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Home My WebLink AboutDrainage Report V1Kimley >>Horn Oakwind Estates Subdivision Meridian, ID Prepared By: Kimley-Horn Associates 950 W Bannock St Suite 1100 Boise, ID 83702 Contact: Brandon McDougald, P.E. (801) 915-7842 Job No. 093893000 February 04, 2022 Kimley»)Horn GENERAL LOCATION AND DESCRIPTION This drainage study is being prepared for both Phase 1 and Phase 2 of the Oakwind Estates Subdivision in Meridian, Idaho. The site is located to the northeast of the intersection of McDermott Road and McMillan Road. It is bound to the north by a commercial development, east by Phases 1 and 2 of the Oaks North Subdivision, west by McDermott Road, and south by McMillan Road. This project consists of approximately 24.36 acres and 185 lots. The site is located within section 28, Township 4 North, Range 1 West Meridian, Ada County, Idaho. The proposed development will consist of approximately 212 residential and common lots with the associated roadways and utilities. The site currently slopes mostly to the west at a grade of ±0.25-1%. The site is currently a portion of an undeveloped field used historically for agricultural purposes. The site is in zone "X", an area determined to be outside the 0.2% annual chance floodplain, according to the Flood Insurance Rate Map, Map Number 16001C0140J, which bears an effective date of June 19, 2020. II. HISTORIC DRAINAGE Currently, the site is undeveloped, and is bounded by McDermott Rd to the west and McMillan, to the south. This site generally slopes from the east to the west at a rate of approximately 0.25-1'%. In the existing condition it appears that storm water runoff will mostly infiltrate into the undeveloped ground. Any runoff appears to drain to ditches along McMillan or McDermott where it is eventually conveyed by a culvert under McDermott to the west. No detention/retention was found to be existing on the current site. III. DRAINAGE DESIGN CRITERIA Ada County Highway District (ACHD) requires that new developments provide primary conveyance for the 100-yr storm event and retention for the 100-yr storm event. The site has been designed to these standards with detention volumes being determined for the 1-hr 100-yr event per the ACHD Calculation Sheet for Finding Peak Discharge/Volume Spreadsheet. This volume was used to design the infiltration beds. The infiltration rate and high groundwater elevation for this design were taken from the geotechnical reports B180977g (July 20, 2018) and B210822g. (April 16, 2021) prepared by Materials Testing and Inspection, Inc. The Rational Method was used in calculating the required retention volume for the site. The site was delineated into drainage areas based upon the proposed grading and drainage design. The C-factor was taken to be 0.5 which is the higher end for single family residential listed in the ACHD "Estimated Runoff Coefficients for Various Surfaces" table. Along the McDermott Kimley»)Horn frontage where the residential C-factor did not apply, a composite C-factor was determined using 0.9 for the roadway and 0.35 for the planted areas. The required volume and the provided volume of retention for each drainage area has been calculated and is shown in the appendixes along with all design assumptions. III. PROPOSED DRAINAGE The proposed drainage infrastructure will consist of an on -site storm drain system discharging into an underground infiltration bed for each of the drainage areas. Prior to releasing water into the on -site underground infiltration beds, the water will be treated by a sand/oil separator unit per ISPWC SD-606. This treatment unit will be capable of treating the 25-year event. Since the seepage beds are located in common lots, no silt factor was used in sizing the infiltration beds per the requirements of the ACHD design requirements. The design infiltration rates were taken to be between 1-8in/hr per the geotechnical report No. 13180822g prepared by Materials Testing & Inspection, Inc prepared April 16th 2021. Each bed was assigned an infiltration rate in this 1-8in/hr range based upon its location on site in relation to the closest infiltration test. Given this infiltration rate each infiltration bed will drain in under the required 48 hrs. Kimley>»Horn 1y�_l:J:jAill 11:1 Seepage Bed - 1.1 Phase 1 ACHD Calculation Sheet for Sizing Seepage Bed With Optional Chambers NOTE: This worksheet is intended to be a guideline to standardize ACHD checking of drainage calculations and shall not replace the Engineer's calculation methodology. These calculations shall establish a minimum requirement. The Engineer's methodology must result in facilities that meet or exceed these calculations in order to be accepted. Note this spreadsheet pulls information from the "Peak QV" tab Calculate Post -Development Flows (for pre -development flows, increase number of storage facilities to create new tab) User input in yellow cells. 