City of Thornton Attn: Tim Semones Development Engineeering 9500 Civic Center Dr. Thornton, CO 80229

Transcription

1 Development Engineering Land Surveying Construction Administration District Services October 20, 2017 City of Thornton Attn: Tim Semones Development Engineeering 9500 Civic Center Dr. Thornton, CO RE: DRAINAGE COMPLIANCE LETTER- AMBER CREEK RESIDENTIAL THORNTON, COLORADO Dear Mr. Semones: CWC Consulting Group (CWC) is submitting this letter on behalf of our client, Meritage Homes., to present the drainage analysis in support of the Conceptual Site Plan for Tallgrass Self Storage located within the Amber Creek Filing No. 1 subdivision. A Final Drainage Report will be submitted with the Final Plat. The purpose of this letter is to demonstrate that the proposed drainage for this project conforms with the City of Thornton Standards and Specifications Section 400 and the Master Drainage Study for Amber Creek Detention and Water Quality Pond in Tract B-A by MM&D Service, LLC dated 03/12/17. The project is located on approximately 12.9 acres located between E. 134 th Ave, Newport Street and the King Soopers site. The project is referred to as acres of Duplex Zoning in the master drainage report. This project is also part of a 2.33 acre Commercial area identified in the master drainage report. The Duplex area was designated as 45% and the Commercial area was designates as 87% for a total composite impervious coverage value of 13.3 acres at 52.4 %. The existing site generally slopes form southwest to northeast and has had soil stockpiles placed on-site from adjacent development. Newport Street and E. 134 th Ave. have been constructed. And residential homes are currently being constructed to the south. The King Soopers site is going through the CSP process slightly ahead of this project. Coordination between both projects is ongoing and the King Soopers site will construct storm sewer infrastructure that receives runoff from this project. There is also a portion of this project that drains directly to the King Soopers site that will need to be analyzed by the King Soopers project. A 30 storm sewer stub designed as part of the Amber Creek Phase 4 and 5 project located to the northwest will be extended through this project to the King Soopers site. The proposed on-site drainage basins for this project total acres at 51.9% impervious. There is an additional 1.09 acres at 11.7% impervious that drains directly off-site to King Soopers. This brings the overall project to acres at a composite impervious value of 48.6% which is less than the master drainage plan value of 13.3 acres at 52.4%. The combined Runoff coefficients are 0.43 for the 5-yr event and 0.69 for the 100-yr event. The on-site basins are developed to represent the drainage area being conveyed to key infrastructure. Basins A, B, C and D all drain to the King Soopers storm sewer system. Basins E and F drain directly to the detention/wq pond located in Tract B-A which is designed in the master drainage report but not yet constructed. Basin OS are basins either draining from off-site areas or to off-site areas. CWC Consulting Group 9360 Teddy Lane, Suite 203 Lone Tree Colorado

2 Basin A is 0.86 acres in size and has an impervious coverage value of 62.5%. When combined with Basin OS-1, this area is 7.93 acres. The basin discharges 9.5 cfs during the 5-yr storm and 29.9 cfs during the 100-yr storm including flows from Basin OS-1. Basin B is 1.30 acres in size and has an impervious coverage value of 63.6%. The basin discharges 2.6 cfs during the 5-yr storm and 6.9 cfs during the 100-yr storm. Basin C is 2.60 acres in size and has an impervious coverage value of 56.4%. The basin discharges 4.8 cfs during the 5-yr storm and 13.3 cfs during the 100-yr storm. Basin D is 3.15 acres in size and has an impervious coverage value of 45.9%. The basin discharges 4.5 cfs during the 5-yr storm and 14.3 cfs during the 100-yr storm. Basin E is 2.55 acres in size and has an impervious coverage value of 51.2%. The basin discharges 4.2 cfs during the 5-yr storm and 12.5 cfs during the 100-yr storm. Basin F is 1.57 acres in size and has an impervious coverage value of 41.8%. The basin discharges 2.1 cfs during the 5-yr storm and 7.8 cfs during the 100-yr storm. The combined Basins E and F discharge 6.1 cfs in the 5-yr event and 19.7 cfs in the 100-yr event directly to the pond. Basin OS-1 is 7.07 acres in size and has an impervious coverage value of 45.0% as obtained from the master drainage report. The basin discharges 8.2 cfs during the 5-yr storm and 26.6 cfs during the 100-yr storm. Basin OS-2 is 1.09 acres in size and has an impervious coverage value of 11.7%. Runoff is not analyzed for this basin since it flows directly to the King Soopers site. Runoff coefficients are obtained from the latest Urban Drainage criteria (March 2017) with the exception of Basin OS-1 which utilized the master drainage plan values. The private street capacities were determined using the City standard Local Attached curb and gutter per DWG The streets are 26 wide flowline to flowline and the 5- yr allowable street depth is 4 to the top of curb and the allowable 100-yr street depth is 5 to the back of walk. Inlets are placed prior to the streets exceeding allowable capacity and bypass flows for runoff in excess of inlet capacity is placed at the downstream inlet. I affirm that the proposed drainage design for the Amber Creek Residential project is in substantial conformance with the Master Drainage Study for Amber Creek Detention and Water Quality Pond in Tract B-A by MM&D Service, LLC dated 03/12/17. Respectfully, Bryan Clerico, P.E. SIGNATURE: Registered Professional Engineer State of Colorado No (Affix Seal)

3 Table 6-5. Runoff coefficients, c (continued) Total or Effective NRCS Hydrologic Soil Group C % Impervious 2-Year 5-Year 10-Year 25-Year 50-Year 100-Year 500-Year 2% % % % % % % % % % % % % % % % % % % % % Figure 6-1. Runoff coefficient vs. watershed imperviousness NRCS HSG A March 2017 Urban Drainage and Flood Control District 6-11 Urban Storm Drainage Criteria Manual Volume 1

