B08_Att_8_Final_Design_Calculations.pdf

T

B

A

R

POINT OF ANALYSIS

TRAVEL PATH

(TYP.)

WESTERN SWALE

WATERSHED

TYPE D SOIL

CRAVEN-UCHEE COMPLEX

(6 TO 10% SLOPES)

TYPE C SOIL

SLAGLE FINE SANDY LOAM

(2 TO 6% SLOPES)

TYPE C SOIL

SLAGLE FINE SANDY LOAM

(2 TO 6% SLOPES)

TYPE C SOIL

SLAGLE FINE SANDY

LOAM (2 TO 6% SLOPES)

TYPE C SOIL

SLAGLE FINE SANDY

LOAM (2 TO 6% SLOPES)

TYPE D SOIL

CRAVEN-UCHEE COMPLEX

(6 TO 10% SLOPES)

TYPE D SOIL

CRAVEN-UCHEE COMPLEX

(6 TO 10% SLOPES)

TYPE B SOIL

EMPORIA COMPLEX

(25-50% SLOPES)

C

O

L

O

N

I A

L

P

R

K

W

A

Y

L

E

U

S

S

E

U

R

D

JONES

POND

C

B

C

E

E

K

C H

A P

M A

N

R

D

L

A

K

E

S

H

E

F i l e a t h j D

W G

P

D

C i v i l F i g u r e s

D

H

Y D d w g y o u t

F

I G o t t e d

T u e

M a y

M s e r s i r o n s

LEGEND

NOTES:

DRAFT - FOR REVIEW ONLY

T

B

A

R

EASTERN SWALE

WATERSHED

POINT OF ANALYSIS

C O

LO

N

IA

L P

A R

K W

A Y

TRAVEL PATH

(TYP.)

PARKING LOT

WATERSHED

SWALE 1

PARKING LOT

WATERSHED

SWALE 2

TYPE B SOIL

EMPORIA COMPLEX

(25-50% SLOPES)

TYPE B SOIL

EMPORIA COMPLEX

(25-50% SLOPES)

TYPE D SOIL

CRAVEN-UCHEE COMPLEX

(6 TO 10% SLOPES)

TYPE D SOIL

CRAVEN-UCHEE COMPLEX

(6 TO 10% SLOPES)

TYPE D SOIL

CRAVEN-UCHEE COMPLEX

(6 TO 10% SLOPES)

TYPE B SOIL

EMPORIA FINE SANDY LOAM

(2 TO 6% SLOPES)

TYPE D SOIL

CRAVEN-UCHEE COMPLEX

(6 TO 10% SLOPES)

TYPE B SOIL

SLAGLE FINE SANDY LOAM

(2 TO 6% SLOPES)

TYPE B SOIL

EMPORIA COMPLEX

(25-50% SLOPES)

TYPE D SOIL

CRAVEN-UCHEE COMPLEX

(6 TO 10% SLOPES)

TYPE B SOIL

EMPORIA FINE SANDY LOAM

(2 TO 6% SLOPES)

C

O

L

O

N

I

R

K

W

A

Y

L

E

U

S

S

E

JONES

POND

C

B

C

E

E

K

C H

A P

M A

N

R

D

L

A

K

E

S

H

E

F i e t h j D

W G

P

D

C i v i l F i g u r e s

D

H

Y D d w g y o u t

F

I G o t t e d

T u e

M a y

M s e r s i r o n s

LEGEND

NOTES:

Jones Mill Pond Dam Colonial Parkway Repairs

Hydrologic and Hydraulic Analysis Supporting Documentation and Summary

Williamsburg, VA - April 2023

I. Subwatershed Composite Curver Number Calculations

Western Swale Subwatershed Cover Description Condition Soil Group CN No. Area (S.F.) % of Total Area Comp. CN

Impervious N/A N/A 98 85258.0 20.8 20.4

B 55 5754.0 1.4 0.8

Good C 70 220573.0 53.8 37.6

D 77 31969.0 7.8 6.0

B 61 3670.0 0.9 0.5

Good C 74 41066.0 10.0 7.4

D 80 22067.0 5.4 4.3

Totals: 410357.0 100.0 77.0

Total Area: 9.42 Acres

410357.00 SF Impervious

Eastern Swale Subwatershed Cover Description Condition Soil Group CN No. Area (S.F.) % of Total Area Comp. CN

Impervious N/A N/A 98 81517.0 15.2 14.9

B 55 184915.0 34.5 19.0

Good C 70 102206.0 19.0 13.3

D 77 100356.0 18.7 14.4

B 61 40215.0 7.5 4.6

Good C 74 8618.0 1.6 1.2

D 80 18703.0 3.5 2.8

Totals: 536530.0 100.0 70.1

Total Area: 12.32 Acres

536530.00 SF Impervious

Parking Lot Subwatershed 1 Cover Description Condition Soil Group CN No. Area (S.F.) % of Total Area Comp. CN

Impervious N/A N/A 98 3984.0 16.6 16.2

B 55 7632.0 31.7 17.5

Good C 70 585.0 2.4 1.7

D 77 7331.0 30.5 23.5

B 61 3375.0 14.0 8.6

Good C 74 0.0 0.0 0.0

D 80 1141.0 4.7 3.8

Totals: 24048.0 100.0 71.2

Total Area: 0.55 Acres

3984.00 SF Impervious

Parking Lot Subwatershed 2 Cover Description Condition Soil Group CN No. Area (S.F.) % of Total Area Comp. CN

Impervious N/A N/A 98 1415.0 83.0 81.4

Grass B 61 289.0 17.0 10.3

Totals: 1704.0 100.0 91.7

Total Area: 0.04 Acres

1415.00 SF Impervious

Woods

Grass

Woods

Grass

Woods

Grass

F:\P2009\0469\D40\Stormwater\Swale Design\SDA_SwaleCN_20230412.xlsx 5/15/2023

Williamsburg, VA - April 2023

II. End of Swale Energy Dissipation Overtopping Velocity/Depth Calculation Summary

Eastern Swale Elevation (feet) Area (sf)

Cumulative Volume

(cf) Storm Event

Overtopping Flow (cfs) -

Obtained from

Hydraflow Model

Depth of

Overtopping (ft)

Velocity of

Overtopping

Flow (ft/s)

Is Permanent Overtopping

Protection Required?

Is Permanent

Overtopping Protection

Provided?

2.0 126.0 0.0 2-Year 6.70 cfs 0.22 ft 1.22 No Yes (ACB Matting)

3.0 230.0 178.0 10-Year 16.51 cfs 0.40 ft 1.65 No Yes (ACB Matting)

4.0 360.0 473.0 100-Year 38.37 cfs 0.70 ft 2.19 No Yes (ACB Matting)

Western Swale Elevation (feet) Area (sf)

Cumulative Volume

(cf) Storm Event

Overtopping Flow (cfs) -

Obtained from

Hydraflow Model

Depth of

Overtopping (ft)

Velocity of

Overtopping

Flow (ft/s)

Is Permanent Overtopping

Protection Required?

Is Permanent

Overtopping Protection

Provided?

25.0 224.0 0.0 2-Year 8.85 cfs 0.21 ft 0.33 No Yes (ACB Matting)

26.0 380.0 302.0 10-Year 18.66 cfs 0.35 ft 0.69 No Yes (ACB Matting)

27.0 626.0 805.0 100-Year 38.90 cfs 0.57 ft 1.44 No Yes (ACB Matting)

III. Eastern Swale Hydraulic Analysis Summary

Bottom Width: 4.0 feet Velocities in red indicate computed flow velocities that exceed 3 fps (which is the maximum velocity where permanent erosion protection is not required)

Average Side Slope (H:V): 3H:1V

Average Longitudinal Slope: 13.00%

Peak Flow

(from Hydraflow)

Peak Flow Velocity

(from FlowMaster)

Peak Flow Depth

(from FlowMaster)

Is Permanent Channel

Protection Required?