1 Project Name Oakwind Estates 2 Enter number of Seepage Beds (25 max) 3 Design Storm 4 Weighted Runoff Coefficient C 5 Area A (Acres) 6 Approved discharge rate (if applicable) 7 Is Seepage Bed in Common Lot? Yes 1Uu 0.50 1.17 acres 0.00 cfs V 2,022 8 Set Total Design Width of All Drain Rock W 9 Set Total Design Depth of All Drain Rock D Rock Only, Do Not Include Filter Sand Depth or Cover 10 Void Ratio of Drain Rock Voids 0.4 for 1.5"-2" drain rock and 3/4" Chips 11 Design Infiltration Rate (8 in/hr max) Perc 12 Size of WQ Perf Pipe (Pert 1800) Dia pipe 13 Size of Overflow Perf Pipe (Perfs 3600), READ if Q100>3.3 cfs 14 Calculate Total Storage per Foot 15 Calculate Design Length Override Value Required for Chambers 16 Variable Infiltration Window L 17 Variable Infiltration Window W 18 Time to Drain 90%volume in 48-hours minimum 19 Length of WQ & Overflow Perf Pipes 20 Perf Pipe Checks. Qperf >= Qpeak; where Qperf=CdxAxJ(2xgxH) 19.0 ft 3.0 ft 0.4 8.00 in/hr 18 in Spf 35.6 in 1 Link to: Qv QV TR55 2,022 ft3 0%Sediment 35.6 ft'/ft L 57 57 ft SWL 57 57.0 ft SWW 19.0 19.0 ft 2.5 hours 57 57 ft uptionai storage t nam Note: This assumes chambers are organized in a rectangular layout. 1 Type of Chambers 2 Volume to Store V 3 Installed Chamber Width Cw Installed Chamber Depth Cd Installed Chamber Height Ch 4 Chamber Void Factor 5 Chamber Storage Volume, Without Rock, Per Manuf 6 Chamber Storage Volume, With Rock, Per Manuf 7 Total Number of Units Required 8 Area of Infiltration 9 Volume Infiltration 10 Time to Drain 90%volume in 48-hours minimum Aperc ft 2 Vperc 0 ft3/hr hours ,3 K:\BOI_Civil\093893000 Oakwind BB Living\_Project Files\Eng\Drainage\ACHD Calcs\ACHD_SD_CALCS_SP01.1.xlsm 2/3/2022, 4:18 PM Version 10.0, May 2018 Seepage Bed - 1.2 Phase 1 ACHD Calculation Sheet for Sizing Seepage Bed With Optional Chambers NOTE: This worksheet is intended to be a guideline to standardize ACHD checking of drainage calculations and shall not replace the Engineer's calculation methodology. These calculations shall establish a minimum requirement. The Engineer's methodology must result in facilities that meet or exceed these calculations in order to be accepted. Note this spreadsheet pulls information from the "Peak QV" tab Calculate Post -Development Flows (for pre -development flows, increase number of storage facilities to create new tab) User input in yellow cells. 1 Project Name Oakwind Estates 2 Enter number of Seepage Beds (25 max) 3 Design Storm 4 Weighted Runoff Coefficient C 5 Area A (Acres) 6 Approved discharge rate (if applicable) 7 Is Seepage Bed in Common Lot? Yes 1Uu 0.50 1.75 acres 0.00 cfs V 3,024 8 Set Total Design Width of All Drain Rock W 9 Set Total Design Depth of All Drain Rock D Rock Only, Do Not Include Filter Sand Depth or Cover 10 Void Ratio of Drain Rock Voids 0.4 for 1.5"-2" drain rock and 3/4" Chips 11 Design Infiltration Rate (8 in/hr max) Perc 12 Size of WQ Perf Pipe (Pert 1800) Dia pipe 13 Size of Overflow Perf Pipe (Perfs 3600), READ if Q100>3.3 cfs 14 Calculate Total Storage per Foot 15 Calculate Design Length Override Value Required for Chambers 16 Variable Infiltration Window L 17 Variable Infiltration Window W 18 Time to Drain 90%volume in 48-hours minimum 19 Length of WQ & Overflow Perf Pipes 20 Perf Pipe Checks. Qperf >= Qpeak; where Qperf=CdxAxJ(2xgxH) 13.0 ft 3.0 ft 0.4 8.00 in/hr 18 in Spf 24.4 in 1 Link to: LQV QV TR55 3,024 ft' 0%Sediment 24.4 ft'/ft L 124 124 ft SWL 124 124.0 ft SWW 13.0 13.0 ft 2.5 hours 124 124 ft uptionai storage t nam Note: This assumes chambers are organized in a rectangular layout. 1 Type of Chambers 2 Volume to Store V 3 Installed Chamber Width Cw Installed Chamber Depth Cd Installed Chamber Height Ch 4 Chamber Void Factor 5 Chamber Storage Volume, Without Rock, Per Manuf 6 Chamber Storage Volume, With Rock, Per Manuf 7 Total Number of Units Required 8 Area of Infiltration 9 Volume Infiltration 10 Time to Drain 90%volume in 48-hours minimum Aperc ft2 Vperc 0 ft3/hr hours ft3 K:\BOI_Civil\093893000 Oakwind BB Living\_Project Files\Eng\Drainage\ACHD Calcs\ACHD_SD_CALCS_SP01.2.xlsm 2/3/2022, 4:19 PM Version 10.0, May 2018 Seepage Bed - 02 Phase 1 ACHD Calculation Sheet for Sizing Seepage Bed With Optional Chambers NOTE: This worksheet is intended to be a guideline to standardize ACHD checking of drainage calculations and shall not replace the Engineer's calculation methodology. These calculations shall establish a minimum requirement. The Engineer's methodology must result in facilities that meet or exceed these calculations in order to be accepted. Note this spreadsheet pulls information from the "Peak QV" tab Calculate Post -Development Flows (for pre -development flows, increase number of storage facilities to create new tab) User input in yellow cells. 