Stormwater Management Report - January 20010
STORMWATER MANAGEMENT REPORT
FOR
BAYBROOK PROFESSIONAL PARK
SUBDIVISION
Town of Queensbury, New York
Warren County
Prepared by: NACE ENGINEERING, P.C.
169 HAVILAND ROAD
QUEENSBURY, NY 12804
Cja v c�-
Thomas W. Nace, P.E.
January 2001
File: #46148
STORMWATER MANAGEMENT REPORT
FOR
BAYBROOK PROFESSIONAL PARK SUBDIVISION
INTRODUCTION
The site of the proposed Baybrook Professional Park Subdivision is on the east side of Bay Road,
opposite Walker Lane, in the Town of Queensbury, NY. The entire site extends through to
Meadowbrook Road and contains approximately 86 acres. The proposed subdivision contains 16
lots of various sizes. The subdivision will be accessed by a loop road off of Bay Road and will
have a short cul-de-sac at the rear. Future development of the rear of the property will likely
include an extension of the cul-de-sac on through to Meadowbrook Road.
This report addresses drainage issues pertaining only to the development of the subdivision roads
and infrastructure. Development of the individual lots will include on -site stormwater
management to address added impervious areas on the individual lots.
EXISTING CONDITIONS
The site is a gently sloping meadow. There is a stream (Old Maids Brook) flowing north to south
across the west portion of the site. There are two areas of freshwater wetlands which have been
flagged by NYSDEC. These are also ACOE wetlands with boundaries slighth different from the
NYSDEC boundaries. However, all of the ACOE boundaries fall within the 100 foot buffer of
the NYSDEC wetlands. There are also two additional small areas of ACOE wetlands. All of the
wetlands are shown on the design drawings.
Soils within the area of the proposed subdivision are generally Raynham silt loams. Seven deep
test pits were dug in the areas of the proposed subdivision. All of the pits encountered very fine
sand, silts or clay loams over clay subsoils. Evidence of seasonal high groundwater was present
in all of the test pits at depths varying from 11/2 to 3 feet.
Groundcover on the existing site is predominantly overgrown meadow with some brush. There
are some forested areas along the southern portion of the site.
All existing drainage from the portion of the site to be developed runs off into Old Maids Brook
as it crosses the site. This brook flows into the wetland along the southern portion of the site and
eventually finds its way across the adjacent Bay Meadows Golf Course and into Halfway Brook.
DRAINAGE METHODOLOGY
Since the existing soils are relatively impermeable and the groundwater is high. it is not practical
to use subsurface infiltration to disperse of the storm runoff from the subdivision. Therefore, a
storm sewer system is proposed to collect the runoff. These storm sewers will outfall into Old
Maids Brook. The outfalls will incorporate detention basins to allow the collected stormwater to
outlet into the brook at approximately the same rate that it presently reaches the brook. These
basins will be shallow and will incorporate a rip -rap surfaced overflow spillway. The basins will
be sized to store the runoff from a 50 year design storm.
New culverts will be installed at two locations where the proposed subdivision roads cross Old
Maids Brook. These culverts have been sized by analyzing the entire upstream drainage basin of
Old Maids Brook. Drainage areas for this drainage basin are shown on the plan included with
the culvert analysis. This plan also labels the components of the drainage system as they are
modeled in the HydroCAD analysis.
CALCULATIONS
All computations SCS TR-20 HydroCAD.
50 year storm event — Type Il rainfall=4.8" — for detention basin and storm sewer sizing
25 year storm event - Type II rainfall = 4.6" — for culvert sizing
Soil conditions —very fine sands. silts & clay loams — SCS soil group C
Runoff rate and volume computations for the 50 year storm event have been completed for both
the pre -developed and developed conditions. Detention basins have been sized to maintain
adequate freeboard during a 50 year design storm. Road culverts have been sized to provide
adequate capacity for a 25 year design storm without submerging the inlet or storing water at the
upstream end of the culvert.
See attached HydroCAD analysis for all computations.
CONCLUSIONS
Detention Pond #1
Pre -developed peak runoff rate - 0.70 cfs
Post development peak runoff rate - 0.78 cfs
Detention Pond #2
Pre -developed peak runoff rate - 0.83 cfs
Post development peak runoff rate - 0.81 cfs
Detention Pond #3
Pre -developed peak runoff rate - 0.92 cfs
Post development peak runoff rate - 0.85 cfs
Detention Pond #4
Pre -developed peak runoff rate - 0.28 cfs
Post development peak runoff rate - 0.31 cfs
2
r
Based upon the attached HydroCAD analysis, the detention basins have sufficient capacity to
manage all runoff generated by the subdivision roads during a 50 year storm event and post
development runoff will be maintained at pre -developed level.
