Conservation Commission Agenda (linked)

REGED
FEB 2 4 2026
Planning & Development
Town of Waterford, CT
RECEED
FEB 2 4 7026
Planning & Development
Town of Waterford, CT

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Drainage Area Map
M Bichabitats
Mamacoke Brook Outfall
C_j Watersheds [| ‘arcels
October, 2025
Channel Stabilization
and Restoration
USGS Contours (1-ft)
New London, CT x Point of Analysis
Document Path: M:\GIS\GIS\PROJECTS\25201.01 Connecticut College Mamacoke Stream Restoration\Maps\Analysis\MamacokeStream_Hydro.aprx

Marsh + Salt Pond DA
Side Swale eg 4 mn
Marsh Salt Pond
Mamacoke Stream DA
Reach VEN Routing Diagram for Mamacoke Stream_Existing Cond
Prepared by Biohabitats, Inc., Printed 10/1/2025
HydroCAD® 10.00-25 s/n 05603 © 2019 HydroCAD Software Solutions LLC

0.562 39 >75% Grass cover, Good, HSG A (3)
3.056 61 >75% Grass cover, Good, HSG B (1)
1.802 74 >75% Grass cover, Good, HSG C (1)
0.081 80 >75% Grass cover, Good, HSG D (1)
0.303 96 Gravel surface, HSG A (3)
1.539 30 Meadow, non-grazed, HSG A (3)
0.540 58 Meadow, non-grazed, HSG B (1, 2, 3)
0.321 71 Meadow, non-grazed, HSG C (1)
3.117 78 Meadow, non-grazed, HSG D (1, 2, 3)
0.177 98 Paved parking, HSG A (3)
4.374 98 Paved parking, HSG B (1, 2)
4.627 98 Paved parking, HSG C (1)
0.095 98 Paved parking, HSG D (1)
0.024 98 Water Surface, HSG A (3)
0.000 98 Water Surface, HSG B (3)
1.581 98 Water Surface, HSG D (3)
1.976 36 Woods, Fair, HSG A (3)
31.543 60 Woods, Fair, HSG B (1, 2, 3)
11.266 73 Woods, Fair, HSG C (1)
9.038 79 Woods, Fair, HSG D (1, 2, 3)
0.094 43 Woods/grass comb., Fair, HSG A (3)
0.369 65 Woods/grass comb., Fair, HSG B (1)
0.112 76 Woods/grass comb., Fair, HSG C (1)
0.050 82 Woods/grass comb., Fair, HSG D (3)
76.644 70 TOTAL AREA

4.673 HSGA 3
39.882 HSG B 1,2,3
18.128 HSG C i
13.960 HSG D 1,2,3
0.000 Other
76.644 TOTAL AREA

0.562 3.056 1.802 0.081 0.000 5.501 >75% Grass cover, Good 1,3
0.303 0.000 0.000 0.000 0.000 0.303 Gravel surface 3
1,539 0.540 0.321 3.117 0.000 5.517 Meadow, non-grazed 1,2,3
0.177 4.374 4,627 0.095 0.000 9.273 Paved parking 1,2,3
0.024 0.000 0.000 1.581 0.000 1.605 Water Surface 3
1.976 31,543 11.266 9.038 0.000 53.822 Woods, Fair 1,2,3
0.094 0.369 0.142 0.050 0.000 0.624 Woods/grass comb., Fair 1,3
4.673 39.882 18.128 13.960 0.000 76.644 TOTAL AREA

1°41 0.00 0.00 80.0 0.0375 0.013 18.0 0.0 0.0
2 1 0.00 0.00 41.0 0.0455 0.013 24.0 0.0 0.0
3°64 0.00 0.00 24.0 0.0417 0.013 15.0 0.0 0.0
4 1 0.00 0.00 218.0 0.0417 0.013 24.0 0.0 0.0
5 1 0.00 0.00 65.0 0.1846 0.013 24.0 0.0 0.0
6 5P 0.40 -0.13 46.0 0.0115 0.035 36.0 36.0 12.0

1 Project Rainfall events imported from "NRCS-Rain.txt" for 810 CT New London

Flow Length=2,868' Tc=34.6 min CN=73 Runoff=21.95 cfs 3.509 af
Subcatchment2: Side Swale DA Runoff Area=478,640 sf 0.23% Impervious Runoff Depth=0.32"
Flow Length=1,369' Tc=31.5 min CN=61 Runoff=1.17 cfs 0.297 af
Subcatehment3: Marsh + SaltPondDA Runoff Area=539,972 sf 14.37% Impervious Runoff Depth=0.29"
Flow Length=1,347' Tc=39.9 min CN=60 Runoff=1.02 cfs 0.304 af
Total Runoff Area = 76.644 ac Runoff Volume = 4.110 af Average Runoff Depth = 0.64”
85.81% Pervious = 65.767 ac 14.19% Impervious = 10.877 ac

f
y
,
,
g
,
p
,
NOAA 24-hr D 1-Year Rainfall=2.89"
Area (sf) CN __ Description
1,173 79 Woods, Fair, HSG D
589 58 Meadow, non-grazed, HSG B
13,985 71 Meadow, non-grazed, HSG C
92,123 78 Meadow, non-grazed, HSG D
189,429 98 Paved parking, HSG B
201,565 98 Paved parking, HSG C
4,122 98 Paved parking, HSG D
749,434 60 Woods, Fair, HSG B
490,744 73 Woods, Fair, HSG C
340,738 79 Woods, Fair, HSG D
133,138 61 >75% Grass cover, Good, HSG B
78,490 74 »>75% Grass cover, Good, HSG C
3,510 80 >75% Grass cover, Good, HSG D
16,079 65 Woods/grass comb., Fair, HSG B
4,883 76 ___Woods/grass comb., Fair, HSG C
2,320,002 73 Weighted Average
1,924,886 82.97% Pervious Area
395,116 17.03% Impervious Area

Grassed Waterway Kv= 15.0 fps
2.1 268 0.0112 2.15 Shallow Concentrated Flow, Shallow - Paved
Paved Kv= 20.3 fps
0.6 92 0.0326 2.71 Shallow Concentrated Flow, Shallow - Grass
Grassed Waterway Kv= 15.0 fps
4.1 433 0.1247 1.77 Shallow Concentrated Flow, Shallow - Woods
Woodland Kv= 5.0 fps
0.7 179 0.0503 4.55 Shallow Concentrated Flow, Shallow - Paved
Paved Kv= 20.3 fps
0.1 80 0.0375 11.51 20.34 Pipe Channel, RCP_Round 18"
18.0" Round Area= 1.8 sf Perim=4.7' r= 0.38
n= 0.013 Concrete pipe, bends & connections
0.0 11 0.0455 15.36 48.26 Pipe Channel, RCP_Round 24”
24.0" Round Area= 3.1 sf Perim= 6.3' r= 0.50'
n= 0.013 Concrete pipe, bends & connections
0.0 24 0.0417 10.75 13.19 Pipe Channel, RCP_Round 15”
15.0" Round Area= 1.2 sf Perim= 3.9 r= 0.31'
n= 0.013 Concrete pipe, bends & connections
0.2 218 0.0417 14.70 46.20 Pipe Channel, RCP_Round 24"
24.0" Round Area= 3.1 sf Perim= 6.3' r= 0.50"
n= 0.013 Concrete pipe, bends & connections
0.0 65 0.1846 30.94 97.20 Pipe Channel, RCP_Round 24"
24.0" Round Area= 3.1 sf Perim= 6.3' r= 0.50'
n= 0.013 Concrete pipe, bends & connections
4.7 §21 0.1373 1.85 Shallow Concentrated Flow, Shallow - Woods
Woodland Kv= 5.0 fps
0.9 804 0.0672 14.35 574.16 Trap/Vee/Rect Channel Flow, Channef to POI
Bot.W=4.00' D=4.00' Z= 1.5‘ Top.W=16.00°
n= 0.045
34.6 2,868 Total

a4 pane eeies NOAA 24-hr D
a cca: | ns jaar ae 1-Year Rainfall=2.89" _
oo es Runoff Area=2, 320, 002 sf
a crop ~. Runoff Volume=3.509 af
bet to _ Runoff Depth=0.79"
Tc=34.6 min
__CN=73
Flow (cfs)
0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34 36 38 40 42 44 46 48
Time (hours)

