time of concentration. Given: C Runoff Coefficient 0.95 See Appendix A.1 I Intensity 1 in/hr See Appendix A.2 A Drainage Area 0.27 acres See Page 5 Q Discharge = C*I*A 0.26 cfs I Storm Duration 1 hr Solution: Vr Runoff Volume= Q*t 923 cf Vd Allow for 15% Sedimentation = Vr*1.15 1,062 cf F. FIND SEEPAGE BED PROPERTIES Given: H Height 3.5 ft Seepage Bed #1 = 3.5' x 20' x 34' W Width 20 ft L Length 34 It Solution: Vb Bed (Rock) Volume = He*W*L 2,380 cf Vs Storage Volume = Vb*0.4 952 cf G. FIND VOLUME FROM INFILTRATION Given: As Area of bottom of infiltration window 680 sf r Infiltration Rate 2 in/hr Assumed I Duration 1 hr Solution: Vi Volume from Infiltration = As*(r/12)*t 113 cf H. CHECK AVAILABLE STORAGE > REQUIRED STORAGE (V) Given: Va Available Storage Volume (Vs + Vi) 1,065 cf Vd Required Volume 1,062 cf P:\2013\13031\Documents\Storm Calcs\RevA\3. Storm Calcs - 13021 Project: Parkview Christian Church Subject: Stormwater Runoff Calculations By: I Warnick Number: 13031A S P E N Date: 09/27/13 ENGINEERS Page: 8 6. RUNOFF CALCULATIONS FOR DRAINAGE AREA 2 A. FIND TIME OF CONCENTRATION (tc) Assume: The time of concentration (tc) for this area is defined as the time needed to reach the inlets from the point that is farthest away. It is assumed the time is 10 minutes. B. FIND PEAK DISCHARGE (Q) Design Storm 1 00- r, 10 -min Using the Rational Method (Q =CIA) for the 100 -yr, 10 -min storm which is the estimated time of concentration. Given: C Runoff Coefficient 0.80 1 Intensity 3.1 in/hr A Drainage Area 0.63 acres Solution: Q Peak Discharge = C*I*A 1.56 cfs C. FIND FLOW THROUGH DRAIN PIPE Given: Total Area D Pipe Diameter 12 in A Pipe flow area = pi * DA2/4 = 0.79 ft2 n Roughness coefficient = 0.009 R Hydraulic Radius = D/4 0.250 feet S Slope = 0.40% Solution: Q Flow =11.49 / n * A * RA2/3 * SAO .51 q Flow = 3.26 cfs [9RSIM Flow (q) > Peak Discharge (Q)? YES D. FIND VELOCITY IN GREASE TRAP (v) Given: Grease Trap Size 1,000 gal wt Trap Width 4.00 ft d Distance Between Baffles 15 in a Flow Area = wt*d 5.00 sf Solution: v Velocity = Q/a 0.31 fps Check: Velocity (v) < 0.5 fps? YES P:\2013\13031\Documents\Storm Calcs\RevA\3, Storm Calcs -13021 See Appendix A.1 See Appendix A.2 See Page 5 See Appendix C.1 Project: Parkview Christian Church Number: 13031 *0AS N Subject: Stormwater Runoff Calculations Date: 09/27/13ENGINFR.S By: L. Warnick Page: 9 E. FIND EXPECTED RUNOFF VOLUME (Vr) AND DESIGN VOLUME (Vd) Design Storm 100 -yr, 1 -hr Using the Rational Method (Q = CIA) for the 100 -yr, 1 -hr storm which is the estimated time of concentration. Given: C Runoff Coefficient 0.80 See Appendix A.1 I Intensity 1 in/hr See Appendix A.2 A Drainage Area 0.63 acres See Page 5 Q Discharge = C*I*A 0.50 cfs t Storm Duration 1 hr Solution: Vr Runoff Volume= Q*t 1,814 cf Vd Allow for 15% Sedimentation = Vr*1.15 2,087 cf F. FIND SEEPAGE BED PROPERTIES Given: H Height 3.5 It Seepage Bed #2 = 3.5'x 20'x 67' W Width 20 ft L Length 67 It Solution: Vb Bed (Rock) Volume = He*W*L 4,690 cf Vs Storage Volume = Vb*0.4 1,876 cf G. FIND VOLUME FROM INFILTRATION Given: As Area of bottom of infiltration window 1340 sf r Infiltration Rate 2 in/hr Assumed t Duration 1 hr Solution: Vi Volume from Infiltration = As*(r/12)*t 223 cf H. CHECK AVAILABLE STORAGE > REQUIRED STORAGE (V) Given: Va Available Storage Volume (Vs + Vi) 2,099 cf Vd Required Volume 2,087 cf P:\2013\13031\Documents\Storm Calcs\RevA\3. Storm Calcs - 13021 Project: Parkview Christian Church Subject: Stormwater Runoff Calculations By: L. Warnick Number: 09/27/13 9/27 A S P E N Date: os//0 ENGINEERS Page: /� 7. RUNOFF CALCULATIONS FOR DRAINAGE AREA 3 A. FIND TIME OF CONCENTRATION (tc) Assume: The time of concentration (tc) for this area is defined as the time needed to reach the inlets from the point that is farthest away. It is assumed the time is 10 minutes. B. FIND PEAK DISCHARGE (Q) Design Storm 100 -Yr, 10 -min Using the Rational Method (Q = CIA) for the 100 -yr, 10 -min storm which is the estimated time of concentration. Given: C Runoff Coefficient 0.80 I Intensity 3.1 in/hr A Drainage Area 0.98 acres Solution: Q Peak Discharge = C*1*A 2.43 cfs C. FIND FLOW THROUGH DRAIN PIPE Given: Total Area D Pipe Diameter 12 in A Pipe flow area = pi ` DA2/4 = 0.79 ft2 n Roughness coefficient = 0.009 R Hydraulic Radius = D/4 0.250 feet S Slope = 0.40% Solution: q Flow = [1.49 / n ` A' RA2/3 ' SAO .51 q Flow = 3.26 cfs Check: Flow (q) > Peak Discharge (Q)? YES D. FIND VELOCITY IN GREASE TRAP (v) Given: Grease Trap Size 1,000 gal wt Trap Width 4.00 ft d Distance Between Baffles 15 in a Flow Area = wt'd 5.00 sf Solution: v Velocity = Q/a 0.49 fps Check: Velocity (v) < 0.5 fps? YES P:\2013\13031\Documents\Storm Calcs\RevA\3. Storm Calcs - 13021 See Appendix A.1 See Appendix A.2 See Page 5 See Appendix C.1 Project: Parkview Christian Church Number: 13031A S P E N Subject: Stormwater Runoff Calculations Date: 09/27/13 ENGINEERS By: L. Warnick Page: /� E. FIND EXPECTED RUNOFF VOLUME (Vr) AND DESIGN VOLUME (Vd) Desi n Storm 1 00- r, 1 -hr Using the Rational Method (Q = CIA) for the 100 -yr, 1 -hr storm which is the estimated Solution: Vr Runoff Volume= Q*t 2,822 cf Vd Allow for 15% Sedimentation = W 1.15 3,246 cf F. FIND SEEPAGE BED PROPERTIES Given: H Height 3.5 It Seepage Bed #3 = 3.5'x 24'x 79' W Width 24 ft L Length 79 ft Solution: Vb Bed (Rock) Volume = He*W*L 6,636 cf Vs Storage Volume = Vb*0.4 2,654 cf G. FIND VOLUME FROM INFILTRATION Given: As Area of bottom of infiltration window 1896 sf r Infiltration Rate 4 in/hr Assumed t Duration 1 hr Solution: Vi Volume from Infiltration = As*(r/12)*t 632 cf H. CHECK AVAILABLE