Is Permanent Channel

Protection Provided?

2-Year Storm: 6.70 cfs 6.70 fps 2.9 in. Yes Yes (ACB Matting)

10-Year Storm: 16.51 cfs 7.85 fps 4.8 in. Yes Yes (ACB Matting)

100-Year Storm: 38.37 cfs 10.13 fps 7.7 in. Yes Yes (ACB Matting)

IV. Western Swale Hydraulic Analysis Summary

Bottom Width: 4.0 feet Velocities in red indicate computed flow velocities that exceed 3 fps (which is the maximum velocity where permanent erosion protection is not required)

Average Side Slope (H:V): 3H:1V

Average Longitudinal Slope: 12.70%

Peak Flow

(from Hydraflow)

Peak Flow Velocity

(from FlowMaster)

Peak Flow Depth

(from FlowMaster)

Is Permanent Channel

Protection Required?

Is Permanent Channel

Protection Provided?

2-Year Storm: 8.85 cfs 6.37 fps 3.4 in. Yes Yes (ACB Matting)

10-Year Storm: 18.66 cfs 8.09 fps 5.2 in. Yes Yes (ACB Matting)

100-Year Storm: 38.90 cfs 10.09 fps 7.8 in. Yes Yes (ACB Matting)

V. Parking Lot Swale 1 Hydraulic Analysis Summary

Bottom Width: 4.0 feet Velocities in red indicate computed flow velocities that exceed 3 fps (which is the maximum velocity where permanent erosion protection is not required)

Average Side Slope (H:V): 2H:1V

Average Longitudinal Slope: 33.00%

Peak Flow

(from Hydraflow)

Peak Flow Velocity

(from FlowMaster)

Peak Flow Depth

(from FlowMaster)

Is Permanent Channel

Protection Required?

Is Permanent Channel

Protection Provided?

2-Year Storm: 0.71 cfs 3.51 fps 0.6 in. Yes Yes (ACB Matting)

10-Year Storm: 1.69 cfs 4.92 fps 1.0 in. Yes Yes (ACB Matting)

100-Year Storm: 3.81 cfs 6.65 fps 1.6 in. Yes Yes (ACB Matting)

Williamsburg, VA - April 2023

VI. Parking Lot Swale 2 Hydraulic Analysis Summary

Bottom Width: 4.0 feet Velocities in red indicate computed flow velocities that exceed 3 fps (which is the maximum velocity where permanent erosion protection is not required)

Average Side Slope (H:V): 2H:1V

Average Longitudinal Slope: 33.00%

Peak Flow

(from Hydraflow)

Peak Flow Velocity

(from FlowMaster)

Peak Flow Depth

(from FlowMaster)

Is Permanent Channel

Protection Required?

Is Permanent Channel

Protection Provided?

2-Year Storm: 0.13 cfs 1.80 fps 0.2 in. No Yes (ACB Matting)

10-Year Storm: 0.21 cfs 2.19 fps 0.3 in. No Yes (ACB Matting)

100-Year Storm: 0.37 cfs 2.72 fps 0.4 in. No Yes (ACB Matting)

SUPPORTING HYDROLOGIC ANALYSIS COMPUTATIONS

(USING HYDRAFLOW HYDROGRAPHS AND NOAA ATLAS 14

PRECIPITATION DATA)

Hydraflow Table of Contents COLO Hydrographs.gpw

Hydraflow Hydrographs Extension for Autodesk® Civil 3D® 2019 by Autodesk, Inc. v2019.2 Monday, 05 / 15 / 2023

Watershed Model Schematic

2 - Year Summary Report Hydrograph Reports

Hydrograph No. 1, SCS Runoff, Eastern Swale Subwatershed TR-55 Tc Worksheet

Hydrograph No. 2, SCS Runoff, Western Swale Subwatershed TR-55 Tc Worksheet

Hydrograph No. 3, SCS Runoff, Parking Lot Subwatershed Swale 1 Hydrograph No. 4, SCS Runoff, Parking Lot Subwatershed Swale 2 Hydrograph No. 5, Reservoir, Eastern Dissipator

Pond Report - Eastern Swale Dissipator Hydrograph No. 6, Reservoir, Western Dissipator

Pond Report - Western Swale Dissipator

10 - Year Summary Report Hydrograph Reports

Hydrograph No. 1, SCS Runoff, Eastern Swale Subwatershed Hydrograph No. 2, SCS Runoff, Western Swale Subwatershed Hydrograph No. 3, SCS Runoff, Parking Lot Subwatershed Swale 1 Hydrograph No. 4, SCS Runoff, Parking Lot Subwatershed Swale 2 Hydrograph No. 5, Reservoir, Eastern Dissipator Hydrograph No. 6, Reservoir, Western Dissipator

25 - Year Summary Report Hydrograph Reports

Hydrograph No. 1, SCS Runoff, Eastern Swale Subwatershed Hydrograph No. 2, SCS Runoff, Western Swale Subwatershed Hydrograph No. 3, SCS Runoff, Parking Lot Subwatershed Swale 1 Hydrograph No. 4, SCS Runoff, Parking Lot Subwatershed Swale 2 Hydrograph No. 5, Reservoir, Eastern Dissipator Hydrograph No. 6, Reservoir, Western Dissipator

100 - Year Summary Report Hydrograph Reports

Hydrograph No. 1, SCS Runoff, Eastern Swale Subwatershed Hydrograph No. 2, SCS Runoff, Western Swale Subwatershed Hydrograph No. 3, SCS Runoff, Parking Lot Subwatershed Swale 1 Hydrograph No. 4, SCS Runoff, Parking Lot Subwatershed Swale 2 Hydrograph No. 5, Reservoir, Eastern Dissipator Hydrograph No. 6, Reservoir, Western Dissipator

IDF Report

1 2 3 4

Watershed Model Schematic Hydraflow Hydrographs Extension for Autodesk® Civil 3D® 2019 by Autodesk, Inc. v2019.2

Project: COLO Hydrographs.gpw Monday, 05 / 15 / 2023

Hyd. Origin Description

Legend

1 SCS Runoff Eastern Swale Subwatershed

2 SCS Runoff Western Swale Subwatershed

3 SCS Runoff Parking Lot Subwatershed Swale 1

4 SCS Runoff Parking Lot Subwatershed Swale 2

5 Reservoir Eastern Dissipator

6 Reservoir Western Dissipator

Hydrograph Summary Report

Hyd. Hydrograph Peak Time Time to Hyd. Inflow Maximum Total Hydrograph

No. type flow interval Peak volume hyd(s) elevation strge used Description

(origin) (cfs) (min) (min) (cuft) (ft) (cuft)

1 SCS Runoff 6.701 1 756 47,491 ------ ------ ------ Eastern Swale Subwatershed

2 SCS Runoff 8.854 1 745 50,700 ------ ------ ------ Western Swale Subwatershed

3 SCS Runoff 0.708 1 725 2,306 ------ ------ ------ Parking Lot Subwatershed Swale 1

4 SCS Runoff 0.126 1 724 400 ------ ------ ------ Parking Lot Subwatershed Swale 2

5 Reservoir 6.701 1 756 47,023 1 4.22 563 Eastern Dissipator

6 Reservoir 8.853 1 746 50,233 2 27.21 559 Western Dissipator

COLO Hydrographs.gpw Return Period: 2 Year Monday, 05 / 15 / 2023

Hydraflow Hydrographs Extension for Autodesk® Civil 3D® 2019 by Autodesk, Inc. v2019.2