Runoff by SCS TR 20 met od,
,
g
,
p
NOAA 24-hrD 1-Year Rainfall=2.89"
Area (sf) CN Description
18,188 58 Meadow, non-grazed, HSG B
7,974 78 Meadow, non-grazed, HSG D
1,093 98 Paved parking, HSG B
441,497 60 Woods, Fair, HSGB
9,888 79 Woods, Fair, HSG D
478,640 61 Weighted Average
477,547 99.77% Pervious Area
1,093 0.23% Impervious Area
Te Length Slope Velocity Capacity Description
(min) _(feet) (ft/ft}__ (ft/sec) (cfs)
27.3 4100 0.0400 0.06 Sheet Flow, Sheet
Woods: Dense underbrush n= 0.800 P2= 3.45"
3.8 1,183 0.1175 5.14 Shallow Concentrated Flow, Shallow - Grass
Grassed Waterway Kv= 15.0 fps
0.4 86 0.0174 3.46 27.64 Trap/Vee/Rect Channel Flow, Channel to POI
Bot.W=5.00' D=1.00' Z= 3.0 '/ Top.W=11.00'
n= 0.045
31.5 1,369 Total

NOAA 24-hr D
a 1-Year Rainfall=2.89"
Runoff Area=478,640 sf
Runoff Volume=0.297 af
2): Runoff Depth=0.32"
° Flow Length=1,369'
Tc=31.5 min
CN=61
0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34 36 38 40 42 44 46 48
Time (hours)

Runoff by SCS TR 20 method, UH SCS, Weighted C ,
p
,
NOAA 24-hr D 1-Year Rainfall=2.89"
Area (sf) CN Description
13,188 96 Gravel surface, HSG A
814 98 Water Surface, HSG D
2 36 Woods, Fair, HSG A
3,713 79 Woods, Fair, HSG D
67,020 30 Meadow, non-grazed, HSG A
4,743 58 Meadow, non-grazed, HSG B
35,684 78 Meadow, non-grazed, HSG D
181 98 Water Surface, HSG D
7,704 98 Paved parking, HSGA
86,051 36 Woods, Fair, HSG A
183,080 60 Woods, Fair, HSG B
38,165 79 Woods, Fair, HSG D
9,120 98 Water Surface, HSG D
24,475 39 >75% Grass cover, Good, HSG A
906 98 Water Surface, HSG A
1 98 Water Surface, HSG B
4 98 Water Surface, HSG D
57,141 98 Water Surface, HSG D
4,075 43 Woods/grass comb., Fair, HSG A
2,165 82 Woods/grass comb., Fair, HSG D
140 98 Water Surface, HSGA
17 98 Water Surface, HSG D
1,586 98 Water Surface, HSG D
539,972 60 Weighted Average
462,361 85.63% Pervious Area
77,611 14.37% Impervious Area
Te Length Slope Velocity Capacity Description
(min) _ (feet) (ft/ft) _ (ft/sec) (cfs)
27.3 100 0.0400 0.06 Sheet Flow, Sheet - Woods
Woods: Dense underbrush n= 0.800 P2= 3.45"
2.5 226 0.0885 1.49 Shallow Concentrated Flow, Shallow - Woods
Woodland Kv= 5.0 fps
14 197 0.0406 3.02 Shallow Concentrated Flow, Shallow - Grassed
Grassed Waterway Kv= 15.0 fps
8.2 332 0.0181 0.67 Shallow Concentrated Flow, Shallow - Woods
Woodland Kv= 5.0 fps
0.8 492 9.83 Lake or Reservoir, Pond
Mean Depth= 3.00'
39.9 1,347 Total

‘ Tite - NOAA 24-hr D
1-Year Rainfall=2.89"
Runoff Area=539,972 sf
Runoff Volume=0.304 af
: Runoff Depth=0.29"
° Flow Length=1,347'
Tc=39.9 min
CN=60
0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34 36 38 40 42 44 46 48
Time (hours)

Flow Length=2,868' Tc=34.6 min CN=73 Runoff=33.37 cfs 5.087 af
Subcatchment2: Side Swale DA Runoff Area=478,640 sf 0.23% Impervious Runoff Depth=0.55"
Flow Length=1,369' Tc=31.5 min CN=61 Runoff=2.60 cfs 0.504 af
Subcatchment3: Marsh+ Salt Pond DA Runoff Area=539,972 sf 14.37% Impervious Runoff Depth=0.51"
Flow Length=1,347' Tc=39.9 min CN=60 Runoff=2.31 cfs 0.527 af
Total Runoff Area = 76.644 ac Runoff Volume = 6.118 af Average Runoff Depth = 0.96”
85.81% Pervious = 65.767 ac 14.19% Impervious = 10.877 ac

f
y
od, UH SCS, Weighted CN, Time Span  0.00 48.00 hrs, dt  0.05 hrs
NOAA 24-hr D 2-Year Rainfall=3.45"
Area (sf) CN __ Description
1,173 79 Woods, Fair, HSG D
589 58 Meadow, non-grazed, HSG B
13,985 71. Meadow, non-grazed, HSG C
92,123 78 Meadow, non-grazed, HSG D
189,429 98 Paved parking, HSG B
201,565 98 Paved parking, HSGC
4,122 98 Paved parking, HSG D
749,434 60 Woods, Fair, HSGB
490,744 73 Woods, Fair, HSGC
340,738 79 Woods, Fair, HSG D
133,138 61 »>75% Grass cover, Good, HSG B
78,490 74 >75% Grass cover, Good, HSG C
3,510 80 >75% Grass cover, Good, HSG D
16,079 65 Woods/grass comb., Fair, HSG B
4,883 76 Woods/grass comb., Fair, HSG C
2,320,002 73 Weighted Average
1,924,886 82.97% Pervious Area
395,116 17.03% Impervious Area

Grassed Waterway Kv= 15.0 fps
21 268 0.0112 2.15 Shallow Concentrated Flow, Shallow - Paved
Paved Kv= 20.3 fps
0.6 92 0.0326 2.71 Shallow Concentrated Flow, Shallow - Grass
Grassed Waterway Kv= 15.0 fps
41 433 0.1247 1.77 Shallow Concentrated Flow, Shallow - Woods
Woodland Kv= 5.0 fps
0.7 179 0.0503 4.55 Shallow Concentrated Flow, Shallow - Paved
Paved Kv= 20.3 fps
0.1 80 0.0375 11.51 20.34 Pipe Channel, RCP_Round 18"
18.0" Round Area= 1.8 sf Perim= 4.7' r= 0.38"
n= 0.013 Concrete pipe, bends & connections
0.0 11 0.0455 15.36 48.26 Pipe Channel, RCP_Round 24"
24.0" Round Area= 3.1 sf Perim=6.3' r= 0.50!
n= 0.013 Concrete pipe, bends & connections
0.0 24 0.0417 10.75 13.19 Pipe Channel, RCP_Round 15"
15.0" Round Area= 1.2 sf Perim= 3.9' r= 0.31"
n= 0.013 Concrete pipe, bends & connections
0.2 218 0.0417 14.70 46.20 Pipe Channel, RCP_Round 24"
24.0" Round Area= 3.1 sf Perim=6.3' r= 0.50"
n= 0.013 Concrete pipe, bends & connections
0.0 65 0.1846 30.94 97.20 Pipe Channel, RCP_Round 24”
24.0" Round Area= 3.1 sf Perim= 6.3' r= 0.50°
n= 0.013 Concrete pipe, bends & connections
47 521 0.1373 1.85 Shallow Concentrated Flow, Shallow - Woods
Woodland Kv= 5.0 fps
0.9 804 0.0672 14.35 574.16 Trap/Vee/Rect Channel Flow, Channel to POI
Bot.W=4.00' D=4.00' Z= 1.5’ Top. W=16.00°
n= 0.045
34.6 2,868 Total

Flow (
1--+- Runoff Volume=5.087 af
Runoff Depth=1.15"
- Flow Length=2,868'
Tc=34.6 mi
CN=73
8B 10 12 14 16 18 20 22 24 26 28 30 32 34 36 38 40 42 44 46 48
Time (hours)

Runoff by SCS TR 20 method, UH SCS, We g
,
p
,
NOAA 24-hr D 2-Year Rainfall=3.45"
Area (sf) _CN__ Description
18,188 58 Meadow, non-grazed, HSG B
7,974 78 Meadow, non-grazed, HSG D
1,093 98 Paved parking, HSG B
441,497 60 Woods, Fair, HSG B
9,888 79 Woods, Fair, HSG D
478,640 61 Weighted Average
477,547 99.77% Pervious Area
1,093 0.23% Impervious Area
Te Length Slope Velocity Capacity Description
(min) _ (feet) (fft) _ (ft/sec) (cfs)
27.3 100 0.0400 0.06 Sheet Flow, Sheet
Woods: Dense underbrush n= 0.800 P2= 3.45"
3.8 1,183 0.1175 5.14 Shallow Concentrated Flow, Shallow - Grass
Grassed Waterway Kv= 15.0 fps
0.4 86 0.0174 3.46 27.64 Trap/Vee/Rect Channel Flow, Channel to POI
Bot.W=5.00' D=1.00' Z= 3.0 '7 Top.W=11.00'
n= 0.045
31.5 1,369 Total

