Conservation Commission Regular Meeting Materials (linked)

PRELIMINARY 
STORMWATER MANAGEMENT REPORT 
WATERFORD WOODS APARTMENTS 
384 & 394 WILLETTS AVE. EXT. 
WATERFORD, CT 
PREPARED FOR 
SIG CON ASSOCIATES, LLC 
606 POST ROAD EAST #320 
WESTPORT, CT 06880 
DATE: 
NOVEMBER 18, 2020 
REVISED: 


 
 
 
WATERFORD WOODS APARTMENTS 
 
384 & 394 WILLETTS AVE. EXT. 
 
WATERFORD, CONNECTICUT 
 
 
 
 
 
 
TOC 
TABLE OF CONTENTS 
 
PROJECT DESCRIPTION ........................................................................................................................ 1 
EXISTING SITE DESCRIPTION ............................................................................................................. 1 
PEAK FLOW & FLOOD PROTECTION ................................................................................................. 2 
 
PRE-DEVELOPED CONDITIONS ................................................................................................. 2 
 
POST-DEVELOPED CONDITIONS .............................................................................................. 3 
 
COMPARISON ................................................................................................................................ 3 
 
INFILTRATION & DETENTION ................................................................................................... 4 
STORMWATER QUALITY AND TREATMENT ................................................................................... 5 
 
WATER QUALITY VOLUME & FLOW ....................................................................................... 5 
 
GROUNDWATER RECHARGE VOLUME ................................................................................... 6 
CONCLUSION .......................................................................................................................................... 6 
APPENDICES 
A. DRAINAGE MAPS 
B. HYDROLOGIC COMPUTATIONS (Hydrograph Summary Report) 
C. STORMWATER TREATMENT COMPUTATIONS 
D. SUPPLEMENTAL DATA 
TABLES 
1. PEAK FLOW COMPARISON – EXISTING VS. PROPOSED (NO DETENTION) ................. 3 
2. PEAK FLOW COMPARISON – EXISTING VS. PROPOSED (WITH DETENTION) ............. 4 
3. PROPOSED TREATMENT SUMMARY .................................................................................... 5 


 
WATERFORD WOODS APARTMENTS 
 
384 & 394 WILLETTS AVE. EXT. 
 
WATERFORD, CONNECTICUT 
1 
PROJECT DESCRIPTION 
 
Sig Con Associates, LLC is proposing to construct a residential multi-family development on two 
undeveloped parcels of land on the south side of Willetts Avenue Extension totaling 26.64 acres. 
• 0.48-acre parcel located at 384 Willetts Avenue Extension identified as Map 140, Lot 9190 
on the Town of Waterford Tax Assessor Mapping 
• 26.16-acre parcel located at 394 Willetts Avenue Extension identified as Map 140, Lot 9192 
on the Town of Waterford Tax Assessor Mapping 
The combined parcels are hereinafter referred to as the Site. 
The Site is in the Commercial Multi-Family District (C-MF).  Per Section 16.1.2 of the Zoning 
Regulations multi-family developments are listed as a permitted use within the district, which requires 
a Site Plan approval per Section 18.1.a.   
The multi-family development will consist of the construction of three (3) apartment buildings with a 
total of 98 units with a mix of 58 one-bedroom and 40 two-bedroom dwelling units.  Main access to 
the development will be provided from the north via Willetts Avenue Extension. Additional site work 
will include: 
• Clearing and grubbing. 
• Demolition and removal of the existing outbuilding on 384 Willetts Avenue Extension. 
• Excavation and disposal of construction and demolition debris stockpiled throughout the Site. 
• Construction of a new curb cut to the north on Willetts Avenue Extension. 
• 28’ main access drive with 24’ wide internal access drives including a looped connection to 
improve vehicular circulation and emergency access throughout the development. 
• Paved parking situated in close proximity to the apartment buildings and site amenities with a 
total of 167 spaces including 6 handicapped accessible. 
• Concrete pedestrian sidewalks connecting the apartment buildings with interior amenities and 
the existing public sidewalk along the south shoulder of Willetts Avenue Extension. 
• Outdoor recreation areas including a mix of active recreation, passive recreation, and 
community spaces. 
• Drainage improvements including a stormwater collection network, grass-lined treatment 
swales, subsurface infiltration systems, and detention ponds. 
• Connection to water, sewer, electric, gas and telecom services in Willetts Avenue Extension. 
• Landscaping including a mixture of street trees, shrubs, foundation plantings and planting beds 
• Building and street lighting. 
• Erosion and sedimentation control measures. 
EXISTING SITE DESCRIPTION  
The subject Site is currently undeveloped except for a small outbuilding along Willetts Avenue 
Extension.  The Site is generally wooded with an internal network of gravel roads leading to stockpiles 
of construction and demolition debris, such as brick, concrete, timber, and etc.  There are also signs of 
rock quarrying at the southwest corner of the site. 