1 Project Name Oakwind Estates 2 Enter number of Seepage Beds (25 max) 3 Design Storm 4 Weighted Runoff Coefficient C 5 Area A (Acres) 6 Approved discharge rate (if applicable) 7 Is Seepage Bed in Common Lot? Yes 1uu 0.50 5.99 acres 0.00 cfs V 10,351 8 Set Total Design Width of All Drain Rock W 9 Set Total Design Depth of All Drain Rock D Rock Only, Do Not Include Filter Sand Depth or Cover 10 Void Ratio of Drain Rock Voids 0.4 for 1.5"-2" drain rock and 3/4" Chips 11 Design Infiltration Rate (8 in/hr max) Perc 12 Size of WQ Perf Pipe (Pert 1800) Dia pipe 13 Size of Overflow Perf Pipe (Perfs 3600), READ if Q100>3.3 cfs 14 Calculate Total Storage per Foot 15 Calculate Design Length Override Value Required for Chambers 16 Variable Infiltration Window L 17 Variable Infiltration Window W 18 Time to Drain 90%volume in 48-hours minimum 19 Length of WQ & Overflow Perf Pipes 20 Perf Pipe Checks. Qperf >= Qpeak; where Qperf=CdxAxJ(2xgxH) 60.0 ft 3.0 ft 0.4 5.50 in/hr 18 in Spf 99.7 in 1 Link to: Qv QV TR55 10,351 ft' 0%Sediment 99.7 ft3/ft L 104 104 ft SWL 104 104.0 ft SWW 60.0 60.0 ft 3.3 hours 104 208 ft uptionai storage t nam Note: This assumes chambers are organized in a rectangular layout. 1 Type of Chambers 2 Volume to Store V 3 Installed Chamber Width Cw Installed Chamber Depth Cd Installed Chamber Height Ch 4 Chamber Void Factor 5 Chamber Storage Volume, Without Rock, Per Manuf 6 Chamber Storage Volume, With Rock, Per Manuf 7 Total Number of Units Required 8 Area of Infiltration 9 Volume Infiltration 10 Time to Drain 90%volume in 48-hours minimum Aperc ft 2 Vperc 0 ft3/hr hours ft3 K:\BOI_Civil\093893000 Oakwind BB Living\_Project Files\Eng\Drainage\ACHD Calcs\ACHD_SD_CALCS_SP02.xlsm 2/3/2022, 4:22 PM Version 10.0, May 2018 Seepage Bed - 03 Phase 1 ACHD Calculation Sheet for Sizing Seepage Bed With Optional Chambers NOTE: This worksheet is intended to be a guideline to standardize ACHD checking of drainage calculations and shall not replace the Engineer's calculation methodology. These calculations shall establish a minimum requirement. The Engineer's methodology must result in facilities that meet or exceed these calculations in order to be accepted. Note this spreadsheet pulls information from the "Peak QV" tab Calculate Post -Development Flows (for pre -development flows, increase number of storage facilities to create new tab) User input in yellow cells. 1 Project Name Oakwind Estates 2 Enter number of Seepage Beds (25 max) 3 Design Storm 4 Weighted Runoff Coefficient C 5 Area A (Acres) 6 Approved discharge rate (if applicable) 7 Is Seepage Bed in Common Lot? Yes luu 0.50 1.93 acres 0.00 cfs V 3,335 8 Set Total Design Width of All Drain Rock W 9 Set Total Design Depth of All Drain Rock D Rock Only, Do Not Include Filter Sand Depth or Cover 10 Void Ratio of Drain Rock Voids 0.4 for 1.5"-2" drain rock and 3/4" Chips 11 Design Infiltration Rate (8 in/hr max) Perc 12 Size of WQ Perf Pipe (Pert 1800) Dia pipe 13 Size of Overflow Perf Pipe (Perfs 3600), READ if Q100>3.3 cfs 14 Calculate Total Storage per Foot 15 Calculate Design Length Override Value Required for Chambers 16 Variable Infiltration Window L 17 Variable Infiltration Window W 18 Time to Drain 90%volume in 48-hours minimum 19 Length of WQ & Overflow Perf Pipes 20 Perf Pipe Checks. Qperf >= Qpeak; where Qperf=CdxAxJ(2xgxH) 17.0 ft 3.0 ft 0.4 1.00 in/hr 18 in Spf 22.0 in 1 Link to: LQV QV TR55 3,335 ft' 0%Sediment 22.0 ft3/ft L 152 152 ft SWL 152 152.0 ft SWW 17.0 17A ft 13.9 hours 152 100 ft uptionai storage t nam Note: This assumes chambers are organized in a rectangular layout. 1 Type of Chambers 2 Volume to Store V 3 Installed Chamber Width Cw Installed Chamber Depth Cd Installed Chamber Height Ch 4 Chamber Void Factor 5 Chamber Storage Volume, Without Rock, Per Manuf 6 Chamber Storage Volume, With Rock, Per Manuf 7 Total Number of Units Required 8 Area of Infiltration 9 Volume Infiltration 10 Time to Drain 90%volume in 48-hours minimum Aperc ft2 Vperc 0 ft3/hr hours ft3 K:\BOI_Civil\093893000 Oakwind BB Living\_Project Files\Eng\Drainage\ACHD Calcs\ACHD_SD_CALCS_SP03.xlsm 2/3/2022, 4:24 PM Version 10.0, May 2018 Seepage Bed - 04 Phase 1 ACHD Calculation Sheet for Sizing Seepage Bed With Optional Chambers NOTE: This worksheet is intended to be a guideline to standardize ACHD checking of drainage calculations and shall not replace the Engineer's calculation methodology. These calculations shall establish a minimum requirement. The Engineer's methodology must result in facilities that meet or exceed these calculations in order to be accepted. Note this spreadsheet pulls information from the "Peak QV" tab Calculate Post -Development Flows (for pre -development flows, increase number of storage facilities to create new tab) User input in yellow cells. 1 Project Name Oakwind Estates tnter number of Seepage beds (1S max) 3 Design Storm 100 4 Weighted Runoff Coefficient C 0.50 5 Area A (Acres) 2.19 acres 6 Approved discharge rate (if applicable) 0.00 cfs 7 Is Seepage Bed in Common Lot? Yes V 3,784 8 Set Total Design Width of All Drain Rock W 25.0 ft 9 Set Total Design Depth of All Drain Rock D 3.0 ft Rock Only, Do Not Include Filter Sand Depth or Cover 10 Void Ratio of Drain Rock Voids 0.4 0.4 for 1.5"-2" drain rock and 3/4" Chips 11 Design Infiltration Rate (8 in/hr max) Perc 6.50 in/hr 12 Size of WQ Perf Pipe (Pert 1800) Dia pipe 18 in 13 Size of Overflow Perf Pipe (Perfs 3600), READ if Q100>3.3 cfs in 14 Calculate Total Storage per Foot Link to: LQV QV TR55 3,784 ft3 0%Sediment Spf 43.7 43.7 ft3/ft 15 Calculate Design Length L 87 87 ft Override Value Required for Chambers 16 Variable Infiltration Window L SWL 87 87.0 ft 17 Variable Infiltration Window W SWW 25.0 25.0 ft 18 Time to Drain 2.9 hours 90%volume in 48-hours minimum 19 Length of WQ & Overflow Perf Pipes 87 87 ft 20 Perf Pipe Checks. Qperf >= Qpeak; where Qperf=CdxAxJ(2xgxH) Optional Storage Chambers Note: This assumes chambers are organized in a rectangular layout. 