STORAGE > REQUIRED STORAGE (V) Given: Va Available Storage Volume (Vs + Vi) 3,286 cf Vd Required Volume 3,246 cf P:\2013\13031\Documents\Storm Calcs\RevA\3. Storm Calcs - 13021 time of concentration. Given: C Runoff Coefficient 0.80 See Appendix A.1 I Intensity 1 in/hr See Appendix A.2 A Drainage Area 0.98 acres See Page 5 Q Discharge = C*I*A 0.78 cfs t Storm Duration 1 hr Solution: Vr Runoff Volume= Q*t 2,822 cf Vd Allow for 15% Sedimentation = W 1.15 3,246 cf F. FIND SEEPAGE BED PROPERTIES Given: H Height 3.5 It Seepage Bed #3 = 3.5'x 24'x 79' W Width 24 ft L Length 79 ft Solution: Vb Bed (Rock) Volume = He*W*L 6,636 cf Vs Storage Volume = Vb*0.4 2,654 cf G. FIND VOLUME FROM INFILTRATION Given: As Area of bottom of infiltration window 1896 sf r Infiltration Rate 4 in/hr Assumed t Duration 1 hr Solution: Vi Volume from Infiltration = As*(r/12)*t 632 cf H. CHECK AVAILABLE STORAGE > REQUIRED STORAGE (V) Given: Va Available Storage Volume (Vs + Vi) 3,286 cf Vd Required Volume 3,246 cf P:\2013\13031\Documents\Storm Calcs\RevA\3. Storm Calcs - 13021 Project: Parkview Christian Church Subject: Stormwater Runoff Calculations By: I Warrick Number: A S P E N 09/27 Date: 09/27/13000 ENGINEERS Page: /7 8. RUNOFF CALCULATIONS FOR DRAINAGE AREA 4 A. FIND TIME OF CONCENTRATION (tc) Assume: The time of concentration (tc) for this area is defined as the time needed to reach the inlets from the point that is farthest away. It is assumed the time is 10 minutes. B. FIND PEAK DISCHARGE (Q) Design Storm 100 -Yr, 10 -min Using the Rational Method (Q = CIA) for the 100 -yr, 10 -min storm which is the estimated time of concentration. Given: C Runoff Coefficient I Intensity A Drainage Area Solution: Q Peak Discharge = C*I*A C. FIND FLOW THROUGH DRAIN PIPE Given: D Pipe Diameter A Pipe flow area = pi * DA2/4 = n Roughness coefficient = R Hydraulic Radius = D/4 S Slope = Solution: q Flow = [1.49 / n A * RA2/3 * SAO .5] q Flow = Check: Flow (q) > Peak Discharge (Q)? D. FIND VELOCITY IN GREASE TRAP (v) Given: Grease Trap Size wt Trap Width d Distance Between Baffles a Flow Area = wt*d Solution: v Velocity = Q/a Check: Velocity (v) < 0.5 fps? 0.95 3.1 in/hr 0.20 acres Total Area 12 in 0.79 ft' 0.009 0.250 feet 0.40% 3.26 cfs YES 1,000 gal 4.00 ft 15 in 5.00 sf 0.12 fps YES P:\2013\13031\Documents\Storm Calcs\RevA\3. Storm Calcs -13021 See Appendix A.1 See Appendix A.2 See Page 5 See Appendix CA Project: Parkview Christian Church Number: 13031 ASPEN Subject: Stormwater Runoff Calculations Date: 09/27/13 ENGINEERSBy: L. Warnick Page: /3 E. FIND EXPECTED RUNOFF VOLUME (Vr) AND DESIGN VOLUME (Vd) Desi n Storm 100- r, 1 -hr Using the Rational Method (Q =CIA) for the 100 -yr, 1 -hr storm which is the estimated Solution: Vr Runoff Volume= Q`t 684 cf Vd Allow for 15% Sedimentation = W1.1 5 787 cf F. FIND