 
WATERFORD WOODS APARTMENTS 
 
384 & 394 WILLETTS AVE. EXT. 
 
WATERFORD, CONNECTICUT 
2 
TOPOGRAPHY – The existing topography generally consists of gentle to moderately sloping terrain 
from the northeast along Willetts Avenue to the southwest towards two (2) wetland areas on Site and 
Fenger Brook.  Existing slopes in the upland areas of the Site range from 4% to 7% with steeper slopes 
around the perimeter of the delineated inland wetland areas. 
SOILS – The USDA NRCS Web Soil Survey indicates that the upland area of the Site contain 
Charlton-Chatfield complex, 0 to 15 percent slopes, very rocky (73C) soils, which have a hydrologic 
soil group classification (HSG) of B.  Inland wetland areas are designed as Ridgebury, Leicester, and 
Whitman soils, 0 to 8 percent slopes, very rocky, which have an HSG of D.  Deep observation test 
holes were performed at the site, which generally confirmed the NRCS soil types within upland areas. 
DRAINAGE – The Site drains from the northeast along Willetts Avenue towards wetland systems to 
the southwest and south.  Three (3) existing drainage areas were delineated based upon topography 
and field observation. 
• SITE-EX-01 is 8.182 acres and consists of the northern portion of the site, which drains to a 
wetland area along the westerly property line. 
• SITE-EX-02 is 2.495 acres and consists of the southeastern corner of the site draining to a 
wetland area along the east and southern property line. 
• SITE-EX-03 is 6.764 acres and consists of a peninsula of upland at the southeast corner of the 
site, which drains from a high point at the center to the perimeter wetlands. 
Based upon CT DEEP mapping, the entire Site lies within the Southeast Shoreline subregional 
drainage basin 2000, which is part of the Southeast Coast major basin 2.  However, based upon the 
“Jordan Brook Watershed Management Plan Final Report, Town of Waterford, Connecticut”, dated 
February 2000, prepared by Fuss & O’Neill, Inc., the Site is included within the Jordan Brook 
subregional basin 2201 (hereinafter JBWMP).  A detailed review of the hydrologic conditions of the 
subregional watershed was not performed as part of this review, however the recommendations of the 
JBWMP were followed as a conservative measure. 
PEAK FLOW CONTROL & FLOOD PROTECTION 
 
Stormwater runoff from the proposed multi-family development will be collected through a series of 
rain gardens, swales, yard drains, catch basins, and drainage piping and discharged to a series of 
treatment, infiltration, and detention areas on the Site.   
Peak flow rates for pre-development and post-development conditions were calculated using SCS TR-
55 methodology.  Hydrology Studio 2020 v.3.0.0.16 was used to generate peak flows from the 
watershed with the following parameters: 
PRE-DEVELOPED CONDITIONS (Drainage Area Map DA-01A) 
• DRAINAGE AREAS:  As described above, the Site has three (3) existing drainage areas. 
o SITE-EX-01 is 8.182 acres and consists of the northern portion of the site, which drains to a 
wetland area along the westerly property line. 
o SITE-EX-02 is 2.495 acres and consists of the southeastern corner of the site draining to a 
wetland area along the east and southern property line. 
o SITE-EX-03 is 6.764 acres and consists of a peninsula of upland at the southeast corner of the 
site, which drains from a high point at the center to the perimeter wetlands. 

 
WATERFORD WOODS APARTMENTS 
 
384 & 394 WILLETTS AVE. EXT. 
 