Hydrograph Report

Hydraflow Hydrographs Extension for Autodesk® Civil 3D® 2019 by Autodesk, Inc. v2019.2 Monday, 05 / 15 / 2023

Hyd. No. 1

Eastern Swale Subwatershed

Hydrograph type = SCS Runoff Peak discharge = 6.701 cfs Storm frequency = 2 yrs Time to peak = 12.60 hrs Time interval = 1 min Hyd. volume = 47,491 cuft Drainage area = 12.320 ac Curve number = 70.1 Basin Slope = 0.0 % Hydraulic length = 0 ft Tc method = TR55 Time of conc. (Tc) = 47.40 min Total precip. = 3.57 in Distribution = Type III Storm duration = 24 hrs Shape factor = 484

0 2 4 6 8 10 12 14 16 18 20 22 24 26

Q (cfs)

0.00 0.00

1.00 1.00

2.00 2.00

3.00 3.00

4.00 4.00

5.00 5.00

6.00 6.00

7.00 7.00

Q (cfs)

Time (hrs)

Eastern Swale Subwatershed

Hyd. No. 1 -- 2 Year

Hyd No. 1

TR55 Tc Worksheet

Hydraflow Hydrographs Extension for Autodesk® Civil 3D® 2019 by Autodesk, Inc. v2019.2

Hyd. No. 1

Eastern Swale Subwatershed

Description A B C Totals

Sheet Flow Manning's n-value = 0.400 0.011 0.011 Flow length (ft) = 50.0 0.0 0.0 Two-year 24-hr precip. (in) = 3.23 0.00 0.00 Land slope (%) = 0.33 0.00 0.00

Travel Time (min) = 25.24 + 0.00 + 0.00 = 25.24

Shallow Concentrated Flow Flow length (ft) = 565.00 2087.00 0.00 Watercourse slope (%) = 0.33 2.20 0.00 Surface description = Unpaved Paved Unpaved Average velocity (ft/s) =0.93 3.02 0.00

Travel Time (min) = 10.16 + 11.54 + 0.00 = 21.70

Channel Flow X sectional flow area (sqft) = 6.00 0.00 0.00 Wetted perimeter (ft) = 20.83 0.00 0.00 Channel slope (%) = 13.00 0.00 0.00 Manning's n-value = 0.032 0.015 0.015 Velocity (ft/s) =7.29

0.00 0.00

Flow length (ft) ({0})225.0 0.0 0.0

Travel Time (min) = 0.51 + 0.00 + 0.00 = 0.51

Total Travel Time, Tc .............................................................................. 47.40 min

Hydraflow Hydrographs Extension for Autodesk® Civil 3D® 2019 by Autodesk, Inc. v2019.2 Monday, 05 / 15 / 2023

Hyd. No. 2

Western Swale Subwatershed

Hydrograph type = SCS Runoff Peak discharge = 8.854 cfs Storm frequency = 2 yrs Time to peak = 12.42 hrs Time interval = 1 min Hyd. volume = 50,700 cuft Drainage area = 9.420 ac Curve number = 77 Basin Slope = 0.0 % Hydraulic length = 0 ft Tc method = TR55 Time of conc. (Tc) = 33.90 min Total precip. = 3.57 in Distribution = Type III Storm duration = 24 hrs Shape factor = 484

0 2 4 6 8 10 12 14 16 18 20 22 24 26

Q (cfs)

0.00 0.00

2.00 2.00

4.00 4.00

6.00 6.00

8.00 8.00

10.00 10.00

Q (cfs)

Time (hrs)

Western Swale Subwatershed

Hyd. No. 2 -- 2 Year

Hyd No. 2

TR55 Tc Worksheet

Hydraflow Hydrographs Extension for Autodesk® Civil 3D® 2019 by Autodesk, Inc. v2019.2

Hyd. No. 2

Western Swale Subwatershed

Description A B C Totals

Sheet Flow Manning's n-value = 0.400 0.011 0.011 Flow length (ft) = 50.0 0.0 0.0 Two-year 24-hr precip. (in) = 3.23 0.00 0.00 Land slope (%) = 1.50 0.00 0.00

Travel Time (min) = 13.77 + 0.00 + 0.00 = 13.77

Shallow Concentrated Flow Flow length (ft) = 350.00 2557.00 0.00 Watercourse slope (%) = 0.69 1.85 0.00 Surface description = Unpaved Paved Unpaved Average velocity (ft/s) =1.34 2.76 0.00

Travel Time (min) = 4.35 + 15.41 + 0.00 = 19.77

Channel Flow X sectional flow area (sqft) = 7.00 0.00 0.00 Wetted perimeter (ft) = 21.50 0.00 0.00 Channel slope (%) = 8.33 0.00 0.00 Manning's n-value = 0.032 0.015 0.015 Velocity (ft/s) =6.34

0.00 0.00

Flow length (ft) ({0})156.0 0.0 0.0

Travel Time (min) = 0.41 + 0.00 + 0.00 = 0.41

Total Travel Time, Tc .............................................................................. 33.90 min

Hydraflow Hydrographs Extension for Autodesk® Civil 3D® 2019 by Autodesk, Inc. v2019.2 Monday, 05 / 15 / 2023

Hyd. No. 3

Parking Lot Subwatershed Swale 1

Hydrograph type = SCS Runoff Peak discharge = 0.708 cfs Storm frequency = 2 yrs Time to peak = 12.08 hrs Time interval = 1 min Hyd. volume = 2,306 cuft Drainage area = 0.550 ac Curve number = 71.2 Basin Slope = 0.0 % Hydraulic length = 0 ft Tc method = User Time of conc. (Tc) = 6.00 min Total precip. = 3.57 in Distribution = Type III Storm duration = 24 hrs Shape factor = 484

0 2 4 6 8 10 12 14 16 18 20 22 24 26

Q (cfs)

0.00 0.00

0.10 0.10

0.20 0.20

0.30 0.30

0.40 0.40

0.50 0.50

0.60 0.60

0.70 0.70

0.80 0.80

0.90 0.90

1.00 1.00

Q (cfs)

Time (hrs)

Parking Lot Subwatershed Swale 1

Hyd. No. 3 -- 2 Year

Hyd No. 3

Hydraflow Hydrographs Extension for Autodesk® Civil 3D® 2019 by Autodesk, Inc. v2019.2 Monday, 05 / 15 / 2023

Hyd. No. 4

Parking Lot Subwatershed Swale 2

Hydrograph type = SCS Runoff Peak discharge = 0.126 cfs Storm frequency = 2 yrs Time to peak = 12.07 hrs Time interval = 1 min Hyd. volume = 400 cuft Drainage area = 0.040 ac Curve number = 91.7 Basin Slope = 0.0 % Hydraulic length = 0 ft Tc method = User Time of conc. (Tc) = 6.00 min Total precip. = 3.57 in Distribution = Type III Storm duration = 24 hrs Shape factor = 484

0 2 4 6 8 10 12 14 16 18 20 22 24

Q (cfs)

0.00 0.00

0.05 0.05

0.10 0.10

0.15 0.15

0.20 0.20

0.25 0.25

0.30 0.30

0.35 0.35

0.40 0.40

0.45 0.45

0.50 0.50

Q (cfs)

Time (hrs)

Parking Lot Subwatershed Swale 2

Hyd. No. 4 -- 2 Year

Hyd No. 4

Hydraflow Hydrographs Extension for Autodesk® Civil 3D® 2019 by Autodesk, Inc. v2019.2 Monday, 05 / 15 / 2023

Hyd. No. 5

Eastern Dissipator

Hydrograph type = Reservoir Peak discharge = 6.701 cfs Storm frequency = 2 yrs Time to peak = 12.60 hrs Time interval = 1 min Hyd. volume = 47,023 cuft Inflow hyd. No. = 1 - Eastern Swale SubwatershedMax. Elevation = 4.22 ft Reservoir name = Eastern Swale Dissipator Max. Storage = 563 cuft

Storage Indication method used.