NOAA 24-hr D
2-Year Rainfall=3.45"
* | ; A ~ Runoff Area=478,640 sf
Runoff Volume=0.504 af
Runoff Depth=0.55"
Flow Length=1,369'
4 Tc=31.5 min
CN=61
Flow (cfs)
0 2 4 6 8 10 12 14 16 18 20 22 24 26 26 30 32 34 36 38 40 42 44 46 48
Time (hours)

Runoff by SCS TR 20 method, UH SCS, Weighted C ,
p
,
NOAA 24-hr D 2-Year Rainfall=3.45"
Area (sf) CN Description
13,188 96 Gravel surface, HSG A
814 98 Water Surface, HSG D
2 36 Woods, Fair, HSGA
3,713 79 Woods, Fair, HSGD
67,020 30 Meadow, non-grazed, HSG A
4,743 58 Meadow, non-grazed, HSG B
35,684 78 Meadow, non-grazed, HSG D
181 98 Water Surface, HSG D
7,704 98 Paved parking, HSG A
86,051 36 Woods, Fair, HSGA
183,080 60 Woods, Fair, HSG B
38,165 79 Woods, Fair, HSG D
9,120 98 Water Surface, HSG D
24,475 39 >75% Grass cover, Good, HSGA
906 98 Water Surface, HSGA
4 98 Water Surface, HSG B
1 98 Water Surface, HSG D
57,141 98 Water Surface, HSG D
4,075 43 Woods/grass comb., Fair, HSGA
2,165 82 Woods/grass comb., Fair, HSG D
140 98 Water Surface, HSGA
17 98 Water Surface, HSG D
1,586 98 Water Surface, HSG D
539,972 60 Weighted Average
462,361 85.63% Pervious Area
77,611 14.37% Impervious Area
Tc Length Slope Velocity Capacity Description
(min) _(feet) (fU/ft) _ (ft/sec) (cfs)
27.3 100 0.0400 0.06 Sheet Flow, Sheet - Woods
Woods: Dense underbrush n= 0.800 P2= 3.45"
2.5 226 0.0885 1.49 Shallow Concentrated Flow, Shallow - Woods
Woodland Kv= 5.0 fps
1.1 197 0.0406 3.02 Shallow Concentrated Flow, Shallow - Grassed
Grassed Waterway Kv= 15.0 fps
8.2 332 0.0181 0.67 Shallow Concentrated Flow, Shallow - Woods
Woodland Kv= 5.0 fos
0.8 492 9.83 Lake or Reservoir, Pond
Mean Depth= 3.00'
39.9 1,347 Total

NOAA 24-hr D
* 2-Year Rainfall=3.45"
Runoff Area=539,972 sf
Runoff Volume=0.527 af
Runoff Depth=0.51"
oo —t ton --1.. Flow Length=1,347'
Tc=39.9 min
CN=60
Flow (cfs)
0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34 36 38 40 42 44 46 48
Time (hours)

Flow Length=2,868' Tc=34.6 min CN=73 Runoff=53.89 cfs 7.948 af
Subcatchment2: Side Swale DA Runoff Area=478,640 sf 0.23% impervious Runoff Depth=1.00"
Flow Length=1,369' Tc=31.5 min CN=61 Runoff=5.69 cfs 0.918 af
Subcatchment3: Marsh + Salt PondDA Runoff Area=539,972 sf 14.37% Impervious Runoff Depth=0.95"
Flow Length=1,347' Tc=39.9 min CN=60 Runoff=5.21 cfs 0.976 af
Total Runoff Area = 76.644 ac Runoff Volume = 9.842 af Average Runoff Depth = 1.54”
85.81% Pervious = 65.767 ac 14.19% Impervious = 10.877 ac

f
y
g
,
p
,
0.05 hrs
NOAA 24-hr D 5-Year Rainfall=4.36"
Area (sf) CN Description
1,173 79 Woods, Fair, HSG D
589 58 Meadow, non-grazed, HSG B
13,985 71 Meadow, non-grazed, HSG C
92,123 78 Meadow, non-grazed, HSG D
189,429 98 Paved parking, HSG B
201,565 98 Paved parking, HSG C
4,122 98 Paved parking, HSG D
749,434 60 Woods, Fair, HSGB
490,744 73 Woods, Fair, HSGC
340,738 79 Woods, Fair, HSG D
133,138 61 >75% Grass cover, Good, HSG B
78,490 74 >75% Grass cover, Good, HSG C
3,510 80 >75% Grass cover, Good, HSG D
16,079 65 Woods/grass comb., Fair, HSG B
4,883 76 _Woods/grass comb., Fair, HSG C
2,320,002 73 Weighted Average
1,924,886 82.97% Pervious Area
395,116 17.03% Impervious Area

Grassed Waterway Kv= 15.0 fps
2.1 268 0.0112 2.15 Shallow Concentrated Flow, Shallow - Paved
Paved Kv= 20.3 fps
0.6 92 0.0326 2.71 Shallow Concentrated Flow, Shallow - Grass
Grassed Waterway Kv= 15.0 fps
4.1 433 0.1247 1.77 Shallow Concentrated Flow, Shallow - Woods
Woodland Kv= 5.0 fps
0.7 179 0.0503 4,55 Shallow Concentrated Flow, Shallow - Paved
Paved Kv= 20.3 fps
0.1 80 0.0375 11.51 20.34 Pipe Channel, RCP_Round 18”
18.0" Round Area= 1.8 sf Perim= 4.7' r= 0.38'
n= 0.013 Concrete pipe, bends & connections
0.0 11 0.0455 15.36 48.26 Pipe Channel, RCP_Round 24"
24.0" Round Area= 3.1 sf Perim=6.3' r= 0.50'
n= 0.013 Concrete pipe, bends & connections
0.0 24 0.0417 10.75 13.19 Pipe Channel, RCP_Round 15”
15.0" Round Area= 1.2 sf Perim= 3.9' r= 0.31’
n= 0.013 Concrete pipe, bends & connections
0.2 218 0.0417 14.70 46.20 Pipe Channel, RCP_Round 24"
24.0" Round Area= 3.1 sf Perim= 6.3' r= 0.50"
n= 0.013 Concrete pipe, bends & connections
0.0 65 0.1846 30.94 97.20 Pipe Channel, RCP_Round 24”
24.0" Round Area= 3.1 sf Perim= 6.3’ r= 0.50'
n= 0.013 Concrete pipe, bends & connections
47 521 0.1373 1.85 Shallow Concentrated Flow, Shallow - Woods
Woodland Kv= 5.0 fps
0.9 804 0.0672 14.35 574.16 Trap/Vee/Rect Channel Flow, Channel to POI
Bot.W=4.00' D=4.00' Z= 1.5'/' Top.W=16.00'
n= 0.045
34.6 2,868 Total

50! NOAA 24-hr D.
45; -|} -.--........ §=¥ear Rainfall=4.36"
Sr | -.--.--Runoff Area=2,320,002 sf
| Runoff Volume=7.948 af
= 30] Runoff Depth=1.79"
En! Flow Length=2,868'__
201 Tc=34.6 min
16: CN=73
10; eee ee
Se oe ee eek, Ce a
0:
8 10 12 14 16 18 20 22 24 26 28 30 32 34 36 38 40 42 44 46 48
Time (hours)
°
nD
a4
o
oo

f
y
g
NOAA 24-hr D_ 5-Year Rainfall=4.36"
Area(sf) CN Description
18,188 58 Meadow, non-grazed, HSG B
7,974 78 Meadow, non-grazed, HSG D
4,093 98 Paved parking, HSG B
441,497 60 Woods, Fair, HSGB
9888 79 Woods, Fair, HSG D
478,640 61 Weighted Average
477,547 99.77% Pervious Area
1,093 0.23% Impervious Area
Te Length Slope Velocity Capacity Description
(min) _(feet) (f/ft)__(fl/sec) (cfs)
27.3 100 0.0400 0.06 Sheet Flow, Sheet
Woods: Dense underbrush n=0.800 P2= 3.45"
3.8 1,183 0.1175 5.14 Shallow Concentrated Flow, Shallow - Grass
Grassed Waterway Kv= 15.0 fps
0.4 86 0.0174 3.46 27.64 Trap/Vee/Rect Channel Flow, Channel to PO!
Bot.W=5.00' D=1.00' Z= 3.0‘) Top.W=11.00'
n= 0.045
31.5 1,369 Total

NOAA 24-hr D
5-Year Rainfall=4.36"
Runoff Area=478,640 sf
Runoff Volume=0.918 af
i x Runoff Depth=1.00"
a Flow Length=1,369'
24 Tce=31.5 min
CN=61
0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34 36 38 40 42 44 46 48
Time (hours)