WATERFORD, CONNECTICUT 
3 
• RAINFALL: Precipitation frequency and depth estimates (rainfall data) were obtained from 
NOAA Atlas 14, Volume 10, Version 2 at Lat. 41.3376 Long. -72.1197, which corresponds with 
the geographic location of the Site. 
• RUNOFF COEFFICIENT: Composite Curve Numbers (CN) were calculated based on the land 
cover types for the site for HSG B.  Land cover types consist of impervious buildings and 
pavement, meadow/brush, open space vegetated areas, woods, and wetlands.  Wetland areas were 
excluded from the drainage areas and calculations.   
• TIME OF CONCENTRATION:   Time of concentration (Tc) was estimated for the basin based 
on the SCS method, with sheet and shallow concentrated flow from the hydraulically most distant 
point of the watershed to the discharge point.   
POST-DEVELOPED CONDITIONS (Drainage Area Map DA-02A) 
• DRAINAGE AREA:  For direct comparison with existing conditions, the same three design points 
were evaluated. 
o SITE-PR-01 is 6.988 acres and consists of the north/northwest portion of the developed site. 
o SITE-PR-02 is 3.689 acres and consists of the eastern portion of the developed site. 
o SITE-PR-03 is 6.764 acres consists of a peninsula of upland at the southeast corner. There is 
no change from existing conditions. 
• RAINFALL: Same as Pre-Developed Conditions. 
• CURVE NUMBER: Same methodology as Pre-Developed Conditions. Composite Curve 
Numbers (CN) were calculated based on the land cover types for the proposed multi-family 
residential development for HSG B. 
• TIME OF CONCENTRATION:   Same methodology as Pre-Developed Conditions. 
COMPARISON 
A summary of flows for existing and proposed conditions, without consideration of infiltration or 
detention is provided below with a complete output provided in the enclosed Hydrology Studio Report. 
STORM 
EVENT 
AREA 01 
AREA 02 
AREA 03 
TOTAL SITE 
SITE-
EX-01 
SITE-
PR-01 
EX 
SITE-
EX-02 
SITE-
PR-02 
EX 
SITE-
EX-03 
SITE-
PR-03 
EX 
SITE-
EX 
SITE-
PR 
EX 
vs. 
vs. 
vs. 
vs. 
PR 
PR 
PR 
PR 
2-yr 
1.15 
4.62 
3.47 
0.30 
2.80 
2.50 
0.81 
0.81 
0.00 
2.26 
7.20 
4.94 
5-yr 
3.09 
7.90 
4.80 
0.86 
4.62 
3.76 
2.34 
2.34 
0.00 
6.29 
14.44 
8.15 
10-yr 
5.20 
10.88 
5.68 
1.49 
6.26 
4.77 
4.03 
4.03 
0.00 
10.71 
20.72 
10.01 
25-yr 
8.63 
15.31 
6.68 
2.52 
8.66 
6.14 
6.83 
6.83 
0.00 
17.98 
30.34 
12.36 
50-yr 
11.45 
18.70 
7.25 
3.37 
10.50 
7.13 
9.14 
9.14 
0.00 
23.95 
37.82 
13.87 
100-yr 
14.69 
22.46 
7.77 
4.36 
12.51 
8.15 
11.82 
11.82 
0.00 
30.85 
46.19 
15.34 
TABLE 1: PEAK FLOW COMPARISON - EXISTING VS. PROPOSED (NO DETENTION) 
As shown in the table above, the proposed multi-family development (SITE-PR) results in an increase 
in peak flow rates as compared to existing conditions (SITE-EX) without consideration of infiltration 

 
WATERFORD WOODS APARTMENTS 
 
384 & 394 WILLETTS AVE. EXT. 
 