SEEPAGE BED PROPERTIES Given: H Height 3.5 ft Seepage Bed #4 = 3.5'x 15'x 31' W Width 15 ft L Length 31 ft Solution: Vb Bed (Rock) Volume = He'W'L 1,628 cf Vs Storage Volume = Vb'0.4 651 cf G. FIND VOLUME FROM INFILTRATION Given: As Area of bottom of infiltration window 465 sf r Infiltration Rate 4 in/hr Assumed t Duration 1 hr Solution: Vi Volume from Infiltration = As'(r/12)'t 155 cf H. CHECK AVAILABLE STORAGE > REQUIRED STORAGE (V) Given: Va Available Storage Volume (Vs + Vi) 806 cf Vd Required Volume 787 cf P:\2013\13031\Documents\Storm Calcs\RevA\3. Storm Calcs - 13021 time of concentration. Given: C Runoff Coefficient 0.95 See Appendix A.1 I Intensity 1 in/hr See Appendix A.2 A Drainage Area 0.20 acres See Page 5 Q Discharge = C'I'A 0.19 cfs t Storm Duration 1 hr Solution: Vr Runoff Volume= Q`t 684 cf Vd Allow for 15% Sedimentation = W1.1 5 787 cf F. FIND SEEPAGE BED PROPERTIES Given: H Height 3.5 ft Seepage Bed #4 = 3.5'x 15'x 31' W Width 15 ft L Length 31 ft Solution: Vb Bed (Rock) Volume = He'W'L 1,628 cf Vs Storage Volume = Vb'0.4 651 cf G. FIND VOLUME FROM INFILTRATION Given: As Area of bottom of infiltration window 465 sf r Infiltration Rate 4 in/hr Assumed t Duration 1 hr Solution: Vi Volume from Infiltration = As'(r/12)'t 155 cf H. CHECK AVAILABLE STORAGE > REQUIRED STORAGE (V) Given: Va Available Storage Volume (Vs + Vi) 806 cf Vd Required Volume 787 cf P:\2013\13031\Documents\Storm Calcs\RevA\3. Storm Calcs - 13021 Project: Parkview Christian Church Number: 13031 Subject: Stormwater Runoff Calculations Date: 09/27/13*O-ANSGn� n By: L. Warnick Page: Hydraulic Radius = D/4 0.250 feet 9. RUNOFF CALCULATIONS FOR DRAINAGE AREA 5 A. FIND TIME OF CONCENTRATION (tc) Assume: The time of concentration (tc) for this area is defined as the time needed to reach the inlets from the point that is farthest away. It is assumed the time is 10 minutes. B. FIND PEAK DISCHARGE (Q) Design Storm 100 -yr, 10 -min Using the Rational Method (Q = CIA) for the 100 -yr, 10 -min storm which is the estimated time of concentration. Given C Runoff Coefficient 0.95 1 Intensity 3.1 in/hr A Drainage Area 0.12 acres Solution: Q Peak Discharge = C*I*A 0.35 cfs C. FIND FLOW THROUGH DRAIN PIPE Given: Total Area D Pipe Diameter 12 in A Pipe flow area = pi * DA2 / 4 = 0.79 ft2 n Roughness coefficient = 0.009 R Hydraulic Radius = D/4 0.250 feet S Slope = 0.40% Solution: Flow = 11.49 / n * A * RA2/3 * SAO .51 q Flow = 3.26 cfs Check: Flow (q) > Peak Discharge (Q)? YES D. FIND VELOCITY IN GREASE TRAP (v) Given: Grease Trap Size 1,000 gal wt Trap Width 4.00 ft d Distance Between Baffles 15 in a Flow Area = wt*d 5.00 sf Solution: v Velocity = Q/a 0.07 fps Check: Velocity (v) < 0.5 fps? YES P:\2013\13031\Documents\Storm Calcs\RevA\3. Storm Calcs -13021 See Appendix A.1 See Appendix A.2 See Page 5 See