0
0
STORMWATER MANAGEMENT REPORT
FOR
PAYBROOK PROFESSIONAL PARK
SUBDIVISION
HydroCAD RESULTS
e
EXISTING CONDITIONS
Data for 46148-BAYBRO• PROF. PARK -EXIST. CONDITIONS Page 1
TYPE II 24-HOUR RAINFALL= 4.80 IN
Prepared by NACE ENGINEERING, P.C. 1 Feb 01
HydroCAD 5 11 000576 (c) 1986-1999 Applied Microcomputer Systems
WATERSHED ROUTING ________________---------- ----------------------------= -
OSUBCATCHMENT ❑ REACH /\POND LINK
SUBCATCHMENT 1 = ROAD #1 TO INTERSECTION
SUBCATCHMENT 2 = ROAD #2 SAY ROAD TO STA. 9,00 ->
SUBCATCHMENT 3 ROAD #1 PAST INTERSECTION ->
SUBCATCHMENT 4 = ROAD #2 STATION 9 TO END ->
Data for 46148-BAYBR*K PROF. PARK -EXIST. CONDITION* Page 2
TYPE II 24-HOUR RAINFALL= 4.80 IN
Prepared by NACE ENGINEERING, P.C. 1 Feb 01
HydroCAD 5.11 000576 (c) 1986-1999 Applied Microcomputer Systems
SUBCATCHMENT 1 ROAD #1 TO INTERSECTION
PEAK= .70 CFS @ 12.49 HRS, VOLUME= .09 AF
ACRES CN
.83 65 MEADOW
SCS TR-20 METHOD
TYPE II 24-HOUR
RAINFALL= 4.80 IN
SPAN- 10-20 HRS, dt=.1 HRS
Method
Comment
To (min)
TR-55 SHEET FLOW
ACROSS GRASS
48.7
Grass: Dense n=.24 L=300' P2=2.4
in s=.012
SHALLOW CONCENTRATED/UPLAND FLOW
ACROSS GRASS TO
STREAM
1.6
Grassed Waterway Kv=15 L=160'
s=.012 '/' V=1.64
fps
Total Length=
460 ft Total Tc=
50.3
SUBCATCHMENT 2 ROAD #2 BAY ROAD TO STA. 9+00
PEAK- .83 CFS @ 12.49 HRS, VOLUME= .11 AF
ACRES CN
.98 65 MEADOW
SCS TR-2' METHOD
TYPE II 24-HOUR
RAINFALL= 4.80 IN
SPAN= 10-20 HRS. dt=.1 HRS
Method
Comment
Tc (min)
TR-55 SHEET FLOW
ACROSS GRASS
47.1
Grass: Dense n=.24 L=300' P2=2.4
in s=.013
SHALLOW CONCENTRATED/UPLAND FLOW
ACROSS GRASS TO
STREAM
2.9
Grassed Waterway Kv=15 L=260'
5=.01 '/' V=1.5
fps
Total Length=
560 ft
-otal To= 50.0
UBCATCHMENT 3 ROAD #1 PAST INTERSECTION
PEAK- .92 CFS @ 12.54 HRS, VOLUME= .13 AF
ACRES CN
SCS TR-20 METHOD
1.15 65 MEADOW
TYPE II
24-HOUR-
RAINFALL=
4.80 IN
SPAN- 10-20
HRS, dt=.1
HRS
Method
Comment
Tc
(min
TR-55 SHEET FLOW
ACROSS
GRASS
50.4
Grass: Dense n=.24 L=300' P2=2.1
in
s=.013
SHALLOW CONCENTRATED/UPLAND FLOW
ACROSS
GRASS TO
WETLAND
3.2
Grassed Waterway Kv=15 L=350'
s=.015
'/' V=1.84
fps
Total
Length=
650 ft
Total Tc=
53.6
Data for 46148-BAYBROOK PROF. PARK -EXIST. CONDITIONS• Page 3
TYPE II 24-HOUR RAINFALL= 4.80 IN
Prepared by NACE ENGINEERING, P.C. 1 Feb 01
HydroCAD 5.11 000576 (c) 1986-1999 Applied Microcomputer Systems
SUBCATCHMENT 4 ROAD #2 STATION 9 TO END
PEAK= .28 CFS @ 12.69 HRS, VOLUME= .04 AF
ACRES CN
.40 65 MEADOW
SCS TR-20 METHOD
TYPE II 24-HOUR.