Runoff by SCS TR 20 method, UH SCS, Weighted
,
p
,
NOAA 24-hr D 5-Year Rainfall=4.36"
Area (sf) CN Description
13,188 96 Gravel surface, HSGA
814 98 Water Surface, HSG D
2 36 Woods, Fair, HSGA
3,713 79 Woods, Fair, HSGD
67,020 30 Meadow, non-grazed, HSG A
4,743. 58 Meadow, non-grazed, HSG B
35,684 78 Meadow, non-grazed, HSG D
181 98 Water Surface, HSG D
7,704 98 Paved parking, HSGA
86,051 36 Woods, Fair, HSGA
183,080 60 Woods, Fair, HSG B
38,165 79 Woods, Fair, HSGD
9,120 98 Water Surface, HSG D
24,475 39 >75% Grass cover, Good, HSGA
906 98 Water Surface, HSG A
1 98 Water Surface, HSG B
1 98 Water Surface, HSG D
57,141 98 Water Surface, HSG D
4,075 43 Woods/grass comb., Fair, HSG A
2,165 82 Woods/grass comb., Fair, HSG D
140 98 Water Surface, HSGA
17 98 Water Surface, HSG D
1,586 98 Water Surface, HSG D
539,972 60 Weighted Average
462,361 85.63% Pervious Area
77,611 14.37% Impervious Area
Te Length Slope Velocity Capacity Description
(min) _ (feet) (ft/ft) _ (ft/sec) (cfs)
27.3 100 0.0400 0.06 Sheet Flow, Sheet - Woods
Woods: Dense underbrush n= 0.800 P2= 3.45"
2.5 226 0.0885 1.49 Shallow Concentrated Flow, Shallow - Woods
Woodland Kv= 5.0 fps
1.1 197 0.0406 3.02 Shallow Concentrated Flow, Shallow - Grassed
Grassed Waterway Kv= 15.0 fps
8.2 332 0.0181 0.67 Shallow Concentrated Flow, Shallow - Woods
Woodland Kv= 5.0 fps
0.8 492 9.83 Lake or Reservoir, Pond
Mean Depth= 3.00'
39.9 1,347 Total

| an Ae ee an en a rel NOAA 24-hr D
5-Year Rainfall=4.36"
* Runoff Area=539,972 sf
z Runoff Volume=0.976 af
Sees | aaa Runoff Depth=0.95"
“4 Flow Length=1,347'
. Tc=39.9 min
; CN=60
ol !
0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34 36 38 40 42 44 46 48
Time (hours)

Flow Length=2,868' Tc=34.6 min CN=73 Runoff=72.09 cfs 10.506 af
Subcatchment2: Side Swale DA Runoff Area=478,640 sf 0.23% Impervious Runoff Depth=1.44"
Flow Length=1,369' Tc=31.5 min CN=61 Runoff=8.70 cfs 1.315 af
Subcatchment3: Marsh + SaltPondDA Runoff Area=539,972 sf. 14.37% Impervious Runoff Depth=1.37"
Flow Length=1,347' Tc=39.9 min CN=60 Runoff=8.10 cfs 1.411 af
Total Runoff Area = 76.644 ac Runoff Volume = 13.231 af Average Runoff Depth = 2.07"
85.81% Pervious = 65.767 ac 14.19% impervious = 10.877 ac

g
,
p
,
0.05 hrs
NOAA 24-hr D 10-Year Rainfall=5.11"
Area (sf) CN __ Description
1,173 79 Woods, Fair, HSG D
589 58 Meadow, non-grazed, HSG B
13,985 71 Meadow, non-grazed, HSG C
92,123 78 Meadow, non-grazed, HSG D
189,429 98 Paved parking, HSG B
201,565 98 Paved parking, HSG C
4,122 98 Paved parking, HSG D
749,434 60 Woods, Fair, HSG B
490,744 73 Woods, Fair, HSG C
340,738 79 Woods, Fair, HSG D
133,138 61 >75% Grass cover, Good, HSG B
78,490 74 >75% Grass cover, Good, HSG C
3,510 80 »>75% Grass cover, Good, HSG D
16,079 65 Woods/grass comb., Fair, HSG B
4,883 76 __Woods/grass comb.,, Fair, HSG C
2,320,002 73 Weighted Average
1,924,886 82.97% Pervious Area
395,116 17.03% Impervious Area

0.5 
(
Grassed Waterway Kv= 15.0 fps
2.1 268 0.0112 2.15 Shallow Concentrated Flow, Shallow - Paved
Paved Kv= 20.3 fps
0.6 92 0.0326 2.71 Shallow Concentrated Flow, Shallow - Grass
Grassed Waterway Kv= 15.0 fps
41 433 0.1247 1.77 Shallow Concentrated Flow, Shallow - Woods
Woodland Kv= 5.0 fps
0.7 179 0.0503 4.55 Shallow Concentrated Flow, Shallow - Paved
Paved Kv= 20.3 fps
0.1 80 0.0375 41.51 20.34 Pipe Channel, RCP_Round 18”
18.0" Round Area= 1.8 sf Perim= 4.7' r= 0.38"
n= 0.013 Concrete pipe, bends & connections
0.0 11 0.0455 15.36 48.26 Pipe Channel, RCP_Round 24”
24.0" Round Area= 3.1 sf Perim= 6.3' r= 0.50!
n= 0.013 Concrete pipe, bends & connections
0.0 24 0.0417 10.75 13.19 Pipe Channel, RCP_Round 15”
45.0" Round Area= 1.2 sf Perim= 3.9' r= 0.31'
n= 0.013 Concrete pipe, bends & connections
0.2 218 0.0417 14.70 46.20 Pipe Channel, RCP_Round 24”
24.0" Round Area= 3.1 sf Perim=6.3' r= 0.50'
n= 0.013 Concrete pipe, bends & connections
0.0 65 0.1846 30.94 97.20 Pipe Channel, RCP_Round 24”
24.0" Round Area= 3.1 sf Perim= 6.3' r= 0.50!
n= 0.013 Concrete pipe, bends & connections
4.7 521 0.1373 4.85 Shallow Concentrated Flow, Shallow - Woods
Woodland Kv= 5.0 fps
0.9 804 0.0672 14.35 574.16 Trap/Vee/Rect Channel Flow, Channel to POI
Bot.W=4.00' D=4.00' Z= 7.5 '/' Top.W=16.00'
n= 0.045
34.6 2,868 Total

Flow (cfs)
70+
65-| -
60) -
50;
455
40}
354
304
20:
15] -
104
a Flow Length=2,868'
11- Runoff Area=2,;320,002 sf
__ Runoff Volume=10.506 af
Runoff Depth=2.37"
Tc=34.6 min
Pa 8 10 12 14 16 18 20 22 24 26 28 30 32 34 36 38 40 42 44 46 48
Time (hours)

Runoff by SC
,
,
g
p
NOAA 24-hrD 10-Year Rainfall=5.11"
Area (sf) CN Description
18,188 58 Meadow, non-grazed, HSG B
7,974 78 Meadow, non-grazed, HSG D
1,093 98 Paved parking, HSG B
441,497 60 Woods, Fair, HSGB
9,888 79 Woods, Fair, HSGD
478,640 61 Weighted Average
477,547 99.77% Pervious Area
4,093 0.23% Impervious Area
Tc Length Slope Velocity Capacity Description
(min) _ (feet) (ft/ft) (ft/sec) (cfs)
27.3 100 0.0400 0.06 Sheet Flow, Sheet
Woods: Dense underbrush n= 0.800 P2= 3.45"
3.8 1,183 0.1175 5.14 Shallow Concentrated Flow, Shallow - Grass
Grassed Waterway Kv= 15.0 fps
0.4 86 0.0174 3.46 27.64 Trap/Vee/Rect Channel Flow, Channel to POI
Bot.W=5.00' D=1.00' Z= 3.0 '/ Top.W=11.00'
n= 0,045
31.5 1,369 Total