1-StormTech, 1 Type of Chambers SC740 2 Volume to Store V 0 ft3 3 Installed Chamber Width Cw 4.25 ft Installed Chamber Depth Cd 2.50 ft Installed Chamber Height Ch 7.12 ft 4 Chamber Void Factor 5 Chamber Storage Volume, Without Rock, Per Manuf 45.90 ft3/Unit 6 Chamber Storage Volume, With Rock, Per Manuf 74.90 ft3/Unit 7 Total Number of Units Required 0 ea 8 Area of Infiltration 9 Volume Infiltration 10 Time to Drain 90%volume in 48-hours minimum Aperc ftZ Vperc 0 ft3/hr hours K:\BOI_Civil\093893000 Oakwind BB Living\_Project Files\Eng\Drainage\ACHD Calcs\ACHD_SD_CALCS_SP04.xlsm 2/3/2022, 4:27 PM Version 10.0, May 2018 Seepage Bed - 05 Phase 1 ACHD Calculation Sheet for Sizing Seepage Bed With Optional Chambers NOTE: This worksheet is intended to be a guideline to standardize ACHD checking of drainage calculations and shall not replace the Engineer's calculation methodology. These calculations shall establish a minimum requirement. The Engineer's methodology must result in facilities that meet or exceed these calculations in order to be accepted. Note this spreadsheet pulls information from the "Peak QV" tab Calculate Post -Development Flows (for pre -development flows, increase number of storage facilities to create new tab) User input in yellow cells. 1 Project Name Oakwind Estates 2 Enter number of Seepage Beds (25 max) 3 Design Storm 4 Weighted Runoff Coefficient C 5 Area A (Acres) 6 Approved discharge rate (if applicable) 7 Is Seepage Bed in Common Lot? Yes 1Uu 0.50 0.93 acres 0.00 cfs V 1,607 8 Set Total Design Width of All Drain Rock W 9 Set Total Design Depth of All Drain Rock D Rock Only, Do Not Include Filter Sand Depth or Cover 10 Void Ratio of Drain Rock Voids 0.4 for 1.5"-2" drain rock and 3/4" Chips 11 Design Infiltration Rate (8 in/hr max) Perc 12 Size of WQ Perf Pipe (Pert 1800) Dia pipe 13 Size of Overflow Perf Pipe (Perfs 3600), READ if Q100>3.3 cfs 14 Calculate Total Storage per Foot 15 Calculate Design Length Override Value Required for Chambers 16 Variable Infiltration Window L 17 Variable Infiltration Window W 18 Time to Drain 90%volume in 48-hours minimum 19 Length of WQ & Overflow Perf Pipes 20 Perf Pipe Checks. Qperf >= Qpeak; where Qperf=CdxAxJ(2xgxH) 10.0 ft 3.0 ft 0.4 6.50 in/hr 18 in Spf 17.6 in 1 Link to: Qv QV TR55 1,607 ft' 0%Sediment 17.6 ft3/ft L 91 92 ft SWL 92 92.0 ft SWW 10.0 10.0 ft 2.9 hours 92 92 ft uptionai storage t nam Note: This assumes chambers are organized in a rectangular layout. 1 Type of Chambers 2 Volume to Store V 3 Installed Chamber Width Cw Installed Chamber Depth Cd Installed Chamber Height Ch 4 Chamber Void Factor 5 Chamber Storage Volume, Without Rock, Per Manuf 6 Chamber Storage Volume, With Rock, Per Manuf 7 Total Number of Units Required 8 Area of Infiltration 9 Volume Infiltration 10 Time to Drain 90%volume in 48-hours minimum Aperc ft 2 Vperc 0 ft3/hr hours ft3 K:\BO1_Civil\093893000 Oakwind BB Living\_Project Files\Eng\Drainage\ACHD Calcs\ACHD_SD_CALCS_SPOS.xlsm 2/3/2022, 4:29 PM Version 10.0, May 2018 Seepage Bed - 06 Phase 1 ACHD Calculation Sheet for Sizing Seepage Bed With Optional Chambers NOTE: This worksheet is intended to be a guideline to standardize ACHD checking of drainage calculations and shall not replace the Engineer's calculation methodology. These calculations shall establish a minimum requirement. The Engineer's methodology must result in facilities that meet or exceed these calculations in order to be accepted. Note this spreadsheet pulls information from the "Peak QV" tab Calculate Post -Development Flows (for pre -development flows, increase number of storage facilities to create new tab) User input in yellow cells. 1 Project Name Oakwind Estates 2 Enter number of Seepage Beds (25 max) 3 Design Storm 4 Weighted Runoff Coefficient C 5 Area A (Acres) 6 Approved discharge rate (if applicable) 7 Is Seepage Bed in Common Lot? Yes 1Uu 0.50 1.51 acres 0.00 cfs V 2,609 8 Set Total Design Width of All Drain Rock W 9 Set Total Design Depth of All Drain Rock D Rock Only, Do Not Include Filter Sand Depth or Cover 10 Void Ratio of Drain Rock Voids 0.4 for 1.5"-2" drain rock and 3/4" Chips 11 Design Infiltration Rate (8 in/hr max) Perc 12 Size of WQ Perf Pipe (Pert 1800) Dia pipe 13 Size of Overflow Perf Pipe (Perfs 3600), READ if Q100>3.3 cfs 14 Calculate Total Storage per Foot 15 Calculate Design Length Override Value Required for Chambers 16 Variable Infiltration Window L 17 Variable Infiltration Window W 18 Time to Drain 90%volume in 48-hours minimum 19 Length of WQ & Overflow Perf Pipes 20 Perf Pipe Checks. Qperf >= Qpeak; where Qperf=CdxAxJ(2xgxH) 20.0 ft 3.0 ft 0.4 7.50 in/hr 18 in Spf 36.7 in 3 Link to: Qv QV TR55 2,609 ft3 0%Sediment 36.7 ft3/ft L 71 72 ft SWL 72 72.0 ft SWW 20.0 20.0 ft 2.6 hours 72 72 ft uptionai storage t nam Note: This assumes chambers are organized in a rectangular layout. 