RAINFALL= 4.80 IN
SPAN- 10-20 HRS, dt=.1 HRS
TR-55 SHEET FLOW ACROSS GRASS 64.8
Grass: Dense n=.24 L=350' P2=2.4 in s=.008 '/'
•
0
STORMWATER MANAGE•_MENT REPORT
FOR
BAYBROOK PROFESSIONAL, PARK
SUBDIVISION
HydroCAD RESULTS
DEVELOPED CONDITIONS
Data for 46148 BAYBROOK•PROFESSIONAL PARK Page 1
TYPE II 24-HOUR RAINFALL= 4.80 IN- DEVELOPED
Prepared by NACE ENGINEERING, P.C. 1 Feb 01
HydrOCAD 5.11 000576 (c) 1986-1999 Applied Microcomputer Systems
WATERSHED ROUTING -------------------- ______________________________________
�>ry E l n j? ,.7 a I-r a �s
Oa 0
( ��2 O �❑a 4 [ 5] -iA
OSUBCATCHMENT ❑ REACH
O---> F-3� --�A
POND �] LINK
SUBCATCHMENT
1
= ROAD
#1
TO CB #1 & 2
->
REACH 1
SUBCATCHMENT
2
= ROAD
#1
CB #1/2 TO HIGH POINT
->
REACH 2
SUBCATCHMENT
3
= ROAD
#2
CB #10/11 TO END
->
REACH 3
SUBCATCHMENT
4
= CB #7/8
TO CB #10/11
->
REACH 5
SUBCATCHMENT
5
= ROAD
#2
START TO CB #5/6
->
REACH 4
SUBCATCHMENT
6
= ROAD
#2
HIGH POINT TO CB #12/13
->
REACH 6
SUBCATCHMENT
7
= ROAD
#2
CB #12/13 TO CB #14/15
->
REACH 7
SUBCATCHMENT
8
= ROAD
#2
CB #14/15 TO END
->
REACH 8
REACH 1
= CB#1
TO
CB#3
->
REACH 2
REACH 2
= CB#4
TO
POND #1
->
POND 1
REACH 3
= CB#9
TO
POND #4
->
POND 4
REACH 4
= CB#6
TO
CB#8
->
REACH 5
REACH 5
= CB#8
TO
POND #2
->
POND 2
REACH 6
= CB#13
TO CB#15
->
REACH 7
REACH 7
= CB#15
TO CB#17
->
REACH 8
Data for 46148 HAYBROOK•PROFESSIONAL PARK - DEVELOPED Page 2
TYPE II 24-HOUR RAINFALL= 4.80 IN
Prepared by NACE ENGINEERING, P.C. 1 Feb 01
HvdroCAD 5.11 000576 (c) 1986-1999 Applied Microcomputer Systems
REACH 8 = CB#17 TO POND #3 -> POND 3
POND 1 = POND #1 ->
POND 2 = POND #2
POND 3 = POND #3
POND 4 = POND 44 ->
Data for 46148 BAYBROO PROFESSIONAL PARK - DEVELOPED • Page 3
TYPE II 24-HOUR RAINFALL= 4.80 IN
Prepared by NACE ENGINEERING, P.C. 1 Feb 01
HydrOCAD 5 11 000576 (c) 1986-1999 Applied Microcomputer Systems
SUBCATCHMENT 1 ROAD #1 TO CB #1 & 2
PEAK= 1.12 CPS @ 11.86 HRS, VOLUME= .05 AF
ACRES
CN
.13
98 PAVEMENT
.11
61 GRASS
.24
81
SCS TR-20 METHOD
TYPE II 24-HOUR
RAINFALL= 4.80 IN
SPAN= 10-20 HRS, dt=.1 HRS
Method Comment Tc (min)
TR-55 SHEET FLOW ACROSS ROAD TO WING .3
Smooth surfaces n=.011 L=12' P2=2.4 in s=.02
RECT/VEE/TRAP CHANNEL WING SWALE TO CB .9
D=.S' SS= .02 & .25 '/' a=6.75 sq-ft Pw=27.1' r=.249'
s=.008 '/' n=.013 V=4.05 fps L=210' Capacity=27.3 cfs
Total Length= 222 ft Total Tc= 1.2
SUBCATCHMENT 2 ROAD #1 CB #1/2 TO HIGH POINT
PEAK- 2.90 CFS @ 11.86 HRS, VOLUME= .13 AF
ACRES CN SCS TR-20 METHOD
.33 98 PAVEMENT TYPE II 24-HOUR
.26 61 GRASS RAINFALL= 4.80 IN
.59 82 SPAN= 10-20 HRS, dt=.1 HRS
Method Comment Tc (min)
TR-55 SHEET FLOW ACROSS ROAD TO WING .3
Smooth surfaces n=.011 L=12' P2=2.4 in s=.02
RECT/VEE/TRAP CHANNEL WING SWALE TO CB 1.3
D=.5' SS- .02 & .25 '/' a=6.75 sq-ft Pw=27.1' r=.249'
s=.008 '/' n=.013 V=4.05 fps L=320' Capacity=27.3 cfs
Total Length= 332 ft Total Tc= 1.6
SUBCATCHMENT 3 ROAD #2 CB #10/11 TO END
PEAK- 1.93 CPS @ 11.87 HRS, VOLUME= .09 AF
ACRES CN SCS TR-20 METHOD
.22 98 PAVEMENT TYPE II 24-HOUR
.18 61 GRASS RAINFALL= 4.80 IN
.40 81 SPAN= 10-20 HRS, dt=.1 HRS
Method Comment Tc (min)
TR-55 SHEET FLOW ACROSS ROAD TO WING .3
Smooth surfaces n=.011 L=12' P2=2.4 in s=.02
RECT/VEE/TRAP CHANNEL WING SWALE TO CB 1.5
D=.S' SS= .02 & .25 '/' a=6.75 sq-ft Pw=27.1' r=.249'
s=.007 '/' n=.013 V=3.79 fps L=350' Capacity=25.6 cfs
Total Length= 362 ft Total Tc= 1.8
Data for 46148 BAYBROOPROFESSIONAL PARK - DEVELOPED Page 4
TYPE II 24-HOUR RAINFALL= 4.80 IN
Prepared by NACE ENGINEERING, P.C. 1 Feb 01
HydroCAD 5.11 000576 (c) 1986-1999 Applied Microcomputer Systems
SUBCATCHMENT 4
CB #7/8
TO CB #10/11
PEAK= 2.81 CPS @ 11.86
HRS, VOLUME=
.13 AF
ACRES CN
SCS TR-20 METHOD
.32 98 PAVEMENT
TYPE II 24-HOUR.