4 Parcel Data Table Fully-Developed Conditions 10/19/17 Job No.: Date: 10/19/2017 Calculated By: Checked By: Parcel Data Table ONSITE AREAS: Area Land Use Density C2 C5 C10 C100 I (%) Category DU/acre Street/Pond Paved/Pond Trail/Sidewalks Concrete Multi Unit Detached Residential Single Family Residential Roof Roof Open Space Tree Lawn, Open Space Imperviousness values and Runoff Coefficients are from the UDFCD Manual Volume 1 Table 6-5 Imperviousness values and Runoff Coefficients are from MM&D Engineering Services Master Plan T:\JOBS\Meritage\Amber Creek\Engineering\Drainage\CSP\Hydrology\[.xlsx]Parcel Data

5 Composite Imperviousness Fully Developed Conditions 10/19/2017 Job No.: Date: Calculated By: Checked By: /19/17 ELS BEC Parcel Imperviousness Basin Sub-Basin Area Street/Pond Trail/Sidewalks Multi Unit Detached Single Family Roof Open Space Composite Imperviousness A (acres) A Sum B B B B Sum C C C C C Sum D D D D D D Sum E E E E Sum F F F F Sum On-Site Sum OS OS Sum OS OS Sum T:\JOBS\Meritage\Amber Creek\Engineering\Drainage\CSP\FIRST\Hydrology\[.xlsx]Summary

6 Composite Runoff Coeffient 10/19/2017 Job No.: Date: Calculated By: Checked By: /19/ Year Calculation 5 Year Calculation 10 Year Calculation 100 Year Calculation Area Type Area Type Area Type Area Type Basin Sub-Basin Area Street/Pond Trail/Sidewalks Multi Unit Detached Single Family Roof Open Space Street/Pond Trail/Sidewalks Multi Unit Detached Single Family Roof Open Space C2 C5 C10 Street/Pond Trail/Sidewalks Multi Unit Detached Single Family Roof Open Space Street/Pond Trail/Sidewalks Multi Unit Detached Single Family Roof Open Space (ac) A A B B B B C C C C C D D D D D D E E E E F F F F COMPOSITE OS OS OS OS T:\JOBS\Meritage\Amber Creek\Engineering\Drainage\CSP\FIRST\Hydrology\[.xlsx]Summary C100

7 TIME OF CONCENTRATION Developed Conditions 10/19/2017 Job No.: Date: 10/19/17 Calculated By: Checked By: BEC BEC SUB-BASIN DATA INITIAL/OVERLAND TRAVEL TIME Rational Tc Check for Urban Catchments FINAL Tc TIME (Ti) (Tt) Tc CONVEYANCE DESIG: AREA C5 LENGTH SLOPE Ti LENGTH AVG. SLOPE Conv. VEL Tt COMP TOTAL Tc=(L/180)+10 REMARKS (acres) (ft) (ft/ft) (min) (ft) Y (%) Type* (fps) (min) Tc (min) LENGTH (ft) (min) (min) A Paved Gutter B Paved Gutter B Paved Gutter B Paved Gutter C Paved Gutter C Paved Gutter C Paved Gutter C Paved Gutter D Paved Gutter D Paved Gutter D Grass Swale D D Paved Gutter E E Paved Gutter E Paved Gutter F Grass Swale F Paved Gutter F Paved Gutter OS MM&D Master Plan value Derived from MM&D Master Plan area, flow and impervious value to back into time of concentration * Note: Conveyance Coefficients - Type 1-Heavy Meadow, Type 2-Tillage/field, Type 3-Short Pasture & Lawn, Type 4-Nearly Bare Ground, Type 5-Grassed Waterway, Type 6-Paved Areas & Shallow Paved Swales. Ti= 0.395(1.1-C 5 )L 0.5 S 0.33 T:\JOBS\Meritage\Amber Creek\Engineering\Drainage\CSP\Hydrology\[.xlsx]Parcel Data

8 Rainfall Intensities STANDARD FORM SF-2 STORM DRAINAGE SYSTEM DESIGN I=28.5*P1/(10+Tc).0786 (RATIONAL METHOD PROCEDURE) DESIGN STORM: 5 -YEAR (minor storm) 5-year P1 = 1.38 CALCULATED BY: BEC PROJECT: JOB NO: CHECKED BY: BEC MAJOR BASIN: LOCATION: Thornton DIRECT RUNOFF TOTAL RUNOFF STREET PIPE TRAVEL TIME LOCATION DESIGN POINT AREA DESIG. AREA (Acres) RUNOFF COEFF Tc (min) C A (Acres) I (in/hour) Q (cfs) Tc (min) (C A) (Acres) I (in/hour) Q (cfs) SLOPE (%) STREET FLOW (cfs) DESIGN FLOW (cfs) SLOPE (%) PIPE SIZE LENGTH (ft) VELOCITY (fps) Tt (min) REMARKS OS OS OS Flow from MM&D Engineering Master Plan A A1 A Pipe flow to JP 1 Surface flow to inlet at DP A1 inc. upstream bypass B B1 B Surface flow to inlet at DP B1 ~ Bypass street flow to DP A1, Pipe flow to JP 2 B B2 B Surface flow to inlet at DP B2 ~ 0.00 Bypass street flow to DP B3 B B3 B Surface flow to inlet at DP B3 inc. upstream bypass C C1 C Surface flow to inlet at DP C1 ~ Bypass street flow to DP D1, Pipe flow to JP 4 C C2 C Surface flow to inlet at DP C2 C C3 C Surface flow to inlet at DP C3 ~ 0.00 Bypass street flow to DP C4 C C4 C Surface flow to inlet at DP C4 inc. upstream bypass Pipe flow to JP 6 D D1 D Surface flow to inlet at DP D1 inc. upstream bypass Pipe flow to JP 7 D D2 D Surface flow to inlet at DP D2 ~ 0.00 Bypass street flow to DP E2 D D3 D Surface flow to inlet at DP D3 D D4 D Surface flow to inlet at DP D4 D D5 D Surface flow to inlet at DP D5 E E1 E Surface flow to inlet at DP E1 inc. upstream bypass ~ 0.00 Bypass street flow to DP F2 E E2 E Surface flow to inlet at DP E2 ~ Bypass street flow to DP E1,Pipe flow to JP 11 E E3 E Surface flow to inlet at DP E3 ~ 0.07 Bypass street flow to DP F2 F F1 F Surface flow to inlet at DP F Pipe flow to JP 12 F F2 F Surface flow to inlet at DP F2 inc. upstream bypass F F3 F Surface flow to inlet at DP F3 jp 1 A1, OS jp 2 B1,B jp 3 B1,B2, B jp 4 C1,C jp 5 C1, C2, C Pipe flow to JP KS Pipe flow to JP 3 inc. downstream bypass Pipe flow to JP KS Pipe flow to JP 5 inc. downstream bypass Pipe flow to JP 5 inc. downstream bypass