0 2 4 6 8 10 12 14 16 18 20 22 24 26

Q (cfs)

0.00 0.00

1.00 1.00

2.00 2.00

3.00 3.00

4.00 4.00

5.00 5.00

6.00 6.00

7.00 7.00

Q (cfs)

Time (hrs)

Eastern Dissipator

Hyd. No. 5 -- 2 Year

Hyd No. 5 Hyd No. 1 Total storage used = 563 cuft

Pond Report 10

Hydraflow Hydrographs Extension for Autodesk® Civil 3D® 2019 by Autodesk, Inc. v2019.2 Monday, 05 / 15 / 2023

Pond No. 1 - Eastern Swale Dissipator

Pond Data

Contours -User-defined contour areas. Conic method used for volume calculation. Begining Elevation = 2.00 ft

Stage / Storage Table

Stage (ft) Elevation (ft) Contour area (sqft) Incr. Storage (cuft) Total storage (cuft)

0.00 2.00 126 0 0

1.00 3.00 230 175 175

2.00 4.00 360 293 468

3.00 5.00 514 435 903

Culvert / Orifice Structures Weir Structures

[A] [B] [C] [PrfRsr] [A] [B] [C] [D]

Rise (in) = 0.00 0.00 0.00 0.00

Span (in) = 0.00 0.00 0.00 0.00

No. Barrels = 0 0 0 0

Invert El. (ft) = 0.00 0.00 0.00 0.00

Length (ft) = 0.00 0.00 0.00 0.00

Slope (%) = 0.00 0.00 0.00 n/a

N-Value = .013 .013 .013 n/a

Orifice Coeff. = 0.60 0.60 0.60 0.60

Multi-Stage = n/a No No No

Crest Len (ft) = 25.00 0.00 0.00 0.00

Crest El. (ft) = 4.00 0.00 0.00 0.00

Weir Coeff. = 2.60 3.33 3.33 3.33

Weir Type = Broad --- --- ---

Multi-Stage = No No No No

Exfil.(in/hr) = 0.000 (by Wet area)

TW Elev. (ft) = 0.00

Note: Culvert/Orifice outflows are analyzed under inlet (ic) and outlet (oc) control. Weir risers checked for orifice conditions (ic) and submergence (s).

Stage / Storage / Discharge Table

Stage Storage Elevation Clv A Clv B Clv C PrfRsr Wr A Wr B Wr C Wr D Exfil User Total ft cuft ft cfs cfs cfs cfs cfs cfs cfs cfs cfs cfs cfs

0.00 0 2.00 --- --- --- --- 0.00 --- --- --- --- --- 0.000

1.00 175 3.00 --- --- --- --- 0.00 --- --- --- --- --- 0.000

2.00 468 4.00 --- --- --- --- 0.00 --- --- --- --- --- 0.000

3.00 903 5.00 --- --- --- --- 65.00 --- --- --- --- --- 65.00

Hydraflow Hydrographs Extension for Autodesk® Civil 3D® 2019 by Autodesk, Inc. v2019.2 Monday, 05 / 15 / 2023

Hyd. No. 6

Western Dissipator

Hydrograph type = Reservoir Peak discharge = 8.853 cfs Storm frequency = 2 yrs Time to peak = 12.43 hrs Time interval = 1 min Hyd. volume = 50,233 cuft Inflow hyd. No. = 2 - Western Swale SubwatershedMax. Elevation = 27.21 ft Reservoir name = Western Swale Dissipator Max. Storage = 559 cuft

Storage Indication method used.

0 2 4 6 8 10 12 14 16 18 20 22 24 26

Q (cfs)

0.00 0.00

2.00 2.00

4.00 4.00

6.00 6.00

8.00 8.00

10.00 10.00

Q (cfs)

Time (hrs)

Western Dissipator

Hyd. No. 6 -- 2 Year

Hyd No. 6 Hyd No. 2 Total storage used = 559 cuft

Pond Report 12

Hydraflow Hydrographs Extension for Autodesk® Civil 3D® 2019 by Autodesk, Inc. v2019.2 Monday, 05 / 15 / 2023

Pond No. 2 - Western Swale Dissipator

Pond Data

Contours -User-defined contour areas. Conic method used for volume calculation. Begining Elevation = 25.00 ft

Stage / Storage Table

Stage (ft) Elevation (ft) Contour area (sqft) Incr. Storage (cuft) Total storage (cuft)

0.00 25.00 126 0 0

1.00 26.00 230 175 175

2.00 27.00 360 293 468

3.00 28.00 514 435 903

Culvert / Orifice Structures Weir Structures

[A] [B] [C] [PrfRsr] [A] [B] [C] [D]

Rise (in) = 0.00 0.00 0.00 0.00

Span (in) = 0.00 0.00 0.00 0.00

No. Barrels = 0 0 0 0

Invert El. (ft) = 0.00 0.00 0.00 0.00

Length (ft) = 0.00 0.00 0.00 0.00

Slope (%) = 0.00 0.00 0.00 n/a

N-Value = .013 .013 .013 n/a

Orifice Coeff. = 0.60 0.60 0.60 0.60

Multi-Stage = n/a No No No

Crest Len (ft) = 35.00 0.00 0.00 0.00

Crest El. (ft) = 27.00 0.00 0.00 0.00

Weir Coeff. = 2.60 3.33 3.33 3.33

Weir Type = Broad --- --- ---

Multi-Stage = No No No No

Exfil.(in/hr) = 0.000 (by Wet area)

TW Elev. (ft) = 0.00

Note: Culvert/Orifice outflows are analyzed under inlet (ic) and outlet (oc) control. Weir risers checked for orifice conditions (ic) and submergence (s).

Stage / Storage / Discharge Table

Stage Storage Elevation Clv A Clv B Clv C PrfRsr Wr A Wr B Wr C Wr D Exfil User Total ft cuft ft cfs cfs cfs cfs cfs cfs cfs cfs cfs cfs cfs

0.00 0 25.00 --- --- --- --- 0.00 --- --- --- --- --- 0.000

1.00 175 26.00 --- --- --- --- 0.00 --- --- --- --- --- 0.000

2.00 468 27.00 --- --- --- --- 0.00 --- --- --- --- --- 0.000

3.00 903 28.00 --- --- --- --- 91.00 --- --- --- --- --- 91.00

Hyd. Hydrograph Peak Time Time to Hyd. Inflow Maximum Total Hydrograph

No. type flow interval Peak volume hyd(s) elevation strge used Description

(origin) (cfs) (min) (min) (cuft) (ft) (cuft)

1 SCS Runoff 16.51 1 753 109,535 ------ ------ ------ Eastern Swale Subwatershed

2 SCS Runoff 18.66 1 744 104,759 ------ ------ ------ Western Swale Subwatershed

3 SCS Runoff 1.686 1 725 5,219 ------ ------ ------ Parking Lot Subwatershed Swale 1

4 SCS Runoff 0.209 1 724 684 ------ ------ ------ Parking Lot Subwatershed Swale 2

5 Reservoir 16.51 1 753 109,067 1 4.40 642 Eastern Dissipator

6 Reservoir 18.66 1 744 104,291 2 27.35 618 Western Dissipator

COLO Hydrographs.gpw Return Period: 10 Year Monday, 05 / 15 / 2023

Hydraflow Hydrographs Extension for Autodesk® Civil 3D® 2019 by Autodesk, Inc. v2019.2 Monday, 05 / 15 / 2023