.25 61 GRASS
RAINFALL- 4.80 IN
.57 82
SPAN= 10-20 HRS, dt=.1
HRS
Method
Comment
To
(min)
TR-55 SHEET FLOW
ACROSS ROAD TO
WING
.3
Smooth surfaces n=.011
L=12'
P2=2.4 in s=.02
RECT/VEE/TRAP CHANNEL
WING TO CB
1.4
D=.5' SS= .02 & .25 '/'
a-6.75
sq-ft Pw=27.1'
r=.249'
s=.007 '/' n=.013 V=3.79
fps
L-320' Capacity=25.6
cfs
Total Length=
332 ft Total To=
1.7
SUBCATCHMENT 5
ROAD #2
START TO CB #5/6
PEAK= 1.93 CFS @ 11.87
HRS, VOLUME-
.09 AF
ACRES CN
SCS TR-20 METHOD
.22 98 PAVEMENT
TYPE II 24-HOUR
.18 61 GRASS
RAINFALL= 4.80 IN
.40 81
SPAN= 10-20 HRS, dt=.1
HRS
Method
Comment
To
(min)
TR-55 SHEET FLOW
ACROSS ROAD TO
WING
.3
Smooth surfaces n=.011
L=12'
P2=2.4 in s=.02
RECT/VEE/TRAP CHANNEL
WING TO CB
1.5
D=.5' SS= .02 & .25 '/'
a=6.75
sq-ft Pw=27.1'
r=.249'
s=.0075 '/' n=.013 V=3.92
fps
L=350' Capacity=26.5
cfs
Total Length=
362 ft Total To=
1.8
SUBCATCHMENT 6 ROAD #2 HIGH POINT TO CB #12/13
PEAK= 2.38 CPS @ 11.86 HRS, VOLUME- .11 AF
ACRES ON SCS TR-20 METHOD
.24 98 PAVEMENT TYPE II 24-HOUR
.19 74 GRASS RAINFALL= 4.80 IN
.43 87 SPAN= 10-2C HRS, dt=.1 HRS
Method Comment To (min)
TR-55 SHEET FLOW ACROSS ROAD TO WING .3
Smooth surfaces n=.011 L=12' P2=2.4 in s=.02
RECT/VEE/TRAP CHANNEL WING TO CB 1.3
D=.5' SS= .02 & .25 '/' a=6.75 sq-ft Pw=27.1' r=.249'
s=.01 '/' n=.013 V=4.53 fps L=350' Capacity=30.6 cfs
Total Length= 362 ft Total To= 1.6
Data for 46148 BAYBROOK PROFESSIONAL PARK - DEVELOPED • Page 5
TYPE II 24-HOUR RAINFALL= 4.80 IN
Prepared by NACE ENGINEERING, P.C. 1 Feb 01
HydroCAD 5 11 000576 (c) 1986-1999 Applied Microcomputer Systems
SUBCATCHMENT 7 ROAD #2 CB #12/13 TO CB #14/15
PEAK= 1.05 CPS @ 11.84 HRS, VOLUME= .05 AF
ACRES CN SCS TR-20 METHOD
.11 98 PAVEMENT TYPE II 24-HOUR
.09 74 GRASS RAINFALL= 4.80 IN
.20 87 SPAN= 10-20 HRS, dt=.1 HRS
Method Comment Tc (min)
TR-55 SHEET FLOW ACROSS ROAD TO WING .3
Smooth surfaces n=.011 L=12' P2=2.4 in s=.02
RECT/VEE/TRAP CHANNEL WING TO CB .6
D=.5' SS- .02 & .25 '/' a=6.75 sq-ft Pw=27.1' r=.249'
s=.01 '/' n=.013 V-4.53 fps L=175' Capacity=30.6 cfs
Total Length= 187 ft Total Tc= .9
SUBCATCHMENT 8 ROAD #2 CB #14/15 TO END
PEAK= 2.85 CFS @ 11.85 HRS, VOLUME= .13 AF
ACRES CN SCS TR-20 METHOD
.29 98 PAVEMENT TYPE II 24-HOUR
.22 74 GRASS RAINFALL= 4.80 IN
.51 88 SPAN= 10-20 HRS, dt=.1 HRS
Method Comment Tc (min)
TR-55 SHEET FLOW ACROSS ROAD TO WING .3
Smooth surfaces n=.011 L=12' P2=2.4 in s=.02
RECT/VEE/TRAP CHANNEL WING TO CB 1.0
D=.5' SS= .02 & .25 '/' a=6.75 sq-ft Pw=27.1' r=.249'
s=.01 '/' n=.013 V=4.53 fps L-280' Capacity=30.6 cfs
Total Length= 292 ft Total Tc= 1.3
Data for 46148 BAYBROP PROFESSIONAL PARK - DEVELOPED Page 6
TYPE II 24-HOUR RAINFALL= 4.80 IN
Prepared by MACE ENGINEERING, P.C. 1 Feb 01
HydroCAD 5.11 000576 (c) 1986-1999 Applied Microcomputer Systems
REACH 1
CB#1 TO CB#3
Qin = 1.12 CFS @ 11.86 HRS, VOLUME= .05 AF