9 Rainfall Intensities STANDARD FORM SF-2 STORM DRAINAGE SYSTEM DESIGN I=28.5*P1/(10+Tc).0786 (RATIONAL METHOD PROCEDURE) DESIGN STORM: 5 -YEAR (minor storm) 5-year P1 = 1.38 CALCULATED BY: BEC PROJECT: JOB NO: CHECKED BY: BEC MAJOR BASIN: LOCATION: Thornton DIRECT RUNOFF TOTAL RUNOFF STREET PIPE TRAVEL TIME LOCATION DESIGN POINT AREA DESIG. AREA (Acres) RUNOFF COEFF Tc (min) C A (Acres) I (in/hour) Q (cfs) Tc (min) (C A) (Acres) I (in/hour) Q (cfs) SLOPE (%) STREET FLOW (cfs) DESIGN FLOW (cfs) SLOPE (%) PIPE SIZE LENGTH (ft) VELOCITY (fps) Tt (min) REMARKS jp 6 C1, C2, C3, C jp 7 D1, D jp 8 D1, D2, D jp 9 D1, D2, D3, D jp 10 D1, D2, D3, D4, D jp 11 E1, E jp 12 E1, E2, E jp 13 F1, F jp 14 F1, F2, F jp 15 E1, E2, E3, F1, F2, F Pipe flow to JP KS Pipe flow to JP 8 inc. downstream bypass Pipe flow to JP Pipe flow to JP Pipe flow to JP KS Pipe flow to JP 15 inc. downstream bypass Pipe flow to JP 13 inc. downstream bypass Pipe flow to JP Pipe flow to JP Pipe flow to Pond T:\JOBS\Meritage\Amber Creek\Engineering\Drainage\CSP\Hydrology\[.xlsx]R5 Intensity -Duration Curve for Rational Method per equation RA-3 (Urban Drainage) 7.07 Acres from MM&D Engineering Services Master Plan 26.6 CFS from MM&D Engineering Services Master Plan ~ Indicates street flow

10 Rainfall Intensities STANDARD FORM SF-2 STORM DRAINAGE SYSTEM DESIGN I=28.5*P1/(10+Tc).0786 (RATIONAL METHOD PROCEDURE) DESIGN STORM: 100 -YEAR (major storm) 100-year P1 = 2.69 CALCULATED BY: BEC PROJECT: JOB NO: CHECKED BY: BEC MAJOR BASIN: LOCATION: Thornton DIRECT RUNOFF TOTAL RUNOFF STREET PIPE TRAVEL TIME LOCATION DESIGN POINT AREA DESIG. AREA (Acres) RUNOFF COEFF Tc (min) C A (Acres) I (in/hour) Q (cfs) Tc (min) (C A) (Acres) I (in/hour) Q (cfs) SLOPE (%) STREET FLOW (cfs) DESIGN FLOW (cfs) SLOPE (%) PIPE SIZE LENGTH (ft) VELOCITY (fps) Tt (min) REMARKS OS OS OS Flow from MM&D Engineering Master Plan A A1 A Pipe flow to JP 1 Surface flow to inlet at DP A1 inc. upstream bypass B B1 B Surface flow to inlet at DP B1 ~ Bypass street flow to DP A1, Pipe flow to JP 2 B B2 B Surface flow to inlet at DP B2 ~ 0.14 Bypass street flow to DP B3 B B3 B Surface flow to inlet at DP B3 inc. upstream bypass C C1 C Surface flow to inlet at DP C1 ~ Bypass street flow to DP D1, Pipe flow to JP 4 C C2 C Surface flow to inlet at DP C2 C C3 C Surface flow to inlet at DP C3 ~ 0.58 Bypass street flow to DP C4 C C4 C Surface flow to inlet at DP C4 inc. upstream bypass Pipe flow to JP 6 D D1 D Surface flow to inlet at DP D1 inc. upstream bypass D D2 D Pipe flow to JP 7 Surface flow to inlet at DP D2 ~ 0.20 Bypass street flow to DP E2 D D3 D Surface flow to inlet at DP D3 D D4 D Surface flow to inlet at DP D4 D D5 D Surface flow to inlet at DP D5 E E1 E Surface flow to inlet at DP E1 inc. upstream bypass ~ 0.08 Bypass street flow to DP F2 E E2 E Surface flow to inlet at DP E2 ~ Bypass street flow to DP E1,Pipe flow to JP 11 E E3 E Surface flow to inlet at DP E3 ~ 1.75 Bypass street flow to DP F2 F F1 F Surface flow to inlet at DP F Pipe flow to JP 12 F F2 F Surface flow to inlet at DP F2 inc. upstream bypass F F3 F Surface flow to inlet at DP F3 jp 1 A1, OS jp 2 B1,B jp 3 B1,B2, B jp 4 C1,C jp 5 C1, C2, C Pipe flow to JP KS Pipe flow to JP 3 inc. downstream bypass Pipe flow to JP KS Pipe flow to JP 5 inc. downstream bypass Pipe flow to JP 5 inc. downstream bypass