WATERFORD, CONNECTICUT 
4 
or detention.  To attenuate peak flow rates, subsurface infiltration and detention ponds are proposed, 
which will collect runoff from the collection network and attenuate peak flow rates and volumes.  
Further discussion is provided below. 
INFILTRATION & DETENTION (Drainage Area Map DA-03A) 
The proposed stormwater network consists of a series of infiltration and detention methods to attenuate 
peak flow rates. 
PROPOSED AREA 01A (PR-01A) 
Stormwater runoff within PR-01A will discharge to the following structures: 
• INF-01A – Stormtech SC-740 subsurface infiltration systems consisting of 20 units to promote 
treatment and infiltration. 
• INF-01B – Stormtech SC-740 subsurface infiltration systems consisting of 40 units to promote 
treatment and infiltration. 
• POND-01A – Wet extended detention pond used for peak runoff attenuation with a shallow 5” 
deep wet pool to promote treatment and infiltration. 
o POND-01A will discharge through outlet control structure 01A (OCS 01A) with staged 
outlets to regulate outflow, emergency overflow weir, and riprap plunge pool to 
dissipate energy and velocity before flowing towards the downstream wetlands. 
PROPOSED AREA 02A (PR-02A) 
Stormwater runoff within PR-02A will discharge to the following structures: 
• POND-02A – Wet extended detention pond used for peak runoff attenuation with a shallow 9” 
deep wet pool to promote treatment and infiltration from contributing area. 
o POND-02A will discharge through outlet control structure 02A (OCS 02A) with staged 
outlets to regulate outflow, emergency overflow weir, and riprap plunge pool to 
dissipate energy and velocity before flowing towards the downstream wetlands. 
The combination of subsurface infiltration systems and wet extended detention ponds have been sized 
to attenuate peak flow rates and volumes as compared to pre-development conditions for the 2-, 5-, 
10-, 25-, 50-, and 100-year storm events.  
STORM 
EVENT 
AREA 01 
AREA 02 
AREA 03 
TOTAL SITE 
SITE-
EX-01 
SITE-
PR-
01A 
EX 
SITE-
EX-02 
SITE-
PR-
02A 
EX 
SITE-
EX-03 
SITE-
PR-03 
EX 
SITE-
EX 
SITE-
PR-
DET-
A 
EX 
vs. 
vs. 
vs. 
vs. 
PR 
PR 
PR 
PR 
2-yr 
1.15 
1.19 
0.04 
0.30 
0.34 
0.04 
0.81 
0.81 
0.00 
2.26 
2.24 
-0.01 
5-yr 
3.09 
2.56 
-0.53 
0.86 
0.80 
-0.07 
2.34 
2.34 
0.00 
6.29 
5.27 
-1.02 
10-yr 
5.20 
4.23 
-0.97 
1.49 
1.25 
-0.24 
4.03 
4.03 
0.00 
10.71 
9.36 
-1.36 
25-yr 
8.63 
7.01 
-1.62 
2.52 
1.97 
-0.55 
6.83 
6.83 
0.00 
17.98 
15.61 
-2.37 
50-yr 
11.45 
8.89 
-2.56 
3.37 
2.68 
-0.69 
9.14 
9.14 
0.00 
23.95 
20.51 
-3.44 
100-yr 
14.69 
12.15 
-2.54 
4.36 
3.54 
-0.82 
11.82 
11.82 
0.00 
30.85 
26.11 
-4.74 
TABLE 2: PEAK FLOW COMPARISON - EXISTING VS. PROPOSED (WITH DETENTION) 

 
WATERFORD WOODS APARTMENTS 
 
384 & 394 WILLETTS AVE. EXT. 
 
WATERFORD, CONNECTICUT 
5 
As shown in Table 2 above, incorporation of the infiltration and detention systems into the proposed 
development results in a minor decrease in peak flow rates as compared to existing conditions for the 
entire Site.  Although the results show a negligible increase for the 2-year storm within subarea 01 and 
02, these minor increases are eliminated for entire Site due to offsetting times to peak flow. The plan 
provides for zero net increase in peak flow rates and volumes for all storms up to the 100-year event. 
STORMWATER QUALITY & TREATMENT  
 
The proposed development has been designed to reduce stormwater runoff and pollutant loads to the 
maximum extent possible and to treat the required water quality volume and flow per the CT DEEP 
2004 Stormwater Quality Manual (2004 DEEP Manual).  The proposed measures incorporated into 
the plan include: 
• Maximize conservation and preservation of natural features. Impervious surfaces and buildings 
generally fall within historic limits of site disturbance activities.  Stone walls, rock outcrops, 
and specimen trees have been preserved. 
• Minimize clearing and grubbing maintain native vegetation on site.  Where clearing of the 
mature tree vegetation is proposed within 50’ of the delineated inland wetlands, native shrubs 
are proposed and conservation seed mix will be placed to provide a minimum 50’ upland 
protection zone as recommended in the JBWMP. 
• Minimize building footprint.  Buildings have been designed to accommodate site grades and 
unit areas were condensed to maximizing the number of units in a limit footprint area. 
• Minimize impervious surfaces for roadways and parking.  Curb cuts and access drives are the 
minimum required for adequate site access and the proposed parking quantity is the minimum 
allowed per zoning requirements.  Impervious area totals 11.5% of the total site, which is 
substantially lower than the 18% to 30% impervious cover referenced in Section 3.1.2.3 of the 
JBWMP for “intermediate” level uses such as multi-family. 
• Disconnect impervious areas where possible, such as sidewalks. Disconnected impervious 
areas were not subtracted from the treatment calculations as a conservative measure. 
• Collect, treat, and infiltrate to encourage groundwater recharge including the incorporation of 
base level and secondary controls to improve water quality as recommended by the JBWMP. 
WATER QUALITY VOLUME & FLOW (Drainage Area Map DA-04A) 
Water quality volumes and flows were calculated for all proposed impervious surfaces for the 
driveway, parking and building areas in accordance with the 2004 DEEP Manual. 
AREA 
DA 
IA 
WQV 
WQF 
PROPOSED TREATMENT 
Label 
acre 
acre 
acre-ft 
cfs 
Method 
Vol 
Flow 
Note 
01A-1 
1.674 
0.505 
0.045 
0.370 
Sedimentation & Filter Pond 
0.093 
N/A 
100% WQV Retention 
01A-2 
2.556 
0.658 
0.060 
0.495 
Isolator Row 
N/A 
3.0 
100% WQF Treatment 
01A-3 
0.280 
0.135 
0.011 
0.127 
Vegetated Swale to Wet Pond 
0.041 
N/A 
100% WQV Retention 
01B-1 
0.950 
0.544 
0.045 
0.504 
Isolator Row 
N/A 
1.35 
100% WQF Treatment 
02A-1 
2.525 
1.221 
0.102 
0.804 
HG4 to Wet Pond 
0.090 
0.8 
100% WQF Treatment 
TABLE 3: PROPOSED TREATMENT SUMMARY 

 
WATERFORD WOODS APARTMENTS 
 
384 & 394 WILLETTS AVE. EXT. 
 
WATERFORD, CONNECTICUT 
6 
As shown in Table 3 above, the proposed treatment measures will adequately retain the calculated 
water quality volume and/or treat the calculated water quality flow, removing 80% or more of total 
suspended solids and floatable debris for the first inch of rainfall before discharging to the Site 
wetlands 
GROUNDWATER RECHARGE VOLUME  
Existing non-wetland soils are classified as Charlton-Chatfield complex (HSG B) and the wetland 
soils as Ridgebury, Leicester, and Whitman (HSG D).  Required Groundwater Recharge Volumes 
(GRV) were calculated in accordance with 2004 DEEP Manual based upon the area of each 
Hydrologic Soil Group. 
GRV (required) 
= 0.041 acre-feet 
GRV (provided) = 0.140 acre-feet 
The combination of sediment and filtration basins, subsurface infiltration systems, and shallow 
depressions within each wet extended detention pond provide adequate capacity to fully retain over 3 
times the recommended groundwater recharge volume, thereby exceeding the GRV requirement. 
CONCLUSION 
There will be no increase in peak flow rates or volumes discharging to the downgradient wetlands or 
adjacent properties. The stormwater network will maintain approved drainage patterns and utilize a 
combination of subsurface infiltration and detention ponds to regulate any increase in run-off on site.  
No adverse impacts to the site, adjacent wetlands, or municipal system are anticipated.   

 
 
 
WATERFORD WOODS APARTMENTS 
 
384 & 394 WILLETTS AVENUE EXT. 
 
WATERFORD, CONNECTICUT 
 
 
 
 
 
 
APPENDIX A 
DRAINAGE AREA MAPS 
Existing Conditions DA-01A 
Proposed Conditions DA-02A 
Proposed Detention DA 03A 
Proposed Treatment DA-04A 
 


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DOUBLE YELLOW
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SOLID WHITE
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SOLID WHITE
24 in. WATER MAIN
12 in. WATER MAIN
12 in. METAL
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EVERSOURCE 
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OLD HELTCO 
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CATCH BASIN, TF=60.87, INV
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HELTCO POLE  
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CATCH BASIN, TF=64.25, INV IN=61.95, INV
6 in. GAS MAIN
SMH90
SMH91
SMH92
INV IN=69.76, INV OUT=68.66
CATCH BASIN, TF=72.26
8 in. SANITARY MAIN
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42 in.
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42 in.
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WETLAND AREA
WOODED 
WETLAND AREA
WOODED 
WETLAND AREA
WOODED 
WETLAND AREA
WOODED 
AREA
WOODED
AREA
WOODED
AREA
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AREA
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AREA
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#390
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DECK
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GRASS 
DRIVEWAY
ASPHALT 
SIDEWALK
ASPHALT 
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HOUSE 
#396A
BUILDING 
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BUILDING
PORCH
BOULDERS
LARGE 
ROCKS AND 
PILE OF 
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                           WATERFORD, CT
CONTACT INFORMATION
LEBANON, CONN 06249
191 NORWICH AVENUE
YANTIC RIVER CONSULTANTS, LLC
www.yanticriverconsultants.com
Web:
yanticriver@gmail.com
Email:
(860) 367-7264
Phone:
384 & 394 WILLETTS AVE. EXT.        
SCALE:   1" =   160'
00096 - 001  
 160
0
 160
PROJECT NO:
DATE:
SHEET NO:
11/18/20
DA-01A
                       WATERFORD WOODS                      
                   PREPARED FOR SIG CON ASSOCIATES, LLC                   
        DRAINAGE MAP - EXISTING CONDITIONS SITE ONLY        
73C
73C
3
17
3
306
61C
W ILLETTS AVENUE EXTENSION
LEGEND
77(D)
WETLANDS (WOODS)
55
WOODS (GOOD)
58
MEADOW/BRUSH
61
OPEN SPACE (GOOD)
98
IMPERVIOUS
NRCS SOIL
TC PATH - CHANNEL
TC PATH - SHALLOW
TC PATH - SHEET
D.A. LIMIT
CN B
ITEM
WOODS (GOOD) = 6.872
MEADOW/BRUSH (GOOD) = 0.434
OPEN SPACE (GOOD) = 0.818
IMPERVIOUS = 0.058
TOTAL AREA = 8.182 AC
DRAINAGE AREA 'SITE-EX-01'
AREA = 3.609 AC
WETLANDS
AREA = 5.585 AC
WETLANDS
WOODS (GOOD) = 6.764
TOTAL AREA = 6.764 AC
DRAINAGE AREA 'SITE-EX-03'
FOR HYDROLOGIC ANALYSIS
AREA FOLLOWS PROPERTY LINE
DOWNSTREAM LIMIT OF DRAINAGE
FOR HYDROLOGIC ANALYSIS
AREA FOLLOWS PROPERTY LINE
DOWNSTREAM LIMIT OF DRAINAGE
BOUNDARY
NRCS SOIL
FOR HYDROLOGIC ANALYSIS
AREA FOLLOWS PROPERTY LINE
UPSTREAM LIMIT OF DRAINAGE
WOODS (GOOD) = 2.495
TOTAL AREA = 2.495 AC
DRAINAGE AREA 'SITE-EX-02'
ELEV.= 71±
ELEV.= 60±
MEADOW/WOODS @ 5.5%
SHEET FLOW - 200'
WOODS @ 4.8%
SHALLOW CONC.- 650'
ELEV.= 44±
ELEV.= 34±
ELEV. = 29±
INLAND WETLANDS
DISCHARGE POINT AT
ELEV. = 22±
INLAND WETLANDS
DISCHARGE POINT AT
MEADOW/WOODS @ 5.0%
SHEET FLOW - 200'
WOODS @ 5.7%
SHALLOW CONC.- 210'

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#10
WF
#9
WF
#8
WF
#7
WF
#6
WF
#5
WF
#4
WF
#1
WF
#26
WF
#25
WF
#24
WF
#23
WF
#22
WF
#21
WF
#3
WF
#19
WF
WF#18
#16
WF
#13,14
WFs
#15
WF
#20
WF
 CENTERLINE STRIPE
DOUBLE YELLOW
 STRIPE
 SHOULDER
SOLID WHITE
 STRIPE
 SHOULDER
SOLID WHITE
 OAK
42 in.
 OAK
42 in.
#17
WF
#48
WF
#49
WF
#50
WF
#52
WF
#53
WF
#54
WF
#55
WF
#56
WF
#57
WF
#58
WF
#59
WF
#60
WF
#61
WF
#62
WF
#63
WF
#64
WF
#65
WF
#66
WF
#67
WF
#68
WF
#69
WF
#70
WF
#71
WF
#72
WF
#73
WF
#74
WF
#75
WF
WF#76
#77
WF
#78
WF
#79-81
WFs
#84
WF
#85
WF
#86
WF
#88
WF
#87
WF
#89
WF
#90
WF
#91
WF
#92
WF
#93B
WF
#93
WF
#94
WF
#35
WF
#28
WF
#29
WF
#30
WF
#31
WF
#32
WF
#33
WF
#27
WF
#34
WF
#36
WF
#37
WF
#38
WF
#39
WF
#40
WF
#41
WF
#42
WF
#43
WF
#44
WF
#45
WF
#46
WF
#47
WF
#82
WF
#83
WF
WETLAND AREA
WOODED 
WETLAND AREA
WOODED 
WETLAND AREA
WOODED 
WETLAND AREA
WOODED 
AREA
WOODED
AREA
WOODED
AREA
WOODED
AREA
WOODED
AREA
WOODED
ROAD
WOODS 
ROAD
WOODS 
ROAD
WOODS 
ROAD
WOODS 
#390
HOUSE 
DECK
YARD
GRASS 
DRIVEWAY
ASPHALT 
SIDEWALK
ASPHALT 
#384
HOUSE 
#396A
BUILDING 
 #396
BUILDING
PORCH
BOULDERS
LARGE 
ROCKS AND 
PILE OF 
PILE
DEBRIS 
PILE
BRICK 
PILE
TIRE
MOUND
ROCKY 
S
G
S
S
WG
16
22
22
28
22
22
16
18
22
24
26
28
32
34
36
38
42
44
44
46
48
52
54
56
58
62
64
66
68
72
74
76
74
72
68
66
64
62
58
58
56
54
52
48
46
44
42
38
38
38
36
34
32
28
26
22
18
18
22
24
26
26
24
22
18
16
28
72
48
34
32
28
26
24
28
26
28
28
30
40
50
60
70
70
50
40
30
20
20
20
30
20
30
40
50
20
30
20
44
60
                           WATERFORD, CT
CONTACT INFORMATION
LEBANON, CONN 06249
191 NORWICH AVENUE
YANTIC RIVER CONSULTANTS, LLC
www.yanticriverconsultants.com
Web:
yanticriver@gmail.com
Email:
(860) 367-7264
Phone:
384 & 394 WILLETTS AVE. EXT.        
SCALE:   1" =   160'
00096 - 001  
 160
0
 160
PROJECT NO:
DATE:
SHEET NO:
11/18/20
DA-02A
                       WATERFORD WOODS                      
                   PREPARED FOR SIG CON ASSOCIATES, LLC                   
        DRAINAGE MAP - PROPOSED CONDITIONS SITE ONLY        
73C
73C
3
17
3
306
61C
W ILLETTS AVENUE EXTENSION
LEGEND
77(D)
WETLANDS (WOODS)
55
WOODS (GOOD)
58
MEADOW/BRUSH
61
OPEN SPACE (GOOD)
98
IMPERVIOUS
NRCS SOIL
TC PATH - CHANNEL
TC PATH - SHALLOW
TC PATH - SHEET
D.A. LIMIT
CN B
ITEM
AREA = 3.609 AC
WETLANDS
WOODS (GOOD) = 6.764
TOTAL AREA = 6.764 AC
DRAINAGE AREA 'SITE-EX-03'
AREA = 5.585 AC
WETLANDS
FOR HYDROLOGIC ANALYSIS
AREA FOLLOWS PROPERTY LINE
DOWNSTREAM LIMIT OF DRAINAGE
FOR HYDROLOGIC ANALYSIS
AREA FOLLOWS PROPERTY LINE
DOWNSTREAM LIMIT OF DRAINAGE
BOUNDARY
NRCS SOIL
FOR HYDROLOGIC ANALYSIS
AREA FOLLOWS PROPERTY LINE
UPSTREAM