Flow (cfs)
NOAA 24-hr D
Runoff Area=478,640 sf
Runoff Volume=1.315 af
~ Flow Length=1,369'
Tce=31.5 min
a CN=61
2
4
—
6
8
10 12 14 16 18 20 22 24 26 28 30 32 34 36 38 40 42 44 46 48
Time (hours)

uf
y
,
g
p
NOAA 24-hr D 10-Year Rainfail=5.11"
Area (sf) _CN__ Description
13,188 96 Gravel surface, HSG A
814 98 Water Surface, HSG D
2 36 Woods, Fair, HSGA
3,713 79 Woods, Fair, HSG D
67,020 30 Meadow, non-grazed, HSG A
4,743 58 Meadow, non-grazed, HSG B
35,684 78 Meadow, non-grazed, HSG D .
181 98 Water Surface, HSG D
7,704 98 Paved parking, HSGA
86,051 36 Woods, Fair, HSGA
183,080 60 Woods, Fair, HSG B
38,165 79 Woods, Fair, HSG D
9,120 98 Water Surface, HSG D
24,475 39 >75% Grass cover, Good, HSG A
906 98 Water Surface, HSG A
1 98 Water Surface, HSG B
1 98 Water Surface, HSG D
57,141 98 Water Surface, HSG D
4,075 43 Woods/grass comb., Fair, HSG A
2,165 82 Woods/grass comb., Fair, HSG D
140 98 Water Surface, HSG A
17 98 Water Surface, HSG D
1,586 98 Water Surface, HSG D
539,972 60 Weighted Average
462,361 85.63% Pervious Area
77,611 14.37% Impervious Area
Te Length Slope Velocity Capacity Description
(min) (feet) _(fi/ft)__ (ft/sec) (cfs)
27.3 100 0.0400 0.06 Sheet Flow, Sheet - Woods
Woods: Dense underbrush n= 0.800 P2= 3.45"
2.5 226 0.0885 1.49 Shallow Concentrated Flow, Shallow - Woods
Woodland Kv= 5.0 fps
11 197 0.0406 3.02 Shallow Concentrated Flow, Shallow - Grassed
Grassed Waterway Kv= 15.0 fps
8.2 332 0.018% 0.67 Shallow Concentrated Flow, Shallow - Woods
Woodland Kv= 5.0 fps
0.8 492 9.83 Lake or Reservoir, Pond
Mean Depth= 3.00'
39.9 1,347 Total

7 NOAA 24-hr D
yur : ~ 40-Year Rainfall=5.11"
Sa aa a Runoff Area=539,972 sf
gs] Runoff Volume=1.411 af
z, Runoff Depth=1.37"
a Flow Length=1,347'
s “| Tc=39.9 min
2] CN=60
0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34 36 38 40 42 44 46 48
Time (hours)

Flow Length=2,868' Tc=34.6 min CN=73 Runoff=98.53 cfs 14.262 af
Subcatchment2: Side Swale DA Runoff Area=478,640 sf 0.23% Impervious Runoff Depth=2.11"
Flow Length=1,369' Tc=31.5 min CN=61 Runoff=13.37 cfs 1.929 af
Subcatchment3: Marsh+ SaltPondDA Runoff Area=539,972 sf 14.37% Impervious Runoff Depth=2.02"
Flow Length=1,347' Tc=39.9 min CN=60 Runoff=12.61 cfs 2.087 af
Total Runoff Area = 76.644 ac Runoff Volume = 18.278 af Average Runoff Depth = 2.86"
85.81% Pervious = 65.767 ac 14.19% Impervious = 10.877 ac

f
y
g
p
NOAA 24-hr D 25-Year Rainfall=6.15"
Area (sf) CN Description
1,173 79 Woods, Fair, HSG D
589 58 Meadow, non-grazed, HSG B
13,985 71 Meadow, non-grazed, HSG C
92,123 78 Meadow, non-grazed, HSG D
189,429 98 Paved parking, HSG B
201,565 98 Paved parking, HSGC
4,122 98 Paved parking, HSG D
749,434 60 Woods, Fair, HSG B
490,744 73 Woods, Fair, HSG C
340,738 79 Woods, Fair, HSG D
133,138 61 >75% Grass cover, Good, HSG B
78,490 74 »>75% Grass cover, Good, HSG C
3,510 80 »>75% Grass cover, Good, HSG D
16,079 65 Woods/grass comb., Fair, HSG B
4,883 76 __Woods/grass comb., Fair, HSG C
2,320,002 73 Weighted Average
1,924,886 82.97% Pervious Area
395,116 17.03% Impervious Area

Grassed Waterway Kv= 15.0 fps
2.1 268 0.0112 2.15 Shallow Concentrated Flow, Shallow - Paved
Paved Kv= 20.3 fps
0.6 92 0.0326 2.71 Shallow Concentrated Flow, Shallow - Grass
Grassed Waterway Kv= 15.0 fps
44 433 0.1247 1.77 Shallow Concentrated Flow, Shallow - Woods
Woodland Kv= 5.0 fps
0.7 179 0.0503 4.55 Shallow Concentrated Flow, Shallow - Paved
Paved Kv= 20.3 fps
0.1 80 0.0375 11.51 20.34 Pipe Channel, RCP_Round 18"
18.0" Round Area= 1.8 sf Perim= 4.7' r= 0.38'
n= 0.013 Concrete pipe, bends & connections
0.0 11 0.0455 16.36 48.26 Pipe Channel, RCP_Round 24”
24.0" Round Area= 3.1 sf Perim= 6.3" r= 0.50!
n= 0.013 Concrete pipe, bends & connections
0.0 24 0.0417 10.75 13.19 Pipe Channel, RCP_Round 15”
15.0" Round Area= 1.2 sf Perim=3.9' r= 0.31'
n= 0.013 Concrete pipe, bends & connections
0.2 218 0.0417 14.70 46.20 Pipe Channel, RCP_Round 24"
24.0" Round Area= 3.1 sf Perim= 6.3’ r= 0.50'
n= 0.013 Concrete pipe, bends & connections
0.0 65 0.1846 30.94 97.20 Pipe Channel, RCP_Round 24"
24.0" Round Area= 3.1 sf Perim= 6.3' r= 0.50°
n= 0.013 Concrete pipe, bends & connections
4.7 521 0.1373 1.85 Shallow Concentrated Flow, Shallow - Woods
Woodland Kv= 5.0 fps
0.9 804 0.0672 14.35 574.16 Trap/Vee/Rect Channel Flow, Channel to POI
Bot.W=4.00' D=4.00' Z= 1.5 ‘/' Top. W=16.00"
n= 0.045
34.6 2,868 Total

Flow (cfs)
954 - -
905
855]
804
755
703
653
603
554
505
454
405
354
305
255]
204
105
1§4------
- 25-Year Rainfall=6.15"
Runoff Area=2,320,002 sf
-- Runoff Volume=14.262 af
NOAA 24-hr D_
Runoff Depth=3.21"
Flow Length=2,868'
Tc=34.6 min
Time (hours)
10 12 14 16 18 20 22 24 26 28 30 32 34 36 36 40 42 44 46 48

Runoff by SCS TR 20 method, UH SCS,
g
,
p
NOAA 24-hr D 25-Year Rainfall=6.15”
Area (sf} CN Description
18,188 58 Meadow, non-grazed, HSG B
7,974 78 Meadow, non-grazed, HSG D
1,093 98 Paved parking, HSG B
441,497 60 Woods, Fair, HSGB
9,888 79 Woods, Fair, HSG D
478,640 61 Weighted Average
477,547 99.77% Pervious Area
1,093 0.23% Impervious Area
Te Length Slope Velocity Capacity Description
(min) _(feet) (ft/ft) _ (ft/sec) (cfs)
27.3 100 0.0400 0.06 Sheet Flow, Sheet
Woods: Dense underbrush n= 0.800 P2= 3.45"
3.8 1,183 0.1175 5.14 Shallow Concentrated Flow, Shallow - Grass
Grassed Waterway Kv= 15.0 fps
0.4 86 0.0174 3.46 27.64 Trap/Vee/Rect Channel Fiow, Channel to Pol
Bot.W=5.00' D=1.00' Z= 3.0 '/' Top.W=11.00"
n=.0,045
31.5 1,369 Total

ott NOAA 24-hr DL
nf --! Joo : _. 25-Year Rainfall=6.15" -
eae | co ------ Runoff Area=478,640 sf
a —___._ Runoff Volume=1.929 af
a7 a jd _.... Runoff Depth=2.11"
— + Flow Length=1,369" -
a tot _CN=61
0 2 4 6 B 10 12 14 16 18 20 22 24 26 28 30 32 34 36 38 40 42 44 46 48
Time (hours)

Runoff by SCS TR 20 method, U
,
g
,
p
NOAA 24-hr D 25-Year Rainfall=6.15"
Area (sf) CN Description
13,188 96 Gravel surface, HSG A
814 98 Water Surface, HSG D
2 36 Woods, Fair, HSGA
3,713 79 Woods, Fair, HSG D
67,020 30 Meadow, non-grazed, HSG A
4,743 58 Meadow, non-grazed, HSG B
35,684 78 Meadow, non-grazed, HSG D
181 98 Water Surface, HSG D
7,704 98 Paved parking, HSGA
86,051 36 Woods, Fair, HSGA
183,080 60 Woods, Fair, HSG B
38,165 79 Woods, Fair, HSG D
9,120 98 Water Surface, HSG D
24,475 39 >75% Grass cover, Good, HSG A
906 98 Water Surface, HSG A
1 98 Water Surface, HSG B
4 98 Water Surface, HSG D
57,141 98 Water Surface, HSG D
4,075 43 Woods/grass comb., Fair, HSG A
2,165 82 Woods/grass comb., Fair, HSG D
140 98 Water Surface, HSG A
17 98 Water Surface, HSG D
1,586 98 Water Surface, HSG D
539,972 60 Weighted Average
462,361 85.63% Pervious Area
77,611 14.37% Impervious Area
Te Length Slope Velocity Capacity Description
(min) (feet) (ft/ft)__ (ft/sec) (cfs)
27.3 100 0.0400 0.06 Sheet Flow, Sheet - Woods
Woods: Dense underbrush n= 0.800 P2= 3.45"
2.5 226 0.0885 1.49 Shallow Concentrated Flow, Shallow - Woods
Woodland Kv= 5.0 fps
11 197 0.0406 3.02 Shallow Concentrated Flow, Shallow - Grassed
Grassed Waterway Kv= 15.0 fps
8.2 332 0.018% 0.67 Shallow Concentrated Flow, Shallow - Woods
Woodland Kv= 5.0 fps
0.8 492 9.83 Lake or Reservoir, Pond
Mean Depth= 3.00'
39.9 1,347 Total