11 Rainfall Intensities STANDARD FORM SF-2 STORM DRAINAGE SYSTEM DESIGN I=28.5*P1/(10+Tc).0786 (RATIONAL METHOD PROCEDURE) DESIGN STORM: 100 -YEAR (major storm) 100-year P1 = 2.69 CALCULATED BY: BEC PROJECT: JOB NO: CHECKED BY: BEC MAJOR BASIN: LOCATION: Thornton DIRECT RUNOFF TOTAL RUNOFF STREET PIPE TRAVEL TIME LOCATION DESIGN POINT AREA DESIG. AREA (Acres) RUNOFF COEFF Tc (min) C A (Acres) I (in/hour) Q (cfs) Tc (min) (C A) (Acres) I (in/hour) Q (cfs) SLOPE (%) STREET FLOW (cfs) DESIGN FLOW (cfs) SLOPE (%) PIPE SIZE LENGTH (ft) VELOCITY (fps) Tt (min) REMARKS jp 6 C1, C2, C3, C jp 7 D1, D jp 8 D1, D2, D jp 9 D1, D2, D3, D jp 10 D1, D2, D3, D4, D jp 11 E1, E jp 12 E1, E2, E jp 13 F1, F jp 14 F1, F2, F jp 15 E1, E2, E3, F1, F2, F Pipe flow to JP KS Pipe flow to JP 8 inc. downstream bypass Pipe flow to JP Pipe flow to JP Pipe flow to JP KS Pipe flow to JP 15 inc. downstream bypass Pipe flow to JP 13 inc. downstream bypass Pipe flow to JP Pipe flow to JP Pipe flow to Pond T:\JOBS\Meritage\Amber Creek\Engineering\Drainage\CSP\Hydrology\[.xlsx]R5 Intensity -Duration Curve for Rational Method per equation RA-3 (Urban Drainage) 7.07 Acres from MM&D Engineering Services Master Plan 26.6 CFS from MM&D Engineering Services Master Plan ~ Indicates street flow

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13 DESIGN PEAK FLOW FOR ONE-HALF OF STREET OR GRASS-LINED CHANNEL BY THE RATIONAL METHOD Worksheet Protected Project: Inlet A1 Show Details Design Flow: ONLY if already determined through other methods: Minor Storm Major Storm (local peak flow for 1/2 of street OR grass-lined channel): *Q Known = cfs * If you enter values in Row 14, skip the rest of this sheet and proceed to sheet Q-Allow or Area Inlet. Geographic Information: (Enter data in the blue cells): Site Type: Site is Urban Site is Non-Urban Flows Developed For: Street Inlets Area Inlets in a Median Subcatchment Area = Acres Percent Imperviousness = % NRCS Soil Type = A, B, C, or D Overland Flow = Channel Flow = Slope (ft/ft) Length (ft) FILL IN THIS SECTION OR FILL IN THE SECTIONS BELOW. Rainfall Information: Intensity I (inch/hr) = C 1 * P 1 / ( C 2 + T c ) ^ C 3 Minor Storm Major Storm Design Storm Return Period, T r = Return Period One-Hour Precipitation, P 1 = C 1 = C 2 = C 3 = User-Defined Storm Runoff Coefficient (leave this blank to accept a calculated value), C = User-Defined 5-yr. Runoff Coefficient (leave this blank to accept a calculated value), C 5 = Bypass (Carry-Over) Flow from upstream Subcatchments, Q b = cfs years inches Total Design Peak Flow, Q = cfs inlet A1.xlsm, Q-Peak 10/19/2017, 2:41 PM

14 Project: ALLOWABLE CAPACITY FOR ONE-HALF OF STREET (Minor & Major Storm) (Based on Regulated Criteria for Maximum Allowable Flow Depth and Spread) Inlet A1 Gutter Geometry (Enter data in the blue cells) Maximum Allowable Width for Spread Behind Curb T BACK = 5.0 ft Side Slope Behind Curb (leave blank for no conveyance credit behind curb) S BACK = ft/ft Manning's Roughness Behind Curb (typically between and 0.020) n BACK = Height of Curb at Gutter Flow Line H CURB = 4.00 inches Distance from Curb Face to Street Crown T CROWN = 13.0 ft Gutter Width W = 2.00 ft Street Transverse Slope S X = ft/ft Gutter Cross Slope (typically 2 inches over 24 inches or ft/ft) S W = ft/ft Street Longitudinal Slope - Enter 0 for sump condition S O = ft/ft Manning's Roughness for Street Section (typically between and 0.020) n STREET = Minor Storm Major Storm Max. Allowable Spread for Minor & Major Storm T MAX = ft Max. Allowable Depth at Gutter Flowline for Minor & Major Storm d MAX = inches Allow Flow Depth at Street Crown (leave blank for no) check = yes MINOR STORM Allowable Capacity is based on Depth Criterion Minor Storm Major Storm MAJOR STORM Allowable Capacity is based on Spread Criterion Q allow = cfs Minor storm max. allowable capacity GOOD - greater than flow given on sheet 'Q-Peak' Major storm max. allowable capacity GOOD - greater than flow given on sheet 'Q-Peak' inlet A1.xlsm, Q-Allow 10/19/2017, 2:42 PM

15 INLET ON A CONTINUOUS GRADE Project: Inlet A1 Design Information (Input) MINOR MAJOR Type of Inlet Type = CDOT Type R Curb Opening Local Depression (additional to continuous gutter depression 'a' from 'Q-Allow') a LOCAL = inches Total Number of Units in the Inlet (Grate or Curb Opening) No = 2 2 Length of a Single Unit Inlet (Grate or Curb Opening) L o = ft Width of a Unit Grate (cannot be greater than W from Q-Allow) W o = N/A N/A ft Clogging Factor for a Single Unit Grate (typical min. value = 0.5) C f-g = N/A N/A Clogging Factor for a Single Unit Curb Opening (typical min. value = 0.1) C f-c = Street Hydraulics: OK - Q < maximum allowable from sheet 'Q-Allow' MINOR MAJOR Total Inlet Interception Capacity Q = cfs Total Inlet Carry-Over Flow (flow bypassing inlet) Q b = cfs Capture Percentage = Q a/q o = C% = % inlet A1.xlsm, Inlet On Grade 10/19/2017, 2:42 PM