Qout= 1.09 CFS @ 11.87 HRS, VOLUME= .05 AF, ATTEN= 3%, LAG=
DEPTH END AREA DISCH
(FT)
(SO -FT)
(CFS)
0.00
0.00
0.00
.10
.04
.07
.20
.11
.30
.30
.20
.67
.70
.59
2.85
.80
.67
3.33
.90
.74
3.63
.94
.77
3.66
.97
.78
3.63
1.00
.79
3.40
REACH 2
12" PIPE
n= .01
LENGTH= 185 FT
SLOPE= .0054 FT/FT
CB#4 TO POND #1
1.1 MIN
STOR-IND+TRANS METHOD
PEAK DEPTH= .38 FT
PEAK VELOCITY= 4.0 FPS
TRAVEL TIME _ .8 MIN
SPAN= 10-20 HRS. dt=.1 HRS
Qin = 3.98 CFS @ 11.87 HRS, VOLUME= .18 AF
Qout= 3.92 CFS @ 11.87 HRS, VOLUME- .18 AF, ATTEN= 2%, LAG- .4 MIN
DEPTH END AREA DISCH
(FT)
(SO -FT)
(CFS)
15" PIPE
0.00
0.00
0.00
.13
.06
.12
n= .01
.25
.17
.52
LENGTH= 100 FT
.38
.31
1.16
SLOPE= .005 FT/FT
.88
.92
4.97
1.00
1.05
5.80
1.13
1.16
6.33
1.18
1.20
6.39
1.21
1.22
6.33
1.25
1.23
5.94
STOR-IND+TRANS METHOD
PEAK DEPTH= .73 FT
PEAK VELOCITY= 5.2 FPS
TRAVEL TIME _ .3 MIN
SPAN= 10-20 HRS, dt=.1 HRS
REACH 3 CB#9 TO POND #4
Qin = 1.93 CFS @ 11.87 HRS, VOLUME= .09 AF
Qout= 1.84 CFS @ 11.88 HRS, VOLUME= .09 AF, ATTEN= 5%, LAG=
DEPTH END AREA - DISCH
(FT)
(SO -FT)
(CFS)
0.00
0.00
0.00
.10
.04
.07
.20
.11
.29
.30
.20
.64
.70
.59
2.74
.80
.67
3.20
.90
.74
3.49
.94
.77
3.52
.97
.78
3.49
1.00
.79
3.28
12" PIPE
n= .01
LENGTH= 180 FT
SLOPE= .005 FT/FT
8 MIN
STOR-IND+TRANS METHOD
PEAK DEPTH= .53 FT
PEAK VELOCITY= 4.4 FPS
TRAVEL TIME _ .7 MIN
SPAN= 10-20 HRS, dt=.1 HRS
Data for 46148 BAYBROOK PROFESSIONAL PARK - DEVELOPED • Page 7
TYPE II 24-HOUR RAINFALL= 4.80 IN
Prepared by MACE ENGINEERING, P.C. 1 Feb 01
HydroCAD 5 11 000576 (c) 1986-1999 Applied Microcomputer Systems
REACH 4
CB#6 TO CB#8
Qin = 1.93 CPS @ 11.87 HRS, VOLUME= .09 AF
Qout= 1.85 CFS @ 11.88 HRS, VOLUME= .09 AF
DEPTH END AREA DISCH
(FT)
(SO -FT)
(CFS)
12" PIPE
0.00
0.00
0.00
.10
.04
.07
n= .01
.20
.11
.29
LENGTH= 170 FT
.30
.20
.64
SLOPE= .005 FT/FT
.70
.59
2.74
.80
.67
3.20
.90
.74
3.49
.94
.77
3.52
.97
.78
3.49
1.00
.79
3.28
REACH
5
CB#8
TO POND #2
Qin
= 4.65 CFS @ 11.87
HRS,
VOLUME=
Qout=
4.63 CFS @ 11.87
HRS,
VOLUME=
DEPTH END AREA DISCH
(FT)
(SO -FT)
(CFS)
12" PIPE
0.00
0.00
0.00
.10
.04
.10
n= .01
.20
.11
.41
LENGTH= 30 FT
.30
.20
.91
SLOPE= .01 FT/FT
.70
.59
3.88
.80
.67
4.53
.90
.74
4.94
.94
.77
4.98
.97
.78
4.94
1.00
.79
4.63
REACH 6
CB#13 TO CB#15
Qin = 2.38 CFS @ 11.86 HRS, VOLUME=
Qout= 2.33 CFS @ 11.87 HRS, VOLUME=
DEPTH END
(FT) (SO
AREA
-FT)
DISCH
(CFS)
0.00 0.00
0.00
.10
.04
.10
.20
.11
.40
.30
.20
.89
.70
.59
3.82
.80
.67
4.46
.90
.74
4.86
.94
.77
4.91
.97
.78
4.86
1.00
.79
4.56
12" PIPE
ATTEN= 4%. LAG= .7 MIN
STOR-IND+TRANS METHOD
PEAK DEPTH= .53 FT
PEAK VELOCITY= 4.4 FPS
TRAVEL TIME _ .6 MIN
SPAN= 10-20 HRS, dt=.1 HRS
21 AF
21 AF, ATTEN= 0%, LAG- .1 MIN
STOR-IND+TRANS METHOD
PEAK DEPTH= .79 FT
PEAK VELOCITY= 6.7 FPS
TRAVEL TIME _ .1 MIN
SPAN= 10-20 HRS, dt=.1 HRS
11 AF
11 AF, ATTEN= 2%, LAG=
n= .01
LENGTH= 170 FT
SLOPE= .0097 FT/FT
6 MIN
STOR-IND+TRANS METHOD