Flow (cfs)
anaes Sopa ton inns ~ NOAA 24-hr D
i: oe erenes eee - 25-Year Rainfall=6.15"
| fd Runoff Area=539,972 sf
8 Runoff Volume=2.087 af
4 —- Runoff Depth=2.02"
: ai t{ | Flow Length=1,347'
i. i _ Tc=39.9 min
ee or oo 2 1 _ CN=60
0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34 36 38 40 42 44 46 48
Time (hours)

Flow Length=2,868' Tc=34.6 min CN=73 Runoff=118.98 cis 17.199 af
Subcatchment2: Side Swale DA Runoff Area=478,640 sf 0.23% Impervious Runoff Depth=2.65"
Flow Length=1,369' Tc=31.5 min CN=61 Runoff=17.14 cfs 2.428 af
Subcatchment3: Marsh + SaltPondDA Runoff Area=539,972 sf 14.37% Impervious Runoff Depth=2.55"
Flow Length=1,347' Tc=39.9 min CN=60 Runoff=16.28 cfs 2.638 af
Total Runoff Area = 76.644 ac Runoff Volume = 22.265 af Average Runoff Depth = 3.49"
85.81% Pervious = 65.767 ac 14.19% Impervious = 10.877 ac

f
y
,
,
g
,
e Span  0.00 48.00 hrs, dt  0.05 hrs
NOAA 24-hr D 50-Year Rainfall=6.93"
Area (sf) CN Description
1,173 79 Woods, Fair, HSG D
589 58 Meadow, non-grazed, HSG B
13,985 71 Meadow, non-grazed, HSG C
92,123 78 Meadow, non-grazed, HSG D
189,429 98 Paved parking, HSGB
201,565 98 Paved parking, HSG C
4,122 98 Paved parking, HSG D
749,434 60 Woods, Fair, HSG B
490,744 73 Woods, Fair, HSG C
340,738 79 Woods, Fair, HSG D
133,138 61 >75% Grass cover, Good, HSG B
78,490 74 >75% Grass cover, Good, HSG C
3,510 80 »>75% Grass cover, Good, HSG D
16,079 65 Woods/grass comb., Fair, HSG B
4,883 76 __Woods/grass comb., Fair, HSG C
2,320,002 73 Weighted Average
1,924,886 82.97% Pervious Area
395,116 17.03% Impervious Area

Grassed Waterway Kv= 15.0 fps
2.1 268 0.0112 2.15 Shallow Concentrated Flow, Shallow - Paved
Paved Kv= 20.3 fps
0.6 92 0.0326 2.71 Shallow Concentrated Flow, Shallow - Grass
Grassed Waterway Kv= 15.0 fps
41 433 0.1247 1.77 Shallow Concentrated Flow, Shallow - Woods
Woodland Kv= 5.0 fps
0.7 179 0.0503 4.55 Shallow Concentrated Flow, Shallow - Paved
Paved Kv= 20.3 fos
0.1 80 0.0375 11.51 20.34 Pipe Channel, RCP_Round 18”
18.0" Round Area= 1.8 sf Perim=4.7' r= 0.38'
n= 0.013 Concrete pipe, bends & connections
0.0 11 0.0455 15.36 48.26 Pipe Channel, RCP_Round 24"
24.0" Round Area= 3.1 sf Perim= 6.3' r= 0.50"
n= 0.013 Concrete pipe, bends & connections
0.0 24 0.0417 10.75 43.19 Pipe Channel, RCP_Round 15"
15.0" Round Area= 1.2 sf Perim= 3.9 r= 0.31'
n= 0.013 Concrete pipe, bends & connections
0.2 218 0.0417 14.70 46.20 Pipe Channel, RCP_Round 24”
24.0" Round Area= 3.1 sf Perim= 6.3' r= 0.50"
n= 0.013 Concrete pipe, bends & connections
0.0 65 0.1846 30.94 97.20 Pipe Channel, RCP_Round 24”
24.0" Round Area= 3.1 sf Perim=6.3' r= 0.50°
n= 0.013 Concrete pipe, bends & connections
4.7 §21 0.1373 1.85 Shallow Concentrated Flow, Shallow - Woods
Woodland Kv= 5.0 fps
0.9 804 0.0672 14.35 574.16 Trap/Vee/Rect Channel Flow, Channel to POI
Bot.W=4.00' D=4.00' Z= 1.5 '' Top.W=16.00"
n= 0,045
34.6 2,868 Total

Flow (cfs)
bofotbecbecbeboch: _ NOAA 24-hr D
50-Year Rainfall=6.93"
Runoff Area=2,320,002 sf
_ Runoff Volume=17.199 af
~- Runoff Depth=3.87"
Flow Length=2,868'
be --. Tce=34.6 min
_ CN=73-
6 8 10 12 14 16 18 20 22 24 26 28 30 32 34 36 38 40 42 44 46 48
Time (hours)

f
y
g
NOAA 24-hr D 50-Year Rainfall=6.93"
Area (sf) CN Description
18,188 58 Meadow, non-grazed, HSG B
7,974 78 Meadow, non-grazed, HSG D
1,093 98 Paved parking, HSGB
441,497 60 Woods, Fair, HSG B
9,888 79 Woods, Fair, HSG D
478,640 61 Weighted Average
477,547 99.77% Pervious Area
1,093 0.23% Impervious Area
Tc Length Slope Velocity Capacity Description
(min) _(feet) (ft/ft) _ (ft/sec) (cfs)
27.3 400 0.0400 0.06 Sheet Flow, Sheet
Woods: Dense underbrush n= 0.800 P2= 3.45"
3.8 1,183 0.1175 5.14 Shallow Concentrated Flow, Shallow - Grass
Grassed Waterway Kv= 15.0 fps
0.4 86 0.0174 3.46 27.64 Trap/Vee/Rect Channel Flow, Channel to POI
Bot.W=5.00' D=1.00' Z= 3.0'/ Top.W=11.00'
n= 0.045
31.5 1,369 Total

: NOAA 24-hr D
144 . 1] 50-Year Rainfall=6.93"
ie (ere | Runoff Area=478,640 sf
ae -- a Runoff Volume=2.428 af
‘DR tei _..... Runoff Depth=2.65"
- _ i Flow Length=1,369"
o] . Tc=31.5 min
qo CN=61
0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34 36 38 40 42 44 46 48
Time (hours)

Runoff by SCS TR 20 method, UH SCS,
g
,
p
NOAA 24-hr D 50-Year Rainfall=6.93"
Area (sf) CN __ Description
13,188 96 Gravel surface, HSG A
814 98 Water Surface, HSG D
2 36 Woods, Fair, HSG A
3,713 79 Woods, Fair, HSG D
67,020 30 Meadow, non-grazed, HSG A
4,743. 58 Meadow, non-grazed, HSG B
35,684 78 Meadow, non-grazed, HSG D
181 98 Water Surface, HSG D
7,704 98 Paved parking, HSGA
86,051 36 Woods, Fair, HSGA
183,080 60 Woods, Fair, HSG B
38,165 79 Woods, Fair, HSG D
9,120 98 Water Surface, HSG D
24,475 39 >75% Grass cover, Good, HSGA
906 98 Water Surface, HSG A
41 98 Water Surface, HSG B
1 98 Water Surface, HSG D
57,141 98 Water Surface, HSG D
4,075 43 Woods/grass comb., Fair, HSG A
2,165 82 Woods/grass comb., Fair, HSG D
140 98 Water Surface, HSG A
17 98 Water Surface, HSG D
1,586 98 Water Surface, HSG D
539,972 60 Weighted Average
462,361 85.63% Pervious Area
77,611 14.37% Impervious Area
Tc Length Slope Velocity Capacity Description
(min) _ (feet) (ft/ft) _ (ft/sec) (cfs)
27.3 100 0.0400 0.06 Sheet Flow, Sheet - Woods
Woods: Dense underbrush n= 0.800 P2= 3.45"
2.5 226 0.0885 1.49 Shallow Concentrated Flow, Shallow - Woods
Woodland Kv= 5.0 fps
11 197 0.0406 3.02 Shallow Concentrated Flow, Shallow - Grassed
Grassed Waterway Kv= 15.0 fps
8.2 332 0.0181 0.67 Shallow Concentrated Flow, Shallow - Woods
Woodland Kv= 5.0 fps
0.8 492 9.83 Lake or Reservoir, Pond
Mean Depth= 3.00'
39.9 1,347 Total