16 DESIGN PEAK FLOW FOR ONE-HALF OF STREET OR GRASS-LINED CHANNEL BY THE RATIONAL METHOD Worksheet Protected Project: Inlet B1 Show Details Design Flow: ONLY if already determined through other methods: Minor Storm Major Storm (local peak flow for 1/2 of street OR grass-lined channel): *Q Known = cfs * If you enter values in Row 14, skip the rest of this sheet and proceed to sheet Q-Allow or Area Inlet. Geographic Information: (Enter data in the blue cells): Site Type: Site is Urban Site is Non-Urban Flows Developed For: Street Inlets Area Inlets in a Median Subcatchment Area = Acres Percent Imperviousness = % NRCS Soil Type = A, B, C, or D Overland Flow = Channel Flow = Slope (ft/ft) Length (ft) FILL IN THIS SECTION OR FILL IN THE SECTIONS BELOW. Rainfall Information: Intensity I (inch/hr) = C 1 * P 1 / ( C 2 + T c ) ^ C 3 Minor Storm Major Storm Design Storm Return Period, T r = Return Period One-Hour Precipitation, P 1 = C 1 = C 2 = C 3 = User-Defined Storm Runoff Coefficient (leave this blank to accept a calculated value), C = User-Defined 5-yr. Runoff Coefficient (leave this blank to accept a calculated value), C 5 = Bypass (Carry-Over) Flow from upstream Subcatchments, Q b = years inches cfs Total Design Peak Flow, Q = cfs inlet B1.xlsm, Q-Peak 10/19/2017, 2:29 PM

17 Project: ALLOWABLE CAPACITY FOR ONE-HALF OF STREET (Minor & Major Storm) (Based on Regulated Criteria for Maximum Allowable Flow Depth and Spread) Inlet B1 Gutter Geometry (Enter data in the blue cells) Maximum Allowable Width for Spread Behind Curb T BACK = 5.0 ft Side Slope Behind Curb (leave blank for no conveyance credit behind curb) S BACK = ft/ft Manning's Roughness Behind Curb (typically between and 0.020) n BACK = Height of Curb at Gutter Flow Line H CURB = 4.00 inches Distance from Curb Face to Street Crown T CROWN = 13.0 ft Gutter Width W = 2.00 ft Street Transverse Slope S X = ft/ft Gutter Cross Slope (typically 2 inches over 24 inches or ft/ft) S W = ft/ft Street Longitudinal Slope - Enter 0 for sump condition S O = ft/ft Manning's Roughness for Street Section (typically between and 0.020) n STREET = Minor Storm Major Storm Max. Allowable Spread for Minor & Major Storm T MAX = ft Max. Allowable Depth at Gutter Flowline for Minor & Major Storm d MAX = inches Allow Flow Depth at Street Crown (leave blank for no) check = yes MINOR STORM Allowable Capacity is based on Depth Criterion Minor Storm Major Storm MAJOR STORM Allowable Capacity is based on Spread Criterion Q allow = cfs Minor storm max. allowable capacity GOOD - greater than flow given on sheet 'Q-Peak' Major storm max. allowable capacity GOOD - greater than flow given on sheet 'Q-Peak' inlet B1.xlsm, Q-Allow 10/19/2017, 2:30 PM

18 INLET ON A CONTINUOUS GRADE Project: Inlet B1 Design Information (Input) MINOR MAJOR Type of Inlet Type = CDOT Type R Curb Opening Local Depression (additional to continuous gutter depression 'a' from 'Q-Allow') a LOCAL = inches Total Number of Units in the Inlet (Grate or Curb Opening) No = 2 2 Length of a Single Unit Inlet (Grate or Curb Opening) L o = ft Width of a Unit Grate (cannot be greater than W from Q-Allow) W o = N/A N/A ft Clogging Factor for a Single Unit Grate (typical min. value = 0.5) C f-g = N/A N/A Clogging Factor for a Single Unit Curb Opening (typical min. value = 0.1) C f-c = Street Hydraulics: OK - Q < maximum allowable from sheet 'Q-Allow' MINOR MAJOR Total Inlet Interception Capacity Q = cfs Total Inlet Carry-Over Flow (flow bypassing inlet) Q b = cfs Capture Percentage = Q a/q o = C% = % inlet B1.xlsm, Inlet On Grade 10/19/2017, 2:31 PM

19 DESIGN PEAK FLOW FOR ONE-HALF OF STREET OR GRASS-LINED CHANNEL BY THE RATIONAL METHOD Worksheet Protected Project: Inlet B2 Show Details Design Flow: ONLY if already determined through other methods: Minor Storm Major Storm (local peak flow for 1/2 of street OR grass-lined channel): *Q Known = cfs * If you enter values in Row 14, skip the rest of this sheet and proceed to sheet Q-Allow or Area Inlet. Geographic Information: (Enter data in the blue cells): Site Type: Site is Urban Site is Non-Urban Flows Developed For: Street Inlets Area Inlets in a Median Subcatchment Area = Acres Percent Imperviousness = % NRCS Soil Type = A, B, C, or D Overland Flow = Channel Flow = Slope (ft/ft) Length (ft) FILL IN THIS SECTION OR FILL IN THE SECTIONS BELOW. Rainfall Information: Intensity I (inch/hr) = C 1 * P 1 / ( C 2 + T c ) ^ C 3 Minor Storm Major Storm Design Storm Return Period, T r = Return Period One-Hour Precipitation, P 1 = C 1 = C 2 = C 3 = User-Defined Storm Runoff Coefficient (leave this blank to accept a calculated value), C = User-Defined 5-yr. Runoff Coefficient (leave this blank to accept a calculated value), C 5 = Bypass (Carry-Over) Flow from upstream Subcatchments, Q b = years inches cfs Total Design Peak Flow, Q = cfs inlet B2.xlsm, Q-Peak 10/19/2017, 2:34 PM