1 Type of Chambers 2 Volume to Store V 3 Installed Chamber Width Cw Installed Chamber Depth Cd Installed Chamber Height Ch 4 Chamber Void Factor 5 Chamber Storage Volume, Without Rock, Per Manuf 6 Chamber Storage Volume, With Rock, Per Manuf 7 Total Number of Units Required 8 Area of Infiltration 9 Volume Infiltration 10 Time to Drain 90%volume in 48-hours minimum Aperc ft 2 Vperc 0 ft3/hr hours ft3 K:\BOI_Civil\093893000 Oakwind BB Living\_Project Files\Eng\Drainage\ACHD Calcs\ACHD_SD_CALCS_SP06.xlsm 2/3/2022, 4:30 PM Version 10.0, May 2018 Seepage Bed - 07 Phase 1 ACHD Calculation Sheet for Sizing Seepage Bed With Optional Chambers NOTE: This worksheet is intended to be a guideline to standardize ACHD checking of drainage calculations and shall not replace the Engineer's calculation methodology. These calculations shall establish a minimum requirement. The Engineer's methodology must result in facilities that meet or exceed these calculations in order to be accepted. Note this spreadsheet pulls information from the "Peak QV" tab Calculate Post -Development Flows (for pre -development flows, increase number of storage facilities to create new tab) User input in yellow cells. 1 Project Name Oakwind Estates 2 Enter number of Seepage Beds (25 max) 3 Design Storm 4 Weighted Runoff Coefficient C 5 Area A (Acres) 6 Approved discharge rate (if applicable) 7 Is Seepage Bed in Common Lot? Yes 1Uu 0.65 0.63 acres 0.00 cfs V 1,415 8 Set Total Design Width of All Drain Rock W 9 Set Total Design Depth of All Drain Rock D Rock Only, Do Not Include Filter Sand Depth or Cover 10 Void Ratio of Drain Rock Voids 0.4 for 1.5"-2" drain rock and 3/4" Chips 11 Design Infiltration Rate (8 in/hr max) Perc 12 Size of WQ Perf Pipe (Pert 1800) Dia pipe 13 Size of Overflow Perf Pipe (Perfs 3600), READ if Q100>3.3 cfs 14 Calculate Total Storage per Foot 15 Calculate Design Length Override Value Required for Chambers 16 Variable Infiltration Window L 17 Variable Infiltration Window W 18 Time to Drain 90%volume in 48-hours minimum 19 Length of WQ & Overflow Perf Pipes 20 Perf Pipe Checks. Qperf >= Qpeak; where Qperf=CdxAxJ(2xgxH) 10.0 ft 3.0 ft 0.4 1.00 in/hr 18 in Spf 13.0 in 1 Link to: Qv QV TR55 1,415 ft3 0%Sediment 13.0 ft3/ft L 109 109 ft SWL 109 109.0 ft SWW 10.0 10.0 ft 14.0 hours 109 109 ft uptionai storage t nam Note: This assumes chambers are organized in a rectangular layout. 1 Type of Chambers 2 Volume to Store V 3 Installed Chamber Width Cw Installed Chamber Depth Cd Installed Chamber Height Ch 4 Chamber Void Factor 5 Chamber Storage Volume, Without Rock, Per Manuf 6 Chamber Storage Volume, With Rock, Per Manuf 7 Total Number of Units Required 8 Area of Infiltration 9 Volume Infiltration 10 Time to Drain 90%volume in 48-hours minimum Aperc ft 2 Vperc 0 ft3/hr hours ft3 K:\BOI_Civil\093893000 Oakwind BB Living\_Project Files\Eng\Drainage\ACHD Calcs\ACHD_SD_CALCS_SP07.xlsm 2/3/2022, 4:32 PM Version 10.0, May 2018 Seepage Bed - 08 Phase 1 ACHD Calculation Sheet for Sizing Seepage Bed With Optional Chambers NOTE: This worksheet is intended to be a guideline to standardize ACHD checking of drainage calculations and shall not replace the Engineer's calculation methodology. These calculations shall establish a minimum requirement. The Engineer's methodology must result in facilities that meet or exceed these calculations in order to be accepted. Note this spreadsheet pulls information from the "Peak QV" tab Calculate Post -Development Flows (for pre -development flows, increase number of storage facilities to create new tab) User input in yellow cells. 1 Project Name Oakwind Estates 2 Enter number of Seepage Beds (25 max) 3 Design Storm 4 Weighted Runoff Coefficient C 5 Area A (Acres) 6 Approved discharge rate (if applicable) 7 Is Seepage Bed in Common Lot? Yes 1Uu 0.65 0.26 acres 0.00 cfs V 584 8 Set Total Design Width of All Drain Rock W 9 Set Total Design Depth of All Drain Rock D Rock Only, Do Not Include Filter Sand Depth or Cover 10 Void Ratio of Drain Rock Voids 0.4 for 1.5"-2" drain rock and 3/4" Chips 11 Design Infiltration Rate (8 in/hr max) Perc 12 Size of WQ Perf Pipe (Pert 1800) Dia pipe 13 Size of Overflow Perf Pipe (Perfs 3600), READ if Q100>3.3 cfs 14 Calculate Total Storage per Foot 15 Calculate Design Length Override Value Required for Chambers 16 Variable Infiltration Window L 17 Variable Infiltration Window W 18 Time to Drain 90%volume in 48-hours minimum 19 Length of WQ & Overflow Perf Pipes 20 Perf Pipe Checks. Qperf >= Qpeak; where Qperf=CdxAxJ(2xgxH) 10.0 ft 3.0 ft 0.4 8.00 in/hr 18 in Spf 18.8 in 1 Link to: Qv QV TR55 584 ft' 0%Sediment 18.8 ft3/ft L 31 32 ft SWL 32 32.0 ft SWW 10.0 10.0 ft 2.5 hours 32 32 ft uptionai storage t nam Note: This assumes chambers are organized in a rectangular layout. 