Flow (cfs)
165
144
o8
CN=60
6
8 10 12 14 16 18 20 22 24 26 28 30 32 34 36 38 40 42 44 46 48
Time (hours)

Flow Length=2,868' Tc=34.6 min CN=73 Runoff=141.12 cis 20.407 af
Subcatchmentz2: Side Swale DA Runoff Area=478,640 sf 0.23% impervious Runoff Depth=3.26"
Flow Length=1,369' Tc=31.5 min CN=64 Runoff=21.35 cfs 2.988 af
Subcatchment3: Marsh+ SaltPond DA Runoff Area=539,972 sf. 14.37% Impervious Runoff Depth=3.15"
Flow Length=1,347' Tc=39.9 min CN=60 Runoff=20.41 cfs 3.259 af
Total Runoff Area = 76.644 ac Runoff Volume = 26.653 af Average Runoff Depth = 4.17”
85.81% Pervious = 65.767 ac 14.19% Impervious = 10.877 ac

NOAA 24-hr D 100-Year Rainfall=7.76"
Area (sf) CN __ Description
1,173 79 Woods, Fair, HSG D
589 58 Meadow, non-grazed, HSG B
13,985 71 Meadow, non-grazed, HSG C
92,123 78 Meadow, non-grazed, HSG D
189,429 98 Paved parking, HSG B
201,565 98 Paved parking, HSG C
4,122 98 Paved parking, HSG D
749,434 60 Woods, Fair, HSGB
490,744 73 Woods, Fair, HSG C
340,738 79 Woods, Fair, HSG D
133,138 61 >75% Grass cover, Good, HSG B
78,490 74 »>75% Grass cover, Good, HSG C
3,510 80 >75% Grass cover, Good, HSG D
16,079 65 Woods/grass comb., Fair, HSG B
4,883 76 _Woods/grass comb., Fair, HSG C
2,320,002 73 Weighted Average
1,924,886 82.97% Pervious Area
395,116 17.03% Impervious Area

Grassed Waterway Kv= 15.0 fps
2.1 268 0.0112 2.15 Shallow Concentrated Flow, Shallow - Paved
Paved Kv= 20.3 fps
0.6 92 0.0326 2.71 Shallow Concentrated Flow, Shallow - Grass
Grassed Waterway Kv= 15.0 fps
41 433 0.1247 1.77 Shallow Concentrated Flow, Shallow - Woods
Woodland Kv= 5.0 fps
0.7 179 0.0503 4,55 Shallow Concentrated Flow, Shallow - Paved
Paved Kv= 20.3 fps
0.1 80 0.0375 11.51 20.34 Pipe Channel, RCP_Round 18"
18.0" Round Area= 1.8 sf Perim= 4.7’ r= 0.38"
n= 0.013 Concrete pipe, bends & connections
0.0 11 0.0455 15.36 48.26 Pipe Channel, RCP_Round 24”
24.0" Round Area= 3.1 sf Perim=6.3' r= 0.50'
n= 0.013 Concrete pipe, bends & connections
0.0 24 0.0417 10.75 13.19 Pipe Channel, RCP_Round 15”
45.0" Round Area= 1.2 sf Perim= 3.9' r= 0.31'
n= 0.013 Concrete pipe, bends & connections
0.2 218 0.0417 14.70 46.20 Pipe Channel, RCP_Round 24”
24.0" Round Area= 3.1 sf Perim= 6.3' r= 0.50"
n= 0.013 Concrete pipe, bends & connections
0.0 65 0.1846 30.94 97.20 Pipe Channel, RCP_Round 24"
24.0" Round Area= 3.1 sf Perim= 6.3' r= 0,50"
n= 0.013 Concrete pipe, bends & connections
47 §21 0.1373 1.85 Shallow Concentrated Flow, Shallow - Woods
Woodland Kv= 5.0 fps
0.9 804 0.0672 14.35 574.16 Trap/Vee/Rect Channel Flow, Channel to POI
Bot.W=4.00' D=4.00' Z= 1.5'/) Top.W=16.00°
n= 0.045
34.6 2,868 Total

Flow (cfs)
1303
120+
110+
100;
90:
80:
70;
60;
504
40:
305
20] -
10} -
_.... NOAA 24-hr D
100-Year Rainfall=7.76"
Runoff Area=2,320,002 sf
Runoff Volume=20.407 af
Runoff. Depth=4.60"
10 12 14 16 18 20 22 24 26 28 30 32 34 36 38 40 42 44 46 48
Time (hours)

Runoff by SCS TR 20 method, U
,
g
,
p
NOAA 24-hr D 100-Year Rainfall=7.76"
Area (sf) CN Description
18,188 58 Meadow, non-grazed, HSG B
7,974 78 Meadow, non-grazed, HSG D
1,093 98 Paved parking, HSG B
441,497 60 Woods, Fair, HSGB
9,888 79 Woods, Fair, HSG D
478,640 61 Weighted Average
477,547 99.77% Pervious Area
1,093 0.23% Impervious Area
Tc Length Slope Velocity Capacity Description
(min) _(feet) (ft/ft) _ (ft/sec) (cfs)
27.3 100 0.0400 0.06 Sheet Flow, Sheet
Woods: Dense underbrush n=0.800 P2= 3.45"
3.8 1,183 0.1175 5.14 Shallow Concentrated Flow, Shallow - Grass
Grassed Waterway Kv= 15.0 fps
0.4 86 0.0174 3.46 27.64 Trap/Vee/Rect Channel Flow, Channel to POI
Bot.W=5.00' D=1.00' Z= 3.0'/) Top.W=11.00"
n= 0.045
31.5 1,369 Total

Flow (cfs)
oy ok ck ee eee BON W
SPP Nate eels tose astua
SANS APS
NOAA 24-hr D-
~-----100-Year Rainfall=7.76"
Flow Length=1,369"
i Tc=31.5 min
— CNS61~
8
10 12 14 16 18 20 22 24 26 28 30 32 34 36 38 40 42 44 46 48
Time (hours)

Runoff by SCS TR 20 method, UH SCS,
g
,
p
NOAA 24-hr D 100-Year Rainfall=7.76"
Area (sf) CN Description
13,188 96 Gravel surface, HSGA
814 98 Water Surface, HSG D
2 36 Woods, Fair, HSGA
3,713 79 Woods, Fair, HSG D
67,020 30 Meadow, non-grazed, HSG A
4,743 58 Meadow, non-grazed, HSG B
35,684 78 Meadow, non-grazed, HSG D
181 98 Water Surface, HSG D
7,704 98 Paved parking, HSGA
86,051 36 Woods, Fair, HSGA
183,080 60 Woods, Fair, HSG B
38,165 79 Woods, Fair, HSG D
9,120 98 Water Surface, HSG D
24,475 39 >75% Grass cover, Good, HSG A
906 98 Water Surface, HSG A
4 98 Water Surface, HSG B
1 98 Water Surface, HSG D
57,141 98 Water Surface, HSG D
4,075 43 Woods/grass comb., Fair, HSG A
2,165 82 Woods/grass comb., Fair, HSG D
140 98 Water Surface, HSG A
17 98 Water Surface, HSG D
1,586 98 Water Surface, HSG D
539,972 60 Weighted Average
462,361 85.63% Pervious Area
77,611 14.37% Impervious Area
Tc Length Slope Velocity Capacity Description
(min) _(feet) (ft/ft) _ (ft/sec) (cfs)
27.3 100 0.0400 0.06 Sheet Flow, Sheet - Woods
Woods: Dense underbrush n= 0.800 P2= 3.45"
2.5 226 0.0885 1.49 Shallow Concentrated Fiow, Shallow - Woods
Woodland Kv= 5.0 fps
1.1 197 0.0406 3.02 Shallow Concentrated Flow, Shallow - Grassed
Grassed Waterway Kv= 15.0 fps
8.2 332 0.0181 0.67 Shallow Concentrated Flow, Shallow - Woods
Woodland Kv= 5.0 fps
0.8 492 9.83 Lake or Reservoir, Pond
Mean Depth= 3.00'
39.9 1,347 Total

Flow (cfs)
aan)
6 8
10 12 14 16 18 20 22 24 26 28 30 32 34 36 38 40 42 44 46 48
Time (hours)