Appendix C.1 Project: Parkview Christian Church Number: 13031A S P E N Subject: Stormwater Runoff Calculations Date: 09/27/13 ENGINEERS By: L. Warnick Page: i6 E. FIND EXPECTED RUNOFF VOLUME (Vr) AND DESIGN VOLUME (Vd) I Design Storm 100- r, 1 -hr Using the Rational Method (Q = CIA) for the 100 -yr, 1 -hr storm which is the estimated time of concentration. Given: C Runoff Coefficient 0.95 See Appendix A.1 I Intensity 1 in/hr See Appendix A.2 A Drainage Area 0.12 acres See Page 5 Q Discharge = C*I*A 0.11 cfs t Storm Duration 1 hr Solution: Vr Runoff Volume = Q*t 410 cf Vd Allow for 15% Sedimentation= Vr*1.15 472 cf F. FIND SEEPAGE BED PROPERTIES Given: H Height 3.5 ft Seepage Bed #5 = 3.5'x 20'x 14' W Width 20 ft L Length 14 ft Solution: Vb Bed (Rock) Volume = He*W*L 980 cf Vs Storage Volume= Vb*0.4 392 cf G. FIND VOLUME FROM INFILTRATION Given: As Area of bottom of infiltration window 280 sf r Infiltration Rate 4 in/hr Assumed t Duration 1 hr Solution: Vi Volume from Infiltration = As*(r/12)*t 93 cf H. CHECK AVAILABLE STORAGE > REQUIRED STORAGE (V) Given: Va Available Storage Volume (Vs + Vi) 485 cf Vd Required Volume 472 cf P:\2013\13031\Documents\Storm Calcs\RevA\3. Storm Calcs - 13021 Stormwater Management Calculations for Parkview Christian Church 201 W. Ustick Rd Meridian, Idaho APPENDIX A RUNOFF COEFFICIENTS AND RAINFALL INTENSITY P:\2013\13031\Documents\Storm Calcs\RevA\1. Storm Calculation Introduction.doc A.1 EXHIBIT "A" Recommended "C" Coefficients for "Rational Method Equation" Peak Rate of Discharge Description of Run -Off Area Runoff Coefficients "C' Business Downtown areas 0.95 Urban neighborhood areas 0.70 Residential Single-family 0.50 Multi -family 0.75 Residential (rural) 0.40 Apartment dwelling areas 0.70 Industrial and Commercial Light areas 0.80 Heavy areas 0.90 Parks, cemeteries 0.10 Playgrounds 0.20 Railroad yard areas 0.20 Unimproved areas 0.10 Streets Asphalt 0.95 Concrete 0.95 Brick 0.85 Drives and walks 0.85 Roofs 0.95 Fields: Sandy soil Flat 2% 0.05 Average 2-7% 0.10 Steep 7% 0.15 Fields: Clay soil Flat 2% 0.13 Average 2-7% 0.18 Steep 7% 0.25 Adapted from ASCE (1972 EXHIBIT "A" Adopted: Res. 469 (7/13/94) 8000-24 Revised: 7/19/95; 2/14/96; Res. 657 (8/28/02) 10.0 6.0 Ml 4.0 U W 2.0 CL = 1.0 U Z 0.6 ? 0.6 r 0.4 Z Z 0.2 J LL z 09 .06 44 A.2 Exhibit A 15 15 20 30 40 5060 2 3 4 5 6 8 1012 18 24 MINUTES DURATION HOURS �rrr�A ONE ���■1CURVMIME I■IIIii � '. � ■��w�■�wiwr�c ��w�sri\w► ■■rwrrC �r��w� �rrr►� NONNI "I'Mt§4h6464Q,j I �����I������I��■�� Wowm.�r.