1 Type of Chambers 2 Volume to Store V 3 Installed Chamber Width Cw Installed Chamber Depth Cd Installed Chamber Height Ch 4 Chamber Void Factor 5 Chamber Storage Volume, Without Rock, Per Manuf 6 Chamber Storage Volume, With Rock, Per Manuf 7 Total Number of Units Required 8 Area of Infiltration 9 Volume Infiltration 10 Time to Drain 90%volume in 48-hours minimum Aperc ft 2 Vperc 0 ft3/hr hours ft3 K:\BOI_Civil\093893000 Oakwind BB Living\_Project Files\Eng\Drainage\ACHD Calcs\ACHD_SD_CALCS_SP08.xlsm 2/3/2022, 4:33 PM Version 10.0, May 2018 Seepage Bed - 09 Phase 1 ACHD Calculation Sheet for Sizing Seepage Bed With Optional Chambers NOTE: This worksheet is intended to be a guideline to standardize ACHD checking of drainage calculations and shall not replace the Engineer's calculation methodology. These calculations shall establish a minimum requirement. The Engineer's methodology must result in facilities that meet or exceed these calculations in order to be accepted. Note this spreadsheet pulls information from the "Peak QV" tab Calculate Post -Development Flows (for pre -development flows, increase number of storage facilities to create new tab) User input in yellow cells. 1 Project Name Oakwind Estates 2 Enter number of Seepage Beds (25 max) 3 Design Storm 4 Weighted Runoff Coefficient C 5 Area A (Acres) 6 Approved discharge rate (if applicable) 7 Is Seepage Bed in Common Lot? Yes 1Uu 0.65 0.84 acres 0.00 cfs V 1,887 8 Set Total Design Width of All Drain Rock W 9 Set Total Design Depth of All Drain Rock D Rock Only, Do Not Include Filter Sand Depth or Cover 10 Void Ratio of Drain Rock Voids 0.4 for 1.5"-2" drain rock and 3/4" Chips 11 Design Infiltration Rate (8 in/hr max) Perc 12 Size of WQ Perf Pipe (Pert 1800) Dia pipe 13 Size of Overflow Perf Pipe (Perfs 3600), READ if Q100>3.3 cfs 14 Calculate Total Storage per Foot 15 Calculate Design Length Override Value Required for Chambers 16 Variable Infiltration Window L 17 Variable Infiltration Window W 18 Time to Drain 90%volume in 48-hours minimum 19 Length of WQ & Overflow Perf Pipes 20 Perf Pipe Checks. Qperf >= Qpeak; where Qperf=CdxAxJ(2xgxH) 10.0 ft 3.0 ft 0.4 3.00 in/hr 18 in Spf 14.7 in 1 Link to: Qv QV TR55 1,887 ft3 0%Sediment 14.7 ft3/ft L 128 129 ft SWL 129 101.0 ft SWW 10.0 10.0 ft 6.7 hours 129 101 ft Optional Storage Charm Note: This assumes chambers are organized in a rectangular layout. 1 Type of Chambers 2 Volume to Store V 3 Installed Chamber Width Cw Installed Chamber Depth Cd Installed Chamber Height Ch 4 Chamber Void Factor 5 Chamber Storage Volume, Without Rock, Per Manuf 6 Chamber Storage Volume, With Rock, Per Manuf 7 Total Number of Units Required 8 Area of Infiltration 9 Volume Infiltration 10 Time to Drain 90%volume in 48-hours minimum Aperc ft 2 Vperc 0 ft3/hr hours ft3 K:\BOI_Civil\093893000 Oakwind BB Living\_Project Files\Eng\Drainage\ACHD Calcs\ACHD_SD_CALCS_SP09.xlsm 2/3/2022, 4:35 PM Version 10.0, May 2018 Seepage Bed - 1 Phase 2 ACHD Calculation Sheet for Sizing Seepage Bed With Optional Chambers NOTE: This worksheet is intended to be a guideline to standardize ACHD checking of drainage calculations and shall not replace the Engineer's calculation methodology. These calculations shall establish a minimum requirement. The Engineer's methodology must result in facilities that meet or exceed these calculations in order to be accepted. Note this spreadsheet pulls information from the "Peak QV" tab Calculate Post -Development Flows (for pre -development flows, increase number of storage facilities to create new tab) User input in yellow cells. 1 Project Name Oakwind Estates tnter number of Seepage beds (1S max) 3 Design Storm 100 4 Weighted Runoff Coefficient C 0.50 5 Area A (Acres) 2.02 acres 6 Approved discharge rate (if applicable) 0.00 cfs 7 Is Seepage Bed in Common Lot? Yes V 3,491 8 Set Total Design Width of All Drain Rock W 39.0 ft 9 Set Total Design Depth of All Drain Rock D 3.0 ft Rock Only, Do Not Include Filter Sand Depth or Cover 10 Void Ratio of Drain Rock Voids 0.4 0.4 for 1.5"-2" drain rock and 3/4" Chips 11 Design Infiltration Rate (8 in/hr max) Perc 3.00 in/hr 12 Size of WQ Perf Pipe (Pert 1800) Dia pipe 18 in 13 Size of Overflow Perf Pipe (Perfs 3600), READ if Q100>3.3 cfs in 14 Calculate Total Storage per Foot Link to: LQV QV TR55 3,491 ft3 0%Sediment Spf 56.7 56.7 ft3/ft 15 Calculate Design Length L 62 62 ft Override Value Required for Chambers 16 Variable Infiltration Window L SWL 62 62.0 ft 17 Variable Infiltration Window W SWW 39.0 39.0 ft 18 Time to Drain 5.2 hours 90%volume in 48-hours minimum 19 Length of WQ & Overflow Perf Pipes 62 62 ft 20 Perf Pipe Checks. Qperf >= Qpeak; where Qperf=CdxAxJ(2xgxH) Optional Storage Chambers - Note: This assumes chambers are organized in a rectangular layout. 