BIOHABITATS, INC.
363 Main St
Middletown, CT 06457
jwilson@biohabitats.com
Subject: Mamacoke Brook Channel Restoration
Filing #: 135296
NDDB - New Determination Number: 202508660
Expiration Date: 12/5/2027
Location Description: 435 Mohegan Ave. Parkway, Waterford, CT.
Dear Josh Wilson,
| have reviewed Natural Diversity Data Base (NDDB) maps and files regarding the proposed Mamacoke
Brook Channel Restoration project located at 435 Mohegan Ave. Parkway, Waterford, CT. Our records show
that there’s a documented occurrence of the state-listed (RCSA Sec. 26-306) Special Concern
Bolboschoenus maritimus ssp. paludosus (Bayonet Grass) plant within a part of the proposed project area
near the southwestern end of Mamacoke Pond. NDDB requires a botanical survey for this species before any
Phragmites removal or wetland restoration activities can begin in this part of the project area. NDDB does not
anticipate negative impacts to any other state-listed species within the rest of the project area outside of
Mamacoke Pond.
Botanical surveys must be done by a qualified botanist or plant ecologist at the appropriate time(s) of year to
confidently identify this state-listed plant down to the species taxonomic level.
A botanical survey report for state-listed plants should include the following elements at a minimum:
1. Survey date(s) and duration.
2. Site descriptions and photographs.
3. A description of the morphologic characters that distinguish the target State-listed plants from other
similar plants that are not State-listed.
List of component species within the survey area (including scientific binomials).
Data regarding population numbers and/or area occupied by State-listed species. The NDDB rare plant
forms must be submitted for any and all state listed species observed. *Please note that we now have
an online reporting form via the ESRI Survey123 app that we encourage people to use as an alternative
to the Word/PDF document. Both versions of the rare plant reporting forms can be found
here: Contribute Data to the NDDB (ct.gov).
as
ile. HTMT.112/5/2025 8:54:44 AMI

Plant: Bolboschoenus maritimus ssp. paludosus (Bayonet Grass)
State Protection Status: Special Concern
Habitat: Brackish intertidal high marshes, i.e., so-called "brackish meadows", areas dominated relatively low
vegetation, such as Spartina patens, Schoenoplectus pungens, etc..
Fruits: July - September
Instructions for submitting your survey information or other additional reporting requirements can be found at
the end of this letter.
Your submission information indicates that your project requires a state permit, license, registration, or
authorization, or utilizes state funding or involves state agency action. This NDDB - New determination may
be utilized to fulfill the Endangered and Threatened Species requirements for state-issued permit
applications, licenses, registration submissions, and authorizations.
Please be aware of the following limitations and conditions:
Natural Diversity Database information includes all information regarding listed species available to us at the
time of the request. This information is a compilation of data collected over the years by the Department of
Energy and Environmental Protection's Natural History Survey and cooperating units of DEEP, land owners,
private conservation groups and the scientific community. This information is not necessarily the result of
comprehensive or site-specific field investigations. Current research projects and new contributors continue
to identify additional populations of species and locations of habitats of concern, as well as enhance existing
data. Such new information is incorporated into the Database and accessed through the ezFile portal as it
becomes available. New information may result in additional review, and new or modified restrictions or
conditions may be necessary to remain in compliance with certain state permits.
e During your work listed species may be encountered on site. A report must be submitted by the
observer to the Natural Diversity Database promptly and additional review and restrictions or conditions
may be necessary to remain in compliance with certain state permits. Please fill out the appropriate
survey form and follow the instructions for submittal.
e Your project involves the state permit application process or other state involvement, including state
funding or state agency actions; please note that consultations with your permit analyst or the agency
may result in additional requirements. In this situation, additional evaluation of the proposal by the
DEEP Wildlife Division may be necessary and additional information, including but not limited to
species-specific site surveys, may be required. Any additional review may result in specific restrictions
or conditions relating to listed species that may be found at or in the vicinity of the site.
e If your project involves preparing an Environmental Impact Assessment, this NDDB consultation and
determination should not be substituted for biological field surveys assessing on-site habitat and
species presence.
e The NDDB - New determination for the Mamacoke Brook Channel Restoration as described in the
File HTMI.£19/5/2074 8:54:44 AM1

1. Vincent.Long@ct.gov
2. deep.nddbrequest@ct.gov
If you have further questions, please contact me at the following:
Vincent Long
CT DEEP Bureau of Natural Resources
Wildlife Division
Natural Diversity Database
79 Elm Street
Hartford, CT 06106-5127
(860) 502-9786
Vincent.Long@ct.gov
Please reference the Determination Number 202508660 when you e-mail or write. Thank you for consulting
the Natural Diversity Data Base.
Vincent Long
Wildlife Division- Natural Diversity Data Base
79 Elm Street
Hartford, CT 06106-5127
(860) 502-9786
Vincent.Long@ct.gov
ile HTMT.112/5/2025 8:54:44 AMI

Project Sub-type:
Stream channel/Streambank modification
Project Name:
Mamacoke Brook Channel Restoration
Project Description:



PARAMETER
1, SUBSTRATE
Greater than 70% of substrate
40 to 70% cover and mix of diverse
20 to 40% mix of stable cover;
Less than 20%, stable
DIVERSITY/ consisting of mix of boulder stable habitat (boulder, cobble, habilat availabilily less than cover; lack of habitat
AVAILABLE slabs, boulders, cobble, snags, LWD); well svited for full cover desirable; substrate frequently is obvious; substrate.
BENTHIC, or other stable habitat providing potential; adequate habitat for disturbed or removed. LWD fow in |_ unstable or lacking. Few.
SALAMANDER, | cover for salamanders and maintenance of populations; density and/or may be new fail or in’ areas suitable for trapping:
CRAYFISH, AND | aquatic or terrestrial invertebrates. | presence of additional LWD inthe | early decay stage. Some areas organic matter.
LAND SNAIL LWO in moderate to advanced form of new fall. Substrate suitable for trapping organic matter:
COVER stage of decay and within- active | roughness still capable of trapping | if tg. boulders are absent, score
channel; Substrate roughness organic matter, tow.
SCORE: capable of trapping lots of organic
matter. If moss covered, rate high.
20 19 18 #17 #16 18.140 43-5 12.4) 105° 9 BT G Cee, tee ate seen oes |
2, EMBEDDED. | Lg. cobble, small boulder, or wood} Lg. cobble, small boulder, or wood | Lg.cobble, small boulder, or wood | Cobble, small boulder; or
NESS particles are between 0 and particles are between 25 and particles are between 50 and 75% | wood particles are
Examine at least} 25% surrounded by fine 50% surrounded by fine sediment. | surrounded by fine sediment. over 75% surrounded by:
10 particles (e.g.,j sediment; layering of cobble or fine sediment.
5 particles from | boulders provides a diversity of
2 different steps)| niche space.
SCORE:
20: 219 1B AF AB AS Abe AR A 14 Goyo 8 7 & 5.40 324-0
Channelization, culverting, or Minor channelization present, Channelization may be extensive; | Banks shored with gabion
3. CHANNEL other channel disturbance absent | usually in areas of culverts, fords, | Embankments, berms or shoring | or cement; over 80% of
ALTERATION | or minimal; stream with normal or bridge abutments; evidence of | structures present on both banks; | the stream reach is
pattern. No crossings (fords) in past channel disturbance, i.e. and 40% to 80% of the stream channelized and
assessment reach. dredging, or realignment (> than reach channelized or disrupted. disrupted. instream.
SCORE: past 20 years)may be present, but habital greatly altered or
no evidence of recent channel Ped Coty (ant Br (dave entirely removed, Stream
disturbance. evidence 0 ¢ yea channel may be used as.a.
a - toad or logging skid trait.
CHOC ZOFIO
20:0.419 18817 46 1B AM AB ADA 40. @) 8 76 Eee Seek tee een ee)
4. FINE
SEDIMENT Little or no enlargement of Some new increase in bar formation] Maderate deposition of new gravel,| Heavy deposits of fine
DEPOSITION mid-channel bars or point bars mostly from find gravel, sand, or silt;|_ sand or fine sediment on old and | material: increased bar
(at bends) and less than 5% of the} 5 to 30% of the bottom new bars; 30-50% of boltom is development; more. than.
Consider non- bottom is affected by fine is affected; some deposition of aifected; sediment deposits at 50% of bottom is fines. and
natural sources | sediment deposition (silt, sand, fines in pools. Leafpacks moderately obstructions, constrictions, and changing frequently with flow;
of sediment fine gravel). Pool rocks with covered in sill. bends; deposition of fines in pools | pools almost absent due
minimal silt layering, leafpacks prevalent; leafpacks may be to substantial sediment
SCORE: relatively clean.