PEAK DEPTH= .49 FT
PEAK VELOCITY= 6.0 FPS
TRAVEL TIME = .5 MIN
SPAN= 10-20 HRS, dt=.1 HRS
Data for 46148 BAYBRO• PROFESSIONAL PARK - DEVELOPED • Page 8
TYPE II 24-HOUR RAINFALL= 4.80 IN
Prepared by NACE ENGINEERING, P.C. 1 Feb 01
HydroCAD 5.11 000576 (c) 1986-1999 Applied Microcomputer Systems
REACH 7
CB015 TO CB#17
Qin = 3.38 CPS @ 11.86 HRS, VOLUME= .16 AF
QOut= 3.26 CFS @ 11.88 HRS, VOLUME= .16 AF, ATTEN= 4%, LAG- .9 MIN
DEPTH END
(FT) (SO
AREA
-FT)
DISCH
(CPS)
0.00 0.00
0.00
.10
.04
.09
.20
.11
.38
.30
.20
.85
.70
.59
3.62
.80
.67
4.22
.90
.74
4.60
.94
.77
4.65
.97
.78
4.60
1.00
.79
4.32
REACH 8
12" PIPE
n= .01
LENGTH= 258 FT
SLOPE= .0087 FT/FT
CB#17 TO POND #3
STOR-IND+TRANS METHOD
PEAK DEPTH= .65 FT
PEAK VELOCITY= 6.1 FPS
TRAVEL TIME _ .7 MIN
SPAN= 10-20 HRS, dt=.1 HRS
Qin = 6.07 CFS @ 11.87 HRS, VOLUME= .29 AF
Qout= 6.00 CPS @ 11.87 HRS, VOLUME= .29 AF, ATTEN= 1%, LAG=
DEPTH END AREA DISCH
(FT)
(SO -FT)
(CFS)
15" PIPE
0.00
0.00
0.00
.13
.06
.15
n= .01
.25
.17
.64
LENGTH- 117 FT
.38
.31
1.42
SLOPE= .0075 FT/FT
.88
.92
6.09
1.00
1.05
7.11
1.13
1.16
7.75
1.18
1.20
7.82
1.21
1.22
7.75
1.25
1.23
7.27
4 MIN
STOR-IND+TRANS METHOD
PEAK DEPTH- .85 FT
PEAK VELOCITY= 6.6 FPS
TRAVEL TIME _ .3 MIN
SPAN- 10-20 HRS, dt=.1 HRS
u
Data for 46148 BAYBROOKPROFESSIONAL PARK - DEVELOPED • Page 9
TYPE II 24-HOUR RAINFALL= 4.80 IN
Prepared by MACE ENGINEERING, P.C. 1 Feb 01
HydroCAD 5.11 000576 (c) 1986-1999 Applied Microcomputer Systems
POND 1 POND #1
Qin = 3.92 CFS @ 11.87 HRS, VOLUME=
Qout= .78 CFS @ 12.08 HRS, VOLUME=
ELEVATION AREA INC.STOR CUM.STOR
(FT) (SF) (CF) (CF)
0.0 0 0 0
1.0 1000 500 500
2.0 2000 1500 2000
3.0 3000 2500 4500
18 AF
18 AF, ATTEN= 80%, LAG- 12.6 MIN
STOR-IND METHOD
PEAK STORAGE = 2883 CF
PEAK ELEVATION= 2.4 FT
FLOOD ELEVATION= 3.0 FT
START ELEVATION= 0.0 FT
SPAN= 10-20 HRS, dt=.1 HRS
Tdet= 34.3 MIN (.18 AF)
# ROUTE INVERT OUTLET DEVICES
1 P 0.0' 4.5" ORIFICE/GRATE
Q=.6 PI r-2 SQR(2g) SQR(H-r) (Use H/2 if H<d)
POND 2 POND #2
Qin = 4.63 CFS @ 11.87 HRS, VOLUME=
Qout= .81 CFS @ 12.10 HRS, VOLUME=
ELEVATION AREA INC.STOR CUM.STOR
(FT) (SF) (CF) (CF)
0.0 0 0 0
.3 1510 227 227
1.3 2056 1783 2010
2.3 2651 2354 4363
2.8 2900 1388 5751
21 AF
21 AF, ATTEN= 82%, LAG= 13.6 MIN
STOR-IND METHOD
PEAK STORAGE = 3680 CF
PEAK ELEVATION= 2.0 FT
FLOOD ELEVATION= 2.8 FT
START ELEVATION= 0.0 FT
SPAN= 10-20 HRS, dt=.1 HRS
Tdet= 47.7 MIN (.21 AF)
# ROUTE INVERT OUTLET DEVICES
1 P 0.0' 4.8" ORIFICE/GRATE
Q=.6 PI r_2 SQR(2g) SQR(H-r) (Use H/2 if H<d)
POND 3 POND #3
Qin = 6.00 CFS @ 11.87 HRS, VOLUME=
Qout= .85 CFS @ 12.10 HRS, VOLUME -
ELEVATION AREA INC.STOR CUM.STOR
(FT) (SF) (CF) (CF)
0.0 0 0 0
.3 3469 520 520
1.3 6051 4760 5280
2.3 7950 7000 12281
2.8 9500 4363 16643
29 AF
28 AF, ATTEN= 86%, LAG- 13.6 MIN
STOR-IND
METHOD
PEAK
STORAGE =
5834
CF
PEAK
ELEVATION=
1.4
FT
FLOOD
ELEVATION=
2.8
FT