Hyd. No. 1

Eastern Swale Subwatershed

Hydrograph type = SCS Runoff Peak discharge = 16.51 cfs Storm frequency = 10 yrs Time to peak = 12.55 hrs Time interval = 1 min Hyd. volume = 109,535 cuft Drainage area = 12.320 ac Curve number = 70.1 Basin Slope = 0.0 % Hydraulic length = 0 ft Tc method = TR55 Time of conc. (Tc) = 47.40 min Total precip. = 5.52 in Distribution = Type III Storm duration = 24 hrs Shape factor = 484

0 2 4 6 8 10 12 14 16 18 20 22 24 26

Q (cfs)

0.00 0.00

3.00 3.00

6.00 6.00

9.00 9.00

12.00 12.00

15.00 15.00

18.00 18.00

Q (cfs)

Time (hrs)

Eastern Swale Subwatershed

Hyd. No. 1 -- 10 Year

Hydraflow Hydrographs Extension for Autodesk® Civil 3D® 2019 by Autodesk, Inc. v2019.2 Monday, 05 / 15 / 2023

Hyd. No. 2

Western Swale Subwatershed

Hydrograph type = SCS Runoff Peak discharge = 18.66 cfs Storm frequency = 10 yrs Time to peak = 12.40 hrs Time interval = 1 min Hyd. volume = 104,759 cuft Drainage area = 9.420 ac Curve number = 77 Basin Slope = 0.0 % Hydraulic length = 0 ft Tc method = TR55 Time of conc. (Tc) = 33.90 min Total precip. = 5.52 in Distribution = Type III Storm duration = 24 hrs Shape factor = 484

0 2 4 6 8 10 12 14 16 18 20 22 24 26

Q (cfs)

0.00 0.00

3.00 3.00

6.00 6.00

9.00 9.00

12.00 12.00

15.00 15.00

18.00 18.00

21.00 21.00

Q (cfs)

Time (hrs)

Western Swale Subwatershed

Hyd. No. 2 -- 10 Year

Hydraflow Hydrographs Extension for Autodesk® Civil 3D® 2019 by Autodesk, Inc. v2019.2 Monday, 05 / 15 / 2023

Hyd. No. 3

Parking Lot Subwatershed Swale 1

Hydrograph type = SCS Runoff Peak discharge = 1.686 cfs Storm frequency = 10 yrs Time to peak = 12.08 hrs Time interval = 1 min Hyd. volume = 5,219 cuft Drainage area = 0.550 ac Curve number = 71.2 Basin Slope = 0.0 % Hydraulic length = 0 ft Tc method = User Time of conc. (Tc) = 6.00 min Total precip. = 5.52 in Distribution = Type III Storm duration = 24 hrs Shape factor = 484

0 2 4 6 8 10 12 14 16 18 20 22 24 26

Q (cfs)

0.00 0.00

1.00 1.00

2.00 2.00

Q (cfs)

Time (hrs)

Parking Lot Subwatershed Swale 1

Hyd. No. 3 -- 10 Year

Hydraflow Hydrographs Extension for Autodesk® Civil 3D® 2019 by Autodesk, Inc. v2019.2 Monday, 05 / 15 / 2023

Hyd. No. 4

Parking Lot Subwatershed Swale 2

Hydrograph type = SCS Runoff Peak discharge = 0.209 cfs Storm frequency = 10 yrs Time to peak = 12.07 hrs Time interval = 1 min Hyd. volume = 684 cuft Drainage area = 0.040 ac Curve number = 91.7 Basin Slope = 0.0 % Hydraulic length = 0 ft Tc method = User Time of conc. (Tc) = 6.00 min Total precip. = 5.52 in Distribution = Type III Storm duration = 24 hrs Shape factor = 484

0 2 4 6 8 10 12 14 16 18 20 22 24

Q (cfs)

0.00 0.00

0.05 0.05

0.10 0.10

0.15 0.15

0.20 0.20

0.25 0.25

0.30 0.30

0.35 0.35

0.40 0.40

0.45 0.45

0.50 0.50

Q (cfs)

Time (hrs)

Parking Lot Subwatershed Swale 2

Hyd. No. 4 -- 10 Year

Hydraflow Hydrographs Extension for Autodesk® Civil 3D® 2019 by Autodesk, Inc. v2019.2 Monday, 05 / 15 / 2023

Hyd. No. 5

Eastern Dissipator

Hydrograph type = Reservoir Peak discharge = 16.51 cfs Storm frequency = 10 yrs Time to peak = 12.55 hrs Time interval = 1 min Hyd. volume = 109,067 cuft Inflow hyd. No. = 1 - Eastern Swale SubwatershedMax. Elevation = 4.40 ft Reservoir name = Eastern Swale Dissipator Max. Storage = 642 cuft

Storage Indication method used.

0 2 4 6 8 10 12 14 16 18 20 22 24 26

Q (cfs)

0.00 0.00

3.00 3.00

6.00 6.00

9.00 9.00

12.00 12.00

15.00 15.00

18.00 18.00

Q (cfs)

Time (hrs)

Eastern Dissipator

Hyd. No. 5 -- 10 Year

Hyd No. 5 Hyd No. 1 Total storage used = 642 cuft

Hydraflow Hydrographs Extension for Autodesk® Civil 3D® 2019 by Autodesk, Inc. v2019.2 Monday, 05 / 15 / 2023

Hyd. No. 6

Western Dissipator

Hydrograph type = Reservoir Peak discharge = 18.66 cfs Storm frequency = 10 yrs Time to peak = 12.40 hrs Time interval = 1 min Hyd. volume = 104,291 cuft Inflow hyd. No. = 2 - Western Swale SubwatershedMax. Elevation = 27.35 ft Reservoir name = Western Swale Dissipator Max. Storage = 618 cuft

Storage Indication method used.

0 2 4 6 8 10 12 14 16 18 20 22 24 26

Q (cfs)

0.00 0.00

3.00 3.00

6.00 6.00

9.00 9.00

12.00 12.00

15.00 15.00

18.00 18.00

21.00 21.00

Q (cfs)

Time (hrs)

Western Dissipator

Hyd. No. 6 -- 10 Year

Hyd No. 6 Hyd No. 2 Total storage used = 618 cuft

Hyd. Hydrograph Peak Time Time to Hyd. Inflow Maximum Total Hydrograph

No. type flow interval Peak volume hyd(s) elevation strge used Description

(origin) (cfs) (min) (min) (cuft) (ft) (cuft)

1 SCS Runoff 23.93 1 752 157,051 ------ ------ ------ Eastern Swale Subwatershed

2 SCS Runoff 25.69 1 744 144,379 ------ ------ ------ Western Swale Subwatershed

3 SCS Runoff 2.413 1 725 7,432 ------ ------ ------ Parking Lot Subwatershed Swale 1

4 SCS Runoff 0.265 1 724 878 ------ ------ ------ Parking Lot Subwatershed Swale 2

5 Reservoir 23.93 1 752 156,583 1 4.51 691 Eastern Dissipator

6 Reservoir 25.69 1 744 143,911 2 27.43 655 Western Dissipator

COLO Hydrographs.gpw Return Period: 25 Year Monday, 05 / 15 / 2023

Hydraflow Hydrographs Extension for Autodesk® Civil 3D® 2019 by Autodesk, Inc. v2019.2 Monday, 05 / 15 / 2023

Hyd. No. 1

Eastern Swale Subwatershed

Hydrograph type = SCS Runoff Peak discharge = 23.93 cfs Storm frequency = 25 yrs Time to peak = 12.53 hrs Time interval = 1 min Hyd. volume = 157,051 cuft Drainage area = 12.320 ac Curve number = 70.1 Basin Slope = 0.0 % Hydraulic length = 0 ft Tc method = TR55 Time of conc. (Tc) = 47.40 min Total precip. = 6.84 in Distribution = Type III Storm duration = 24 hrs Shape factor = 484