20 Project: ALLOWABLE CAPACITY FOR ONE-HALF OF STREET (Minor & Major Storm) (Based on Regulated Criteria for Maximum Allowable Flow Depth and Spread) Inlet B2 Gutter Geometry (Enter data in the blue cells) Maximum Allowable Width for Spread Behind Curb T BACK = 5.0 ft Side Slope Behind Curb (leave blank for no conveyance credit behind curb) S BACK = ft/ft Manning's Roughness Behind Curb (typically between and 0.020) n BACK = Height of Curb at Gutter Flow Line H CURB = 4.00 inches Distance from Curb Face to Street Crown T CROWN = 13.0 ft Gutter Width W = 2.00 ft Street Transverse Slope S X = ft/ft Gutter Cross Slope (typically 2 inches over 24 inches or ft/ft) S W = ft/ft Street Longitudinal Slope - Enter 0 for sump condition S O = ft/ft Manning's Roughness for Street Section (typically between and 0.020) n STREET = Minor Storm Major Storm Max. Allowable Spread for Minor & Major Storm T MAX = ft Max. Allowable Depth at Gutter Flowline for Minor & Major Storm d MAX = inches Allow Flow Depth at Street Crown (leave blank for no) check = yes MINOR STORM Allowable Capacity is based on Depth Criterion Minor Storm Major Storm MAJOR STORM Allowable Capacity is based on Spread Criterion Q allow = cfs Minor storm max. allowable capacity GOOD - greater than flow given on sheet 'Q-Peak' Major storm max. allowable capacity GOOD - greater than flow given on sheet 'Q-Peak' inlet B2.xlsm, Q-Allow 10/19/2017, 2:35 PM

21 INLET ON A CONTINUOUS GRADE Project: Inlet B2 Design Information (Input) MINOR MAJOR Type of Inlet Type = CDOT Type R Curb Opening Local Depression (additional to continuous gutter depression 'a' from 'Q-Allow') a LOCAL = inches Total Number of Units in the Inlet (Grate or Curb Opening) No = 1 1 Length of a Single Unit Inlet (Grate or Curb Opening) L o = ft Width of a Unit Grate (cannot be greater than W from Q-Allow) W o = N/A N/A ft Clogging Factor for a Single Unit Grate (typical min. value = 0.5) C f-g = N/A N/A Clogging Factor for a Single Unit Curb Opening (typical min. value = 0.1) C f-c = Street Hydraulics: OK - Q < maximum allowable from sheet 'Q-Allow' MINOR MAJOR Total Inlet Interception Capacity Q = cfs Total Inlet Carry-Over Flow (flow bypassing inlet) Q b = cfs Capture Percentage = Q a/q o = C% = % inlet B2.xlsm, Inlet On Grade 10/19/2017, 2:35 PM

22 DESIGN PEAK FLOW FOR ONE-HALF OF STREET OR GRASS-LINED CHANNEL BY THE RATIONAL METHOD Worksheet Protected Project: Inlet B3 Show Details Design Flow: ONLY if already determined through other methods: Minor Storm Major Storm (local peak flow for 1/2 of street OR grass-lined channel): *Q Known = cfs * If you enter values in Row 14, skip the rest of this sheet and proceed to sheet Q-Allow or Area Inlet. Geographic Information: (Enter data in the blue cells): Site Type: Site is Urban Site is Non-Urban Flows Developed For: Street Inlets Area Inlets in a Median Subcatchment Area = Acres Percent Imperviousness = % NRCS Soil Type = A, B, C, or D Overland Flow = Channel Flow = Slope (ft/ft) Length (ft) FILL IN THIS SECTION OR FILL IN THE SECTIONS BELOW. Rainfall Information: Intensity I (inch/hr) = C 1 * P 1 / ( C 2 + T c ) ^ C 3 Minor Storm Major Storm Design Storm Return Period, T r = Return Period One-Hour Precipitation, P 1 = C 1 = C 2 = C 3 = User-Defined Storm Runoff Coefficient (leave this blank to accept a calculated value), C = User-Defined 5-yr. Runoff Coefficient (leave this blank to accept a calculated value), C 5 = Bypass (Carry-Over) Flow from upstream Subcatchments, Q b = cfs years inches Total Design Peak Flow, Q = cfs inlet B3.xlsm, Q-Peak 10/19/2017, 2:36 PM

23 Project: ALLOWABLE CAPACITY FOR ONE-HALF OF STREET (Minor & Major Storm) (Based on Regulated Criteria for Maximum Allowable Flow Depth and Spread) Inlet B3 Gutter Geometry (Enter data in the blue cells) Maximum Allowable Width for Spread Behind Curb T BACK = 5.0 ft Side Slope Behind Curb (leave blank for no conveyance credit behind curb) S BACK = ft/ft Manning's Roughness Behind Curb (typically between and 0.020) n BACK = Height of Curb at Gutter Flow Line H CURB = 4.00 inches Distance from Curb Face to Street Crown T CROWN = 13.0 ft Gutter Width W = 2.00 ft Street Transverse Slope S X = ft/ft Gutter Cross Slope (typically 2 inches over 24 inches or ft/ft) S W = ft/ft Street Longitudinal Slope - Enter 0 for sump condition S O = ft/ft Manning's Roughness for Street Section (typically between and 0.020) n STREET = Minor Storm Major Storm Max. Allowable Spread for Minor & Major Storm T MAX = ft Max. Allowable Depth at Gutter Flowline for Minor & Major Storm d MAX = inches Allow Flow Depth at Street Crown (leave blank for no) check = yes MINOR STORM Allowable Capacity is based on Depth Criterion Minor Storm Major Storm MAJOR STORM Allowable Capacity is based on Spread Criterion Q allow = cfs Minor storm max. allowable capacity GOOD - greater than flow given on sheet 'Q-Peak' Major storm max. allowable capacity GOOD - greater than flow given on sheet 'Q-Peak' inlet B3.xlsm, Q-Allow 10/19/2017, 2:37 PM

24 INLET ON A CONTINUOUS GRADE Project: Inlet B3 Design Information (Input) MINOR MAJOR Type of Inlet Type = CDOT Type R Curb Opening Local Depression (additional to continuous gutter depression 'a' from 'Q-Allow') a LOCAL = inches Total Number of Units in the Inlet (Grate or Curb Opening) No = 1 1 Length of a Single Unit Inlet (Grate or Curb Opening) L o = ft Width of a Unit Grate (cannot be greater than W from Q-Allow) W o = N/A N/A ft Clogging Factor for a Single Unit Grate (typical min. value = 0.5) C f-g = N/A N/A Clogging Factor for a Single Unit Curb Opening (typical min. value = 0.1) C f-c = Street Hydraulics: OK - Q < maximum allowable from sheet 'Q-Allow' MINOR MAJOR Total Inlet Interception Capacity Q = cfs Total Inlet Carry-Over Flow (flow bypassing inlet) Q b = cfs Capture Percentage = Q a/q o = C% = % inlet B3.xlsm, Inlet On Grade 10/19/2017, 2:38 PM