1-StormTech, 1 Type of Chambers SC740 2 Volume to Store V 0 ft3 3 Installed Chamber Width Cw 4.25 ft Installed Chamber Depth Cd 2.50 ft Installed Chamber Height Ch 7.12 ft 4 Chamber Void Factor 5 Chamber Storage Volume, Without Rock, Per Manuf 45.90 ft3/Unit 6 Chamber Storage Volume, With Rock, Per Manuf 74.90 ft3/Unit 7 Total Number of Units Required 0 ea 8 Area of Infiltration 9 Volume Infiltration 10 Time to Drain 90%volume in 48-hours minimum Aperc ftZ Vperc 0 ft3/hr hours K:\BOI_Civil\093893000 Oakwind BB Living\_Project Files\Eng\Drainage\ACHD Calcs\ACHD_SD_CALCS_PH2_SP1.xlsm 2/3/2022, 4:37 PM Version 10.0, May 2018 Seepage Bed - 2 Phase 2 ACHD Calculation Sheet for Sizing Seepage Bed With Optional Chambers NOTE: This worksheet is intended to be a guideline to standardize ACHD checking of drainage calculations and shall not replace the Engineer's calculation methodology. These calculations shall establish a minimum requirement. The Engineer's methodology must result in facilities that meet or exceed these calculations in order to be accepted. Note this spreadsheet pulls information from the "Peak QV" tab Calculate Post -Development Flows (for pre -development flows, increase number of storage facilities to create new tab) User input in yellow cells. 1 Project Name Oakwind Estates 2 Enter number of Seepage Beds (25 max) 3 Design Storm 4 Weighted Runoff Coefficient C 5 Area A (Acres) 6 Approved discharge rate (if applicable) 7 Is Seepage Bed in Common Lot? Yes 1Uu 0.50 1.75 acres 0.00 cfs V 3,024 8 Set Total Design Width of All Drain Rock W 9 Set Total Design Depth of All Drain Rock D Rock Only, Do Not Include Filter Sand Depth or Cover 10 Void Ratio of Drain Rock Voids 0.4 for 1.5"-2" drain rock and 3/4" Chips 11 Design Infiltration Rate (8 in/hr max) Perc 12 Size of WQ Perf Pipe (Pert 1800) Dia pipe 13 Size of Overflow Perf Pipe (Perfs 3600), READ if Q100>3.3 cfs 14 Calculate Total Storage per Foot 15 Calculate Design Length Override Value Required for Chambers 16 Variable Infiltration Window L 17 Variable Infiltration Window W 18 Time to Drain 90%volume in 48-hours minimum 19 Length of WQ & Overflow Perf Pipes 20 Perf Pipe Checks. Qperf >= Qpeak; where Qperf=CdxAxJ(2xgxH) 17.0 ft 3.0 ft 0.4 3.30 in/hr 18 in Spf 25.3 in 1 Link to: Qv QV TR55 3,024 ft3 0%Sediment 25.3 ft3/ft L 120 120 ft SWL 120 120.0 ft SWW 17.0 17.0 ft 4.9 hours 120 120 ft Optional Storage Charm Note: This assumes chambers are organized in a rectangular layout. 1 Type of Chambers 2 Volume to Store V 3 Installed Chamber Width Cw Installed Chamber Depth Cd Installed Chamber Height Ch 4 Chamber Void Factor 5 Chamber Storage Volume, Without Rock, Per Manuf 6 Chamber Storage Volume, With Rock, Per Manuf 7 Total Number of Units Required 8 Area of Infiltration 9 Volume Infiltration 10 Time to Drain 90%volume in 48-hours minimum Aperc ft 2 Vperc 0 ft3/hr hours ft3 K:\BOI_Civil\093893000 Oakwind BB Living\_Project Files\Eng\Drainage\ACHD Calcs\ACHD_SD_CALCS_PH2_SP2.xlsm 2/3/2022, 4:39 PM Version 10.0, May 2018 Seepage Bed - 3 Phase 2 ACHD Calculation Sheet for Sizing Seepage Bed With Optional Chambers NOTE: This worksheet is intended to be a guideline to standardize ACHD checking of drainage calculations and shall not replace the Engineer's calculation methodology. These calculations shall establish a minimum requirement. The Engineer's methodology must result in facilities that meet or exceed these calculations in order to be accepted. Note this spreadsheet pulls information from the "Peak QV" tab Calculate Post -Development Flows (for pre -development flows, increase number of storage facilities to create new tab) User input in yellow cells. 1 Project Name Oakwind Estates z tnter number of Seepage beds (1S max) 3 Design Storm 100 4 Weighted Runoff Coefficient C 0.50 5 Area A (Acres) 2.69 acres 6 Approved discharge rate (if applicable) 0.00 cfs 7 Is Seepage Bed in Common Lot? Yes V 4,648 8 Set Total Design Width of All Drain Rock W 22.0 ft 9 Set Total Design Depth of All Drain Rock D 3.0 ft Rock Only, Do Not Include Filter Sand Depth or Cover 10 Void Ratio of Drain Rock Voids 0.4 0.4 for 1.5"-2" drain rock and 3/4" Chips 11 Design Infiltration Rate (8 in/hr max) Perc 3.40 in/hr 12 Size of WQ Perf Pipe (Pert 1800) Dia pipe 18 in 13 Size of Overflow Perf Pipe (Perfs 3600), READ if Q100>3.3 cfs in 14 Calculate Total Storage per Foot Link to: LQV QV TR55 4,648 ft3 0%Sediment Spf 32.8 32.8 ft3/ft 15 Calculate Design Length L 142 142 ft Override Value Required for Chambers 16 Variable Infiltration Window L SWL 142 142.0 ft 17 Variable Infiltration Window W SWW 22.0 22.0 ft 18 Time to Drain 4.7 hours 90%volume in 48-hours minimum 19 Length of WQ & Overflow Perf Pipes 142 142 ft 20 Perf Pipe Checks. Qperf >= Qpeak; where Qperf=CdxAxJ(2xgxH) Optional Storage Chambers Note: This assumes chambers are organized in a rectangular layout. 1-StormTech, 1 Type of Chambers SC740 2 Volume to Store V 0 ft3 3 Installed Chamber Width Cw 4.25 ft Installed Chamber Depth Cd 2.50 ft Installed Chamber Height Ch 7.12 ft 4 Chamber Void Factor 5 Chamber Storage Volume, Without Rock, Per Manuf 45.90 ft3/Unit 6 Chamber Storage Volume, With Rock, Per Manuf 74.90 ft3/Unit 7 Total Number of Units Required 0 ea 8 Area of Infiltration 9 Volume Infiltration 10 Time to Drain 90%volume in 48-hours minimum Aperc ftZ Vperc 0 ft3/hr hours K:\BOI_Civil\093893000 Oakwind BB Living\_Project Files\Eng\Drainage\ACHD Calcs\ACHD_SD_CALCS_PH2_SP3.xlsm 2/3/2022, 4:40 PM Version 10.0, May 2018 APN: SO429440000 APN: SO428325610 APN"— J SO428325460 r----------------------------------- ---------------------------------------------r--- ---- PHASE 2 1 — — — — — — SP-3a BLOCK 8 1 1 I 3 I 2 1 1 i I 51 I I I 1 11 11 5 I 4 I I 1 r---- I I 15 I 14 1 13 12 1 11 I 10 I 9 I 8 0.5 � I I 16 9 BLOCK 8 PHASE 2 — — 2.69 SP 1 _1 IIII r— I _ _W AVILLA ST _ e� — -- — 1 PHASE 2II� Q= 0.65 CB3 & 4 EXISTING OAKS NORTH 12 W 19 14 15 16 17 PHASE 2 1 18 20 21 — 2 SUBDIVISION NO. 2 0. — 84 O PHASE 2 SP 3b „', CB1 & 2_ BLOCK 7 I I I I 1, 1 — — (NOT A PART) 00 2 20 III III 1111... 