START
ELEVATION=
0.0
FT
SPAN-
10-20 HRS,
dt-.1
HRS
Tdet=
79.8 MIN (.28
AF)
# ROUTE INVERT OUTLET DEVICES
1 P 0.0' 5.5" ORIFICE/GRATE
Q=.6 PI r_2 SQR(2g) SQR(H-r) (Use H/2 if H<d)
Data for 46148 BAYBROO1PROFESSIONAL PARK - DEVELOPED • Page 10
TYPE II 24-HOUR RAINFALL= 4.80 IN
Prepared by NACE ENGINEERING, P.C. 1 Feb 01
HydroCAD 5.11 000576 (c) 1986-1999 Applied Microcomputer Systems
POND 4
POND #4
Qin = 1.84 CFS @ 11.88 HRS, VOLUME=
Qout= .31 CFS @ 12.12 HRS, VOLUME=
ELEVATION
AREA
INC.STOR
CUM.STOR
(FT)
(SF)
(CF)
(CF)
0.0
0
0
0
.5
689
172
172
1.5
1034
862
1034
2.5
1430
1232
2266
3.0
1800
808
3073
09 AF
08 AF, ATTEN= 830, LAG= 14.7 MIN
STOR-IND
METHOD
PEAK
STORAGE =
1477
CF
PEAK
ELEVATION=
1.9
FT
FLOOD
ELEVATION=
3.0
FT
START
ELEVATION=
0.0
FT
SPAN=
10-20 HRS,
dt=.1
HRS
Tdet=
46.7 MIN (.08
AF)
# ROUTE INVERT OUTLET DEVICES
1 P 0.0' 3" ORIFICE/GRATE
Q=.6 PI r-2 SQR(2g) SQR(H-r) (Use H/2 if H<d)
STORNIWATER MANAGEMENT REPORT
FOR
BAYBROOK PROFESSIONAL PARK
SUBDIVISION
HydroCAD RESULTS
STREAM CULVERT SIZING
n
�� • N �y F 1�Ct, tira s
f
ROq
�(CC p��l �, - '. HA_ Ill �LJ L) 4
35
le_ /
-' Adirondack C01plounity
350
_
�Olf Cho rsp c o�XI
jl
I ,
Sri 1
PF, V" Goll Course
Sri o
Data for BAYBROOK SUBD.- EXISTING WATERSHED Page 1
TYPE II 24-HOUR RAINFALL= 4.40 IN
Prepared by MACE ENGINEERING, P.C. 1 Feb 01
HydroCAD 5.11 000576 (c) 1986-1999 Applied Microcomputer Systems
WATERSHED ROUTING ---------------__-----------------________________
O
v
O 0
z
O
0
OSUBCATCHMENT REACH
SUBCATCHMENT 1 = SUBCATCH 1
SUBCATCHMENT 2 = SUBCATCH 2
SUBCATCHMENT 3 = SUBCATCH 3
REACH 1 = UPPER STREAM
REACH 2 = MIDDLE STREAM
REACH 3 = LOWER STREAM
APOND
LINK
->
REACH 1
->
REACH 2
->
REACH 3
->
REACH 2
->
REACH 3
->
POND 1
POND 1 = NEW CULVERT WITH UPSTREAM STORAGE ->
Data for BAYBROOK SUBD.- EXISTING WATERSHED • Page 2
TYPE II 24-HOUR RAINFALL= 4.40 IN
Prepared by MACE ENGINEERING, P.C. 1 Feb 01
HydroCAD 5.11 000576 (c) 1986-1999 Applied Microcomputer Systems
SUBCATCHMENT 1 SUBCATCH 1
PEAK- 5.14 CFS @ 12.89 HRS, VOLUME= 1.68 AF
ACRES CN SCS TR-20 METHOD
97.30 45 WOODS, BRUSH, SOME DEVELOPMENT TYPE II 24-HOUR
RAINFALL= 4.4 IN
SPAN= 10-20 HRS, dt=.1 HRS
Method Comment Tc (min)
TR-55 SHEET FLOW Segment ID: 45.3
Woods: Light underbrush n=.4 L=300' P2=2.4 in s=.04 '/'
SHALLOW CONCENTRATED/UPLAND FLOW Segment ID: 9.6
Woodland Kv=5 L=500' s=.03 '/' V=.87 fps
SUBCATCHMENT 2
SUBCATCH 2
Total Length= 800 ft Total Tc= 54.9
PEAK= 35.49 CFS @ 12.64 HRS, VOLUME= 6.36 AF
ACRES CN SCS TR-20 METHOD
105.00 52 WOODS, BRUSH TYPE II 24-HOUR
25.00 70 DEVELOPED AREA RAINFALL= 4.4 IN
130.00 55 SPAN= 10-20 HRS, dt=.1 HRS
Method Comment Tc (min)
TR-55 SHEET FLOW Segment ID: 45.3
Woods: Light underbrush n=.4 L=300' P2=2.4 in s=.04
SHALLOW CONCENTRATED/UPLAND FLOW Segment ID: 9.6
Woodland Kv=5 L=500' s=.03 '/' V=.87 fps
SUBCATCHMENT 3
SUBCATCH 3