0 2 4 6 8 10 12 14 16 18 20 22 24 26

Q (cfs)

0.00 0.00

4.00 4.00

8.00 8.00

12.00 12.00

16.00 16.00

20.00 20.00

24.00 24.00

Q (cfs)

Time (hrs)

Eastern Swale Subwatershed

Hyd. No. 1 -- 25 Year

Hydraflow Hydrographs Extension for Autodesk® Civil 3D® 2019 by Autodesk, Inc. v2019.2 Monday, 05 / 15 / 2023

Hyd. No. 2

Western Swale Subwatershed

Hydrograph type = SCS Runoff Peak discharge = 25.69 cfs Storm frequency = 25 yrs Time to peak = 12.40 hrs Time interval = 1 min Hyd. volume = 144,379 cuft Drainage area = 9.420 ac Curve number = 77 Basin Slope = 0.0 % Hydraulic length = 0 ft Tc method = TR55 Time of conc. (Tc) = 33.90 min Total precip. = 6.84 in Distribution = Type III Storm duration = 24 hrs Shape factor = 484

0 2 4 6 8 10 12 14 16 18 20 22 24 26

Q (cfs)

0.00 0.00

4.00 4.00

8.00 8.00

12.00 12.00

16.00 16.00

20.00 20.00

24.00 24.00

28.00 28.00

Q (cfs)

Time (hrs)

Western Swale Subwatershed

Hyd. No. 2 -- 25 Year

Hydraflow Hydrographs Extension for Autodesk® Civil 3D® 2019 by Autodesk, Inc. v2019.2 Monday, 05 / 15 / 2023

Hyd. No. 3

Parking Lot Subwatershed Swale 1

Hydrograph type = SCS Runoff Peak discharge = 2.413 cfs Storm frequency = 25 yrs Time to peak = 12.08 hrs Time interval = 1 min Hyd. volume = 7,432 cuft Drainage area = 0.550 ac Curve number = 71.2 Basin Slope = 0.0 % Hydraulic length = 0 ft Tc method = User Time of conc. (Tc) = 6.00 min Total precip. = 6.84 in Distribution = Type III Storm duration = 24 hrs Shape factor = 484

0 2 4 6 8 10 12 14 16 18 20 22 24 26

Q (cfs)

0.00 0.00

1.00 1.00

2.00 2.00

3.00 3.00

Q (cfs)

Time (hrs)

Parking Lot Subwatershed Swale 1

Hyd. No. 3 -- 25 Year

Hydraflow Hydrographs Extension for Autodesk® Civil 3D® 2019 by Autodesk, Inc. v2019.2 Monday, 05 / 15 / 2023

Hyd. No. 4

Parking Lot Subwatershed Swale 2

Hydrograph type = SCS Runoff Peak discharge = 0.265 cfs Storm frequency = 25 yrs Time to peak = 12.07 hrs Time interval = 1 min Hyd. volume = 878 cuft Drainage area = 0.040 ac Curve number = 91.7 Basin Slope = 0.0 % Hydraulic length = 0 ft Tc method = User Time of conc. (Tc) = 6.00 min Total precip. = 6.84 in Distribution = Type III Storm duration = 24 hrs Shape factor = 484

0 2 4 6 8 10 12 14 16 18 20 22 24

Q (cfs)

0.00 0.00

0.05 0.05

0.10 0.10

0.15 0.15

0.20 0.20

0.25 0.25

0.30 0.30

0.35 0.35

0.40 0.40

0.45 0.45

0.50 0.50

Q (cfs)

Time (hrs)

Parking Lot Subwatershed Swale 2

Hyd. No. 4 -- 25 Year

Hydraflow Hydrographs Extension for Autodesk® Civil 3D® 2019 by Autodesk, Inc. v2019.2 Monday, 05 / 15 / 2023

Hyd. No. 5

Eastern Dissipator

Hydrograph type = Reservoir Peak discharge = 23.93 cfs Storm frequency = 25 yrs Time to peak = 12.53 hrs Time interval = 1 min Hyd. volume = 156,583 cuft Inflow hyd. No. = 1 - Eastern Swale SubwatershedMax. Elevation = 4.51 ft Reservoir name = Eastern Swale Dissipator Max. Storage = 691 cuft

Storage Indication method used.

0 2 4 6 8 10 12 14 16 18 20 22 24 26

Q (cfs)

0.00 0.00

4.00 4.00

8.00 8.00

12.00 12.00

16.00 16.00

20.00 20.00

24.00 24.00

Q (cfs)

Time (hrs)

Eastern Dissipator

Hyd. No. 5 -- 25 Year

Hyd No. 5 Hyd No. 1 Total storage used = 691 cuft

Hydraflow Hydrographs Extension for Autodesk® Civil 3D® 2019 by Autodesk, Inc. v2019.2 Monday, 05 / 15 / 2023

Hyd. No. 6

Western Dissipator

Hydrograph type = Reservoir Peak discharge = 25.69 cfs Storm frequency = 25 yrs Time to peak = 12.40 hrs Time interval = 1 min Hyd. volume = 143,911 cuft Inflow hyd. No. = 2 - Western Swale SubwatershedMax. Elevation = 27.43 ft Reservoir name = Western Swale Dissipator Max. Storage = 655 cuft

Storage Indication method used.

0 2 4 6 8 10 12 14 16 18 20 22 24 26

Q (cfs)

0.00 0.00

4.00 4.00

8.00 8.00

12.00 12.00

16.00 16.00

20.00 20.00

24.00 24.00

28.00 28.00

Q (cfs)

Time (hrs)

Western Dissipator

Hyd. No. 6 -- 25 Year

Hyd No. 6 Hyd No. 2 Total storage used = 655 cuft

Hyd. Hydrograph Peak Time Time to Hyd. Inflow Maximum Total Hydrograph

No. type flow interval Peak volume hyd(s) elevation strge used Description

(origin) (cfs) (min) (min) (cuft) (ft) (cuft)

1 SCS Runoff 38.37 1 752 250,936 ------ ------ ------ Eastern Swale Subwatershed

2 SCS Runoff 38.91 1 743 220,583 ------ ------ ------ Western Swale Subwatershed

3 SCS Runoff 3.807 1 725 11,786 ------ ------ ------ Parking Lot Subwatershed Swale 1

4 SCS Runoff 0.366 1 724 1,238 ------ ------ ------ Parking Lot Subwatershed Swale 2

5 Reservoir 38.37 1 752 250,468 1 4.70 774 Eastern Dissipator

6 Reservoir 38.90 1 743 220,115 2 27.57 714 Western Dissipator

COLO Hydrographs.gpw Return Period: 100 Year Monday, 05 / 15 / 2023

Hydraflow Hydrographs Extension for Autodesk® Civil 3D® 2019 by Autodesk, Inc. v2019.2 Monday, 05 / 15 / 2023

Hyd. No. 1

Eastern Swale Subwatershed

Hydrograph type = SCS Runoff Peak discharge = 38.37 cfs Storm frequency = 100 yrs Time to peak = 12.53 hrs Time interval = 1 min Hyd. volume = 250,936 cuft Drainage area = 12.320 ac Curve number = 70.1 Basin Slope = 0.0 % Hydraulic length = 0 ft Tc method = TR55 Time of conc. (Tc) = 47.40 min Total precip. = 9.27 in Distribution = Type III Storm duration = 24 hrs Shape factor = 484

0 2 4 6 8 10 12 14 16 18 20 22 24 26

Q (cfs)