1 1� Uu I Q 3 > 0.5 11 10 9 8 6 0.5 4 3 �� ,, z — — �O — — s 1 21 III 2.02 PHASE 2 L 1.75 BLOCK 7 � Q sP—os _ _ _ _ c67 & s _ _ — — 4 I� W SOPRANO ST � � � 22 — — W \ 23 I III � III J' 15 16 17 18 19 20 21 22 23 1 6 / PHASE 2 D III III I I sP-2 BLOCK 6 • 24 II BLOCK 6 i 1 'i1 / 7 III 13 1 11 10 g 0.5 6 5 4 3 2 1 5 26.2 2.42 )Ili IIII / II 26 I — — W MILANO ST — PHASE 2 00 27 r � I CBS & 6 — — O SP 02 5 7 9 1 10 1 Co 28 III I II II Q BLOCK 4 Q — — 4 29 5 2 I III I / Q I II II 3 I II � III — 4J = I 9 I II z I 7 BLOCK 4 � 12 0.65 30 I / Z 0.26 BLOC 5 BLOCK 4 Z °r° 1 I I 2 0.5 O I SP-08 Ili it 10 III 6 6.1 13 n 1 I 3.57 4 I / \ I 0.5 BL 5 _ W DAPHNE ST 14 1.17 I� 111IJ — SP-1.2 CB03 & 04 — — — — — — SP-1.1 W DAPHNE ST —49 _ — 1 3.2 BLOCK 3 — F — — I IIII . r481 1 7156 o.5 I II I 1 I — 1 117 14 13 12 11 10 9 5 4 I I 3 2�� — —1 0.5 47 I I CB01 & 02 — SP-06I — — 5 0.93 —03 03 III 1 46 It0 /4 45 _ CB11 cn II 1 +J Q I I I I I I I I I I I BLOCK 2 1 I I r 5 �� EXISTING OAKS NORTH _ 16 15 14 13 1 11 10 9 8 7 6 1 4 2 1 I SUBDIVISION NO. 1 44 I I I I I I I I I I I I I I 3 1I (NOT A PART) 1 J Z SP-05 10 z \, � 10 43 17 0.63 — �— I r 42— CB09 & 10 SP-04 1 I I I I I I I I I I I I 1 1 I I 1118 1 19 1 20 1 21 1 22 1 231 1 124 1 5 1 26 1 27 1 28 1 2911 1 1131 i 32 33 i 34 i 3 41 1 1 I -- 1— _ I ' \ 511 40— J9 � TL_L_ )_ �LLe I J 10 — — 1 SP-07 W RIVA CAPRI ST \ 1 38 015 CB05 & 06 0 5 W Z / 38 11 / 1.93 e — — _ — 2.19 — Ip SP-03 C607 & 08 I I _ � I 1 — 37 I I BLOCK 1 1 — J 11 34 33 32 i 31 i 3d 1 29 28 1 27 i 26 25 i 241 i 123 1 22 1 21 1 20 1 19 1 181 1 117 116 15 114 113 1 12 _. ---1 1 I I I 1 I I I 52— I' I — — �52 -------_ __ _ — — — --- — � —=F _.. - - - _.- --- L f.,_ - __.... _ .._._ C -- - -,��rrrrrr��w� - - - -- — - — — W RIVA CAPRI ST EXISTING OAKS WEST SUBDIVISION NO. 1 (NOT A PART) — — — LEGEND C FACTOR o.5 DRAINAGE AREA DESIGNATION 7 DRAINAGE AREA (AC) ### DRAINAGE AREA BOUNDARY PHASE BOUNDARY GRAPHIC SCALE IN FEET 0 30 60 120 NORTH OAKWIND ESTATES PROPOSED DRAINAGE AREA M MERIDIAN, ID Call before yo„ dig. CALL 2 BUSINESS DAYS IN ADVANCE BEFORE YOU DIG, GRADE, OR EXCAVATE FOR THE MARKING OF UNDERGROUND MEMBER UTILITIES Kimley)))Horn 02022 KIMLEY—HORN AND ASSOCIATES, INC. 950 Bannock Street, Suite 1100 FOR REVIEW ONLY NOT FOR CONSTRUCTION Kimley)Morn SCALE (H): 1••=60• 6 SCALE (V): N/A w 1 1 National Flood Hazard Layer FIRMette .. FEMA 116o28'38"W 43o39'13"N -- 1.17,VVV 0 250 500 1,000 1,500 2,000 Basemap: USGS National Map: Orthoimagery. Data refreshed October, 2020 Legend SEE FIS REPORT FOR DETAILED LEGEND AND INDEX MAP FOR FIRM PANEL LAYOUT Without Base Flood Elevation (BFE) Zone A, V, A99 SPECIAL FLOOD With BFE or Depth Zone AE, Ao, AH. VE. AR HAZARD AREAS Regulatory Floodway 0.2% Annual Chance Flood Hazard, Areas of 1% annual chance flood with average depth less than one foot or with drainage areas of less than one square mile Zonex Future " Conditions 1% Annual Chance Flood Hazard Zone Area with Reduced Flood Risk due to OTHER AREAS OF Levee. See Notes. Zone FLOOD HAZARD Area with Flood Risk due to Levee zone D NO SCREEN Area of Minimal Flood Hazard Zone Q Effective LOMRs OTHER AREAS Area of Undetermined Flood Hazard Zone D GENERAL - — - - Channel, Culvert, or Storm Sewer STRUCTURES I I I I I I I Levee, Dike, or Floodwall Cross Sections with 1% Annual Chance 17•5 Water Surface Elevation a - - - Coastal Transact —5f5— Base Flood Elevation Line (BFE) Limit of Study Jurisdiction Boundary — --- Coastal Transact Baseline OTHER _ Profile Baseline FEATURES Hydrographic Feature Digital Data Available N No Digital Data Available MAP PANELS Unmapped QThe pin displayed on the map is an approximate point selected by the user and does not represent an authoritative property location. This map complies with FEMA's standards for the use of digital flood maps if it is not void as described below. The basemap shown complies with FEMA's basemap accuracy standards The flood hazard information is derived directly from the authoritative NFHL web services provided by FEMA. This map was exported on 1/11/2022 at 10:34 AM and does not reflect changes or amendments subsequent to this date and time. The NFHL and effective information may change or become superseded by new data over time. This map image is void if the one or more of the following map elements do not appear: basemap imagery, flood zone labels, legend, scale bar, map creation date, community identifiers, FIRM panel number, and FIRM effective date. Map images for unmapped and unmodernized areas cannot be used for regulatory purposes.