►.m, mob 15 15 20 30 40 5060 2 3 4 5 6 8 1012 18 24 MINUTES DURATION HOURS Stormwater Management Calculations for Parkview Christian Church 201 W. Ustick Rd Meridian. Idaho APPENDIX B INFILTRATION RATE INFORMATION P:\2013\13031\Documents\Storm Calcs\RevA\1. Storm Calculation Introduction.doc SA 112.3 Infiltration Rates Soil borings or test pits shall be taken at the basin sites to classify soil types. Infiltration rates shall be determined for design. A percolation test for the site specific soil conditions at the depth of the bed can be used. The table below presents typical infiltration rates. These values may be used based upon soil testing without an on-site percolation test. In no event will a rate exceeding 8 inches per hour be allowed. TABLE 3—ALLOWABLE INFILTRATION RATES SCS Group and Type Infiltration Rate (Inches/Hour) Infiltration without Pretreatment (inches/Hour) A. Sand 8 2 A. Loamy Sand 2 1 B. Sandy Loam 1 .5 B. Loam 0.5 .25 C. Silt Loam 0.25 ` 0 C. Sandy Clay Loam 0.15 0 D. Clay Loam & Silty Clay Loam <0.09 0 D. Clays <0.05 0 *Minimum rate, soils with lesser rates should not be considered as candidates for infiltration facilities. 112.4 Sediment and Grease Traps Properly sized standard sediment (sand) and grease traps shall be installed upstream of infiltration facilities. 112.5 Ground Water Elevations Groundwater elevation shall be established in accordance with Section 109.5. If groundwater is encountered during construction of the facility at an elevation higher than that shown on the plans, the facility shall be re -designed to account for the higher elevation. Water quality testing may be required by the City, Idaho Department of Water Resources, IDEQ or Southwest District Health Department. December 2005 16 of 20 Stonnwater Policy Stormwater Management Calculations for Parkview Christian Church 201 W. Ustick Rd Meridian, Idaho APPENDIX C SAND / GREASE TRAP CUT SHEETS P92013\13031\Documents\Storm Calcs\RevA\1. Storm Calculation Introduction.doc FLOW f7/19V1(a'11 O DESIGN L040 AA.SHTO HS -25 HIGHWAY LOADNG. (g) ALL REINFORCING STEEL SHALL BE GRADE 60. © DETAILED DRAWING OF A PRECAST BOX OR A POURED N PUCE BOX DESIGN MUST BE APPROVED BY THE ENGINEER PRIOR TO CONSTRUCTION. O BAFFLE WALL DETERMINED BY WALL CAPAND ACITY D INLET FLOW RATE of BEFORE THESE BOXES ARE USED THE APPLICATION MUST BE APPROVED BY THE ENGINEER © MA N14OLE FRAME. COLLAR AND COVER SHALL BE PER SD -616 AND SO -617. © IF DISTANCE FROM TOP OF BOX TO BOTTOM OF MAIIHOLE FORM EXCEEDS 12' USE PRECAST MANHOLE RISER PLUS A MAXIMUM OF 12' OF RISER GRADE RINGS. ON PROVIDE STEPS WHEN THE DISTANCE FROM TOP OF MANHOLE FRAME TO TOP OF BOX EXCEEDS 24'. 2005 LI -VI -11v FLOW O MANHOLE FRAME AND COVER PER SO -617 (TYPICAL) 2O LOCATION AND FLOW UNE ELEV. PER DESIGN PUNS. (TYPICAL) 5O CONCRETE RISER RINGS (MAX. 247 (TYPICAL). FOR VAULT DEPTH GREATER THAN 24'. USE PRECAST MANHOLE SECTIONS. STANDARD RING DEL. N > EL. D EL OUT < B UNLESS OTHERWISE APPROVED BY THE ENGINEER © WATERTIGHT SEAL CA I IDAHO STANDARDS I SAND AND GREASE I STANDARD DRAWING I FOR PUBLIC WORKS N0 CONSTRUCTION TRAP SD -624