0.00 0.00

10.00 10.00

20.00 20.00

30.00 30.00

40.00 40.00

Q (cfs)

Time (hrs)

Eastern Swale Subwatershed

Hyd. No. 1 -- 100 Year

Hydraflow Hydrographs Extension for Autodesk® Civil 3D® 2019 by Autodesk, Inc. v2019.2 Monday, 05 / 15 / 2023

Hyd. No. 2

Western Swale Subwatershed

Hydrograph type = SCS Runoff Peak discharge = 38.91 cfs Storm frequency = 100 yrs Time to peak = 12.38 hrs Time interval = 1 min Hyd. volume = 220,583 cuft Drainage area = 9.420 ac Curve number = 77 Basin Slope = 0.0 % Hydraulic length = 0 ft Tc method = TR55 Time of conc. (Tc) = 33.90 min Total precip. = 9.27 in Distribution = Type III Storm duration = 24 hrs Shape factor = 484

0 2 4 6 8 10 12 14 16 18 20 22 24 26

Q (cfs)

0.00 0.00

10.00 10.00

20.00 20.00

30.00 30.00

40.00 40.00

Q (cfs)

Time (hrs)

Western Swale Subwatershed

Hyd. No. 2 -- 100 Year

Hydraflow Hydrographs Extension for Autodesk® Civil 3D® 2019 by Autodesk, Inc. v2019.2 Monday, 05 / 15 / 2023

Hyd. No. 3

Parking Lot Subwatershed Swale 1

Hydrograph type = SCS Runoff Peak discharge = 3.807 cfs Storm frequency = 100 yrs Time to peak = 12.08 hrs Time interval = 1 min Hyd. volume = 11,786 cuft Drainage area = 0.550 ac Curve number = 71.2 Basin Slope = 0.0 % Hydraulic length = 0 ft Tc method = User Time of conc. (Tc) = 6.00 min Total precip. = 9.27 in Distribution = Type III Storm duration = 24 hrs Shape factor = 484

0 2 4 6 8 10 12 14 16 18 20 22 24 26

Q (cfs)

0.00 0.00

1.00 1.00

2.00 2.00

3.00 3.00

4.00 4.00

Q (cfs)

Time (hrs)

Parking Lot Subwatershed Swale 1

Hyd. No. 3 -- 100 Year

Hydraflow Hydrographs Extension for Autodesk® Civil 3D® 2019 by Autodesk, Inc. v2019.2 Monday, 05 / 15 / 2023

Hyd. No. 4

Parking Lot Subwatershed Swale 2

Hydrograph type = SCS Runoff Peak discharge = 0.366 cfs Storm frequency = 100 yrs Time to peak = 12.07 hrs Time interval = 1 min Hyd. volume = 1,238 cuft Drainage area = 0.040 ac Curve number = 91.7 Basin Slope = 0.0 % Hydraulic length = 0 ft Tc method = User Time of conc. (Tc) = 6.00 min Total precip. = 9.27 in Distribution = Type III Storm duration = 24 hrs Shape factor = 484

0 2 4 6 8 10 12 14 16 18 20 22 24

Q (cfs)

0.00 0.00

0.05 0.05

0.10 0.10

0.15 0.15

0.20 0.20

0.25 0.25

0.30 0.30

0.35 0.35

0.40 0.40

0.45 0.45

0.50 0.50

Q (cfs)

Time (hrs)

Parking Lot Subwatershed Swale 2

Hyd. No. 4 -- 100 Year

Hydraflow Hydrographs Extension for Autodesk® Civil 3D® 2019 by Autodesk, Inc. v2019.2 Monday, 05 / 15 / 2023

Hyd. No. 5

Eastern Dissipator

Hydrograph type = Reservoir Peak discharge = 38.37 cfs Storm frequency = 100 yrs Time to peak = 12.53 hrs Time interval = 1 min Hyd. volume = 250,468 cuft Inflow hyd. No. = 1 - Eastern Swale SubwatershedMax. Elevation = 4.70 ft Reservoir name = Eastern Swale Dissipator Max. Storage = 774 cuft

Storage Indication method used.

0 2 4 6 8 10 12 14 16 18 20 22 24 26

Q (cfs)

0.00 0.00

10.00 10.00

20.00 20.00

30.00 30.00

40.00 40.00

Q (cfs)

Time (hrs)

Eastern Dissipator

Hyd. No. 5 -- 100 Year

Hyd No. 5 Hyd No. 1 Total storage used = 774 cuft

Hydraflow Hydrographs Extension for Autodesk® Civil 3D® 2019 by Autodesk, Inc. v2019.2 Monday, 05 / 15 / 2023

Hyd. No. 6

Western Dissipator

Hydrograph type = Reservoir Peak discharge = 38.90 cfs Storm frequency = 100 yrs Time to peak = 12.38 hrs Time interval = 1 min Hyd. volume = 220,115 cuft Inflow hyd. No. = 2 - Western Swale SubwatershedMax. Elevation = 27.57 ft Reservoir name = Western Swale Dissipator Max. Storage = 714 cuft

Storage Indication method used.

0 2 4 6 8 10 12 14 16 18 20 22 24 26

Q (cfs)

0.00 0.00

10.00 10.00

20.00 20.00

30.00 30.00

40.00 40.00

Q (cfs)

Time (hrs)

Western Dissipator

Hyd. No. 6 -- 100 Year

Hyd No. 6 Hyd No. 2 Total storage used = 714 cuft

Hydraflow Rainfall Report

Hydraflow Hydrographs Extension for Autodesk® Civil 3D® 2019 by Autodesk, Inc. v2019.2 Monday, 05 / 15 / 2023

Return Intensity-Duration-Frequency Equation Coefficients (FHA) Period

(Yrs) B D E (N/A)

1 0.0000 0.0000 0.0000 --------

2 71.8477 13.3000 0.8718 --------

3 0.0000 0.0000 0.0000 --------

5 75.7517 14.2000 0.8271 --------

10 54.7382 10.8000 0.8016 --------

25 103.3028 16.6000 0.8227 --------

50 116.5747 17.3000 0.8234 --------

100 124.5731 17.6000 0.8144 --------

File name: SampleFHA.idf

Intensity = B / (Tc + D)^E

Return Intensity Values (in/hr) Period

(Yrs) 5 min 10 15 20 25 30 35 40 45 50 55 60

1 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00

2 5.70 4.62 3.90 3.38 2.99 2.69 2.45 2.24 2.08 1.93 1.81 1.70

3 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00

5 6.58 5.43 4.65 4.08 3.64 3.30 3.02 2.79 2.59 2.42 2.28 2.15

10 5.99 4.81 4.04 3.51 3.11 2.80 2.55 2.35 2.18 2.03 1.91 1.80

25 8.25 6.95 6.03 5.34 4.81 4.38 4.03 3.73 3.48 3.26 3.08 2.91

50 9.05 7.66 6.67 5.92 5.34 4.87 4.48 4.16 3.88 3.64 3.43 3.25

100 9.83 8.35 7.30 6.49 5.87 5.36 4.94 4.59 4.29 4.03 3.80 3.60

Tc = time in minutes. Values may exceed 60.