25 DESIGN PEAK FLOW FOR ONE-HALF OF STREET OR GRASS-LINED CHANNEL BY THE RATIONAL METHOD Worksheet Protected Project: Inlet C1 Show Details Design Flow: ONLY if already determined through other methods: Minor Storm Major Storm (local peak flow for 1/2 of street OR grass-lined channel): *Q Known = cfs * If you enter values in Row 14, skip the rest of this sheet and proceed to sheet Q-Allow or Area Inlet. Geographic Information: (Enter data in the blue cells): Site Type: Site is Urban Site is Non-Urban Flows Developed For: Street Inlets Area Inlets in a Median Subcatchment Area = Acres Percent Imperviousness = % NRCS Soil Type = A, B, C, or D Overland Flow = Channel Flow = Slope (ft/ft) Length (ft) FILL IN THIS SECTION OR FILL IN THE SECTIONS BELOW. Rainfall Information: Intensity I (inch/hr) = C 1 * P 1 / ( C 2 + T c ) ^ C 3 Minor Storm Major Storm Design Storm Return Period, T r = Return Period One-Hour Precipitation, P 1 = C 1 = C 2 = C 3 = User-Defined Storm Runoff Coefficient (leave this blank to accept a calculated value), C = User-Defined 5-yr. Runoff Coefficient (leave this blank to accept a calculated value), C 5 = Bypass (Carry-Over) Flow from upstream Subcatchments, Q b = years inches cfs Total Design Peak Flow, Q = cfs inlet C1.xlsm, Q-Peak 10/19/2017, 2:47 PM

26 Project: ALLOWABLE CAPACITY FOR ONE-HALF OF STREET (Minor & Major Storm) (Based on Regulated Criteria for Maximum Allowable Flow Depth and Spread) Inlet C1 Gutter Geometry (Enter data in the blue cells) Maximum Allowable Width for Spread Behind Curb T BACK = 5.0 ft Side Slope Behind Curb (leave blank for no conveyance credit behind curb) S BACK = ft/ft Manning's Roughness Behind Curb (typically between and 0.020) n BACK = Height of Curb at Gutter Flow Line H CURB = 4.00 inches Distance from Curb Face to Street Crown T CROWN = 13.0 ft Gutter Width W = 2.00 ft Street Transverse Slope S X = ft/ft Gutter Cross Slope (typically 2 inches over 24 inches or ft/ft) S W = ft/ft Street Longitudinal Slope - Enter 0 for sump condition S O = ft/ft Manning's Roughness for Street Section (typically between and 0.020) n STREET = Minor Storm Major Storm Max. Allowable Spread for Minor & Major Storm T MAX = ft Max. Allowable Depth at Gutter Flowline for Minor & Major Storm d MAX = inches Allow Flow Depth at Street Crown (leave blank for no) check = yes MINOR STORM Allowable Capacity is based on Depth Criterion Minor Storm Major Storm MAJOR STORM Allowable Capacity is based on Spread Criterion Q allow = cfs Minor storm max. allowable capacity GOOD - greater than flow given on sheet 'Q-Peak' Major storm max. allowable capacity GOOD - greater than flow given on sheet 'Q-Peak' inlet C1.xlsm, Q-Allow 10/19/2017, 2:47 PM

27 INLET ON A CONTINUOUS GRADE Project: Inlet C1 Design Information (Input) MINOR MAJOR Type of Inlet Type = CDOT Type R Curb Opening Local Depression (additional to continuous gutter depression 'a' from 'Q-Allow') a LOCAL = inches Total Number of Units in the Inlet (Grate or Curb Opening) No = 2 2 Length of a Single Unit Inlet (Grate or Curb Opening) L o = ft Width of a Unit Grate (cannot be greater than W from Q-Allow) W o = N/A N/A ft Clogging Factor for a Single Unit Grate (typical min. value = 0.5) C f-g = N/A N/A Clogging Factor for a Single Unit Curb Opening (typical min. value = 0.1) C f-c = Street Hydraulics: OK - Q < maximum allowable from sheet 'Q-Allow' MINOR MAJOR Total Inlet Interception Capacity Q = cfs Total Inlet Carry-Over Flow (flow bypassing inlet) Q b = cfs Capture Percentage = Q a/q o = C% = % inlet C1.xlsm, Inlet On Grade 10/19/2017, 2:48 PM

28 DESIGN PEAK FLOW FOR ONE-HALF OF STREET OR GRASS-LINED CHANNEL BY THE RATIONAL METHOD Worksheet Protected Project: Inlet C2 Show Details Design Flow: ONLY if already determined through other methods: Minor Storm Major Storm (local peak flow for 1/2 of street OR grass-lined channel): *Q Known = cfs * If you enter values in Row 14, skip the rest of this sheet and proceed to sheet Q-Allow or Area Inlet. Geographic Information: (Enter data in the blue cells): Site Type: Site is Urban Site is Non-Urban Flows Developed For: Street Inlets Area Inlets in a Median Subcatchment Area = Acres Percent Imperviousness = % NRCS Soil Type = A, B, C, or D Overland Flow = Channel Flow = Slope (ft/ft) Length (ft) FILL IN THIS SECTION OR FILL IN THE SECTIONS BELOW. Rainfall Information: Intensity I (inch/hr) = C 1 * P 1 / ( C 2 + T c ) ^ C 3 Minor Storm Major Storm Design Storm Return Period, T r = Return Period One-Hour Precipitation, P 1 = C 1 = C 2 = C 3 = User-Defined Storm Runoff Coefficient (leave this blank to accept a calculated value), C = User-Defined 5-yr. Runoff Coefficient (leave this blank to accept a calculated value), C 5 = Bypass (Carry-Over) Flow from upstream Subcatchments, Q b = years inches cfs Total Design Peak Flow, Q = cfs inlet C2.xlsm, Q-Peak 10/19/2017, 2:49 PM