Total Length= 800 ft Total Tc= 54.9
PEAK= 64.30 CFS @ 12.42 HRS, VOLUME= 7.73 AF
ACRES CN SCS TR-20 METHOD
43.10 80 DEVELOPED AREAS INC. ROADS TYPE II 24-HOUR
RAINFALL= 4.4 IN
SPAN= 10-20 HRS, dt=.1 HRS
Method Comment Tc (min)
TR-55 SHEET FLOW Segment ID: 39.7
Grass: Dense n=.24 L=300' P2=2.4 in s=.02
SHALLOW CONCENTRATED/UPLAND FLOW Segment ID: 7.9
Kv=6 L=400' s=.02 '/' V=.85 fps
Total Length= 700 ft Total Tc= 47.6
Data for BAYBROOK SUB EXISTING WATERSHED • Page 3
TYPE II 24-HOUR RAINFALL= 4.40 IN
Prepared by MACE ENGINEERING, P.C. 1 Feb 01
HydroCAD 5.11 000576 (c) 1986-1999 Applied Microcomputer Systems
REACH 1
UPPER STREAM
Qin = 5.14 CPS @ 12.89 HRS, VOLUME= 1.68 AF
Qout= 4.46 CFS @ 13.38 HRS, VOLUME= 1.60 AF, ATTEN= 13%, LAG= 29.1 MIN
DEPTH
(FT)
END AREA
(SO -FT)
DISCH
(CFS)
0.00
0.00
0.00
.30
1.98
1.82
.60
4.32
5.98
.90
7.02
12.20
1.29
11.07
23.42
1.80
17.28
43.72
2.40 25.92 76.48
3.00 36.00 119.75
REACH 2
6' x 3' CHANNEL
SIDE SLOPE= .5
n= .05
LENGTH= 2000 FT
SLOPE= .0055 FT/FT
MIDDLE STREAM
STOR-IND METHOD
PEAK DEPTH= .49 FT
PEAK VELOCITY= 1.3 FPS
TRAVEL TIME = 25.9 MIN
SPAN= 10-20 HRS, dt=.1 HRS
Qin = 37.04 CFS @ 12.67 HRS, VOLUME= 7.96 AF
Qout- 32.62 CFS @ 12.93 HRS, VOLUME= 7.74 AF, ATTEN= 12%, LAG= 15.7 MIN
DEPTH END AREA DISCH
(FT)
(SO
-FT)
(CFS)
0.00
0.00
0.00
.30
1.98
2.33
.60
4.32
7.65
.90
7.02
15.61
1.29
11.07
29.96
1.80
17.28
55.93
2.40
25.92
97.84
3.00
36.00
153.19
REACH 3
6' x 3' CHANNEL
SIDE SLOPE= .5 '/'
n= .05
LENGTH= 3000 FT
SLOPE= .009 FT/FT
LOWER STREAM
STOR-IND METHOD
PEAK DEPTH= 1.34 FT
PEAK VELOCITY= 2.8 FPS
TRAVEL TIME = 18.0 MIN
SPAN= 10-20 HRS, dt=.1 HRS
Qin = 80.32 CFS @ 12.55 HRS, VOLUME= 15.47 AF
Qout= 78.35 CFS @ 12.65 HRS, VOLUME= 15.30 AF, ATTEN= 2%, LAG=
DEPTH END AREA DISCH
(FT)
(SO -FT)
(CFS)
0.00
0.00
0.00
.30
1.98
2.33
.60
4.32
7.65
.90
7.02
15.61
1.29
11.07
29.96
1.80 17.28 55.93
2.40 25.92 97.84
3,00 36.00 153.19
6' x 3' CHANNEL
SIDE SLOPE= .5
n= .05
LENGTH= 1600 FT
SLOPE= .009 FT/FT
5.9 MIN
STOR-IND METHOD
PEAK DEPTH= 2.12 FT
PEAK VELOCITY= 3.6 FPS
TRAVEL TIME = 7.5 MIN
SPAN= 10-20 HRS, dt=.1 HRS
' Data for BAYBROOK SUBD.- EXISTING WATERSHED Page 4
TYPE II 24-HOUR RAINFALL= 4.40 IN
Prepared by NACE ENGINEERING, P.C. 1 Feb 01
HydroCAD 5.11 000576 (c) 1986-1999 Applied Microcomputer Systems
POND 1 NEW CULVERT WITH UPSTREAM STORAGE
Qin = 78.35 CFS @ 12.65 HRS, VOLUME= 15.30 AF
Qout= 78.43 CPS @ 12.68 HRS, VOLUME= 15.26 AF, ATTEN= 0%, LAG= 1.6 MIN
ELEVATION AREA INC.STOR CUM.STOR STOR-IND METHOD
(FT) (SF) (CF) (CF) PEAK STORAGE = 3984 CF
0.0 100 0 0 PEAK ELEVATION= 3.1 FT
1.0 500 300 300 FLOOD ELEVATION= 4.0 FT
2.0 1500 1000 1300 START ELEVATION= 0.0 FT
3.0 3000 2250 3550 SPAN= 10-20 HRS, dt=.1 HRS
4.0 6000 4500 8050 Tdet= 1.7 MIN (15.26 AF)
# ROUTE INVERT OUTLET DEVICES
1 P 0.0' 42" CULVERT X 2
n=.01 L=80' S=.005'/' Ke=.5 Cc=.9 Cd=.6 TW=2.2'