Rainfall Precipitation Table (in)

Precip. file name: Sample.pcp

Storm Distribution 1-yr 2-yr 3-yr 5-yr 10-yr 25-yr 50-yr 100-yr

SCS 24-hour 1.20 3.57 0.00 4.62 5.52 6.84 8.00 9.27

SCS 6-Hr 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00

Huff-1st 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00

Huff-2nd 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00

Huff-3rd 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00

Huff-4th 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00

Huff-Indy 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00

Custom 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00

Precipitation Values Obtained from NOAA Atlas 14 on following page

*+,-./012+3456+789, **+,-./012+:4;4

<�=�>�<?&@=<=>�>=���A?&B�&�@C�&�>=D�>&�

;E7E+F-GGHGI+JE+78/KHGI+FE+LHGI+ME+N8/OPQ-RI+7ES1RK8I+8GT+JE+5HU1P

VWXXI+V8KH-G8U+Y18KZ1/+41/[H01I+4HU[1/+49/HG\I+78/PU8GT

N]̂K8Q.U8/+_+N]̂\/89ZH08U+_+789,̂`̂81/H8U,

<A����

<a�$������b�����b����b��������)��c ���d�����������e��f�"gh����)������������'����i������f��j� a ������������'���id����j

� � k �g �k kg �gg �gg kgg �ggg k$��� g gk lmEnoopmEqrst g !g lmEqnqpmErnqt g kkk lmErmspmEouvt g %�% lmErorpmEowxt g �g� lmEonrpmExvrt g ��� lmEowmpmEvrvt g !� lmExqnpmEwsvt g !"� lmExwupmEwwqt g "�g lmEvrspuEmvt � g lmEwmspuEuot

�g$��� g % % lmErvrpmExsst g �%� lmEowqpmEvrqt g !!"

lmEvmrpmEwwmt � gg lmEwmnpuEust luEmupuEsrt luEumpuEnxt luEuvpuEqxt luEsrpuErvt � k� luEnrpuExut luEqspuEvst

�k$��� g !g!

lmExnupmEwmnt g "%k lmEvxnpuEmxt luEmspuEsrt luEuqpuEqut luEsvpuErwt � k% luEnwpuExnt luEqwpuEvot luErvpuEwwt luExmpsEurt � gk luExvpsEswt

�g$��� luEmmpuEsqt luEsupuEqvt � %g luEqrpuExvt luEoopsEmqt luEwmpsEnrt lsEumpsEomt � k� lsEswpsEvrt lsEqopnEumt � g� lsExmpnEqnt lsEvwpnExmt

%g$��� luEsrpuErqt luErupuEvot � gk luEvrpsEsvt lsEurpsEoot lsErnpnEunt lsEvqpnErnt � k� lnEurpnEwnt � "g lnEqopqEnqt lnEvxpqEwst lqEssprEqut

�$f� luErmpuEvqt � g� luEvspsEsst � kg lsEsxpsExxt lsEovpnEsvt � k� lnEsupnEwqt g" lnEoopqErut lqEuuprEumt k �g lqErwprExnt k "" lrEsqpoEost lrEvmpxEnvt

�$f� luEompuEwvt luEwqpsEnwt lsEqspsEwwt lsEvwpnErxt lnEqxpqEnut lnEwwpqEwxt k �� lqErnprEoxt k !� lrEumpoEqnt lrEvwpxErst loErvpvEqwt

%$f� luEwnpsEqut � k!

lsEnnpsEwmt lsEwupnEoqt lnEqopqEnqt lqEsmprEswt k " lqEvrpoEunt % �g lrErspxEmst loEsqpvEmmt ! k lxEsrpwEqnt " k" lvEuspumExt

��$f� � kk lsEsrpsEwxt � g� lsExmpnErxt lnEqmpqErmt lqEmxprEnwt k �� lqEwxpoEont lrExvpxExqt loEonpvEwqt lxErrpumEnt �g % lvEvqpusEst lwEwwpuqEmt

� $f� lsEoxpnEsvt � k� lnEsrpnEwwt lqEsmprEuxt k k� lqEwvpoEuxt loEuqpxEort ! gg lxEuspvEwqt lvEuxpumEqt �g � lwEnspuuEwt luuEmpuqEnt lusEqpuoEqt

�$��d lnEmxpnEvvt �k lnExspqExut k �k lqExwpoEmrt lrEowpxEsut lxEmupvEwrt lvEunpumEqt �g !

lwEnrpusEut lumExpuqEut lusEopuoEwt luqEnpuwErt

�$��d lnEsrpqEmwt lnEwqpqEwot k %� lrEmrpoEnot lrEwopxErnt lxEnmpwEsxt " k% lvEqnpumEvt �� g lwEoqpusEqt luuEmpuqEnt �k � lusEwpuxEst luqEopuwEvt

$��d lnEqnpqEnmt lqEuoprEsst k "g lrEnmpoEoot loEsnpxEvrt ! k� lxErwpwErwt lvExspuuEut lwEwspusExt �� g luuEnpuqEot �k k lunEspuxErt luqEwpsmEmt

�$��d lqEmopqEwxt k �!

lqEvwprEwwt loEurpxErnt lxEuvpvEvut lvEorpumExt �� g lwEvopusEst luuEupunEwt lusErpurEvt luqEqpuvEot luoEmpsmEwt

�g$��d k �g lqEovprEost lrEoupoExqt � %g loEwrpvEnxt lvEmnpwEowt �g % lwErwpuuEot �� g lumEvpunEst lusEspuqEwt �k � lunErpuoEvt lurErpuwErt luxEmpsuEvt

�g$��d loEqupxErmt lxEoqpvEwst lwEsrpumEvt lumErpusEqt lusEqpuqEot �k � lunEvpuoEnt lurEnpuvEst luoEvpsmEst luvEwpsnEmt lsmErpsrEqt

�g$��d ! k lxEwvpwEsmt �g � lwEqvpumEwt luuEnpunEut lusEvpuqEvt �k " luqEvpuxEut luoEqpuwEmt luxEwpsmEwt luwErpssEwt lsuEopsrEot �k � lsnEupsxEvt k$��d �g % lwEwwpuuEqt luuEvpunEqt luqEmpuoEmt lurExpuvEmt luvEupsmExt �� k luwEwpssEwt lsuExpsrEst �k � lsnEopsxErt lsoEupnmEvt �� g lsxEwpnnEqt

%g$��d lusEmpunErt �k g luqEupuoEmt luoErpuvExt luvEqpsmEvt lsmEwpsnExt lssEvpsoEmt �% k lsqEopsvEst �! k lsoEqpnmEqt lsvEvpnnErt lnmErpnrEwt u+N/10H9HK8KH-G+y/1z.1G0P+lN]t+1,KH{8K1,+HG+KZH,+K8QU1+8/1+Q8,1T+-G+y/1z.1G0P+8G8UP,H,+-y+98/KH8U+T./8KH-G+,1/H1,+lNJ4tE

V.{Q1/,+HG+98/1GKZ1,H,+8/1+N]+1,KH{8K1,+8K+U-|1/+8GT+.991/+Q-.GT,+-y+KZ1+wm}+0-GyHT1G01+HGK1/[8UE+MZ1+9/-Q8QHUHKP+KZ8K+9/10H9HK8KH-G+y/1z.1G0P+1,KH{8K1, ly-/+8+\H[1G+T./8KH-G+8GT+8[1/8\1+/10.//1G01+HGK1/[8Ut+|HUU+Q1+\/18K1/+KZ8G+KZ1+.991/+Q-.GT+l-/+U1,,+KZ8G+KZ1+U-|1/+Q-.GTt+H,+r}E+3,KH{8K1,+8K+.991/+Q-.GT, 8/1+G-K+0Z10R1T+8\8HG,K+9/-Q8QU1+{8~H{.{+9/10H9HK8KH-G+lN7Nt+1,KH{8K1,+8GT+{8P+Q1+ZH\Z1/+KZ8G+0.//1GKUP+[8UHT+N7N+[8U.1,E

NU18,1+/1y1/+K-+VWXX+XKU8,+uq+T-0.{1GK+y-/+{-/1+HGy-/{8KH-GE

F80R+K-+M-9

<A����bf����