29 Project: ALLOWABLE CAPACITY FOR ONE-HALF OF STREET (Minor & Major Storm) (Based on Regulated Criteria for Maximum Allowable Flow Depth and Spread) Inlet C2 Gutter Geometry (Enter data in the blue cells) Maximum Allowable Width for Spread Behind Curb T BACK = 5.0 ft Side Slope Behind Curb (leave blank for no conveyance credit behind curb) S BACK = ft/ft Manning's Roughness Behind Curb (typically between and 0.020) n BACK = Height of Curb at Gutter Flow Line H CURB = 4.00 inches Distance from Curb Face to Street Crown T CROWN = 13.0 ft Gutter Width W = 2.00 ft Street Transverse Slope S X = ft/ft Gutter Cross Slope (typically 2 inches over 24 inches or ft/ft) S W = ft/ft Street Longitudinal Slope - Enter 0 for sump condition S O = ft/ft Manning's Roughness for Street Section (typically between and 0.020) n STREET = Minor Storm Major Storm Max. Allowable Spread for Minor & Major Storm T MAX = ft Max. Allowable Depth at Gutter Flowline for Minor & Major Storm d MAX = inches Allow Flow Depth at Street Crown (leave blank for no) check = yes MINOR STORM Allowable Capacity is based on Depth Criterion Minor Storm Major Storm MAJOR STORM Allowable Capacity is based on Spread Criterion Q allow = cfs Minor storm max. allowable capacity GOOD - greater than flow given on sheet 'Q-Peak' Major storm max. allowable capacity GOOD - greater than flow given on sheet 'Q-Peak' inlet C2.xlsm, Q-Allow 10/19/2017, 2:50 PM

30 INLET ON A CONTINUOUS GRADE Project: Inlet C2 Design Information (Input) MINOR MAJOR Type of Inlet Type = CDOT Type R Curb Opening Local Depression (additional to continuous gutter depression 'a' from 'Q-Allow') a LOCAL = inches Total Number of Units in the Inlet (Grate or Curb Opening) No = 1 1 Length of a Single Unit Inlet (Grate or Curb Opening) L o = ft Width of a Unit Grate (cannot be greater than W from Q-Allow) W o = N/A N/A ft Clogging Factor for a Single Unit Grate (typical min. value = 0.5) C f-g = N/A N/A Clogging Factor for a Single Unit Curb Opening (typical min. value = 0.1) C f-c = Street Hydraulics: OK - Q < maximum allowable from sheet 'Q-Allow' MINOR MAJOR Total Inlet Interception Capacity Q = cfs Total Inlet Carry-Over Flow (flow bypassing inlet) Q b = cfs Capture Percentage = Q a/q o = C% = % inlet C2.xlsm, Inlet On Grade 10/19/2017, 2:52 PM

31 DESIGN PEAK FLOW FOR ONE-HALF OF STREET OR GRASS-LINED CHANNEL BY THE RATIONAL METHOD Worksheet Protected Project: Inlet C3 Show Details Design Flow: ONLY if already determined through other methods: Minor Storm Major Storm (local peak flow for 1/2 of street OR grass-lined channel): *Q Known = cfs * If you enter values in Row 14, skip the rest of this sheet and proceed to sheet Q-Allow or Area Inlet. Geographic Information: (Enter data in the blue cells): Site Type: Site is Urban Site is Non-Urban Flows Developed For: Street Inlets Area Inlets in a Median Subcatchment Area = Acres Percent Imperviousness = % NRCS Soil Type = A, B, C, or D Overland Flow = Channel Flow = Slope (ft/ft) Length (ft) FILL IN THIS SECTION OR FILL IN THE SECTIONS BELOW. Rainfall Information: Intensity I (inch/hr) = C 1 * P 1 / ( C 2 + T c ) ^ C 3 Minor Storm Major Storm Design Storm Return Period, T r = Return Period One-Hour Precipitation, P 1 = C 1 = C 2 = C 3 = User-Defined Storm Runoff Coefficient (leave this blank to accept a calculated value), C = User-Defined 5-yr. Runoff Coefficient (leave this blank to accept a calculated value), C 5 = Bypass (Carry-Over) Flow from upstream Subcatchments, Q b = years inches cfs Total Design Peak Flow, Q = cfs inlet C3.xlsm, Q-Peak 10/19/2017, 2:53 PM

32 Project: ALLOWABLE CAPACITY FOR ONE-HALF OF STREET (Minor & Major Storm) (Based on Regulated Criteria for Maximum Allowable Flow Depth and Spread) Inlet C3 Gutter Geometry (Enter data in the blue cells) Maximum Allowable Width for Spread Behind Curb T BACK = 5.0 ft Side Slope Behind Curb (leave blank for no conveyance credit behind curb) S BACK = ft/ft Manning's Roughness Behind Curb (typically between and 0.020) n BACK = Height of Curb at Gutter Flow Line H CURB = 4.00 inches Distance from Curb Face to Street Crown T CROWN = 13.0 ft Gutter Width W = 2.00 ft Street Transverse Slope S X = ft/ft Gutter Cross Slope (typically 2 inches over 24 inches or ft/ft) S W = ft/ft Street Longitudinal Slope - Enter 0 for sump condition S O = ft/ft Manning's Roughness for Street Section (typically between and 0.020) n STREET = Minor Storm Major Storm Max. Allowable Spread for Minor & Major Storm T MAX = ft Max. Allowable Depth at Gutter Flowline for Minor & Major Storm d MAX = inches Allow Flow Depth at Street Crown (leave blank for no) check = yes MINOR STORM Allowable Capacity is based on Depth Criterion Minor Storm Major Storm MAJOR STORM Allowable Capacity is based on Spread Criterion Q allow = cfs Minor storm max. allowable capacity GOOD - greater than flow given on sheet 'Q-Peak' Major storm max. allowable capacity GOOD - greater than flow given on sheet 'Q-Peak' inlet C3.xlsm, Q-Allow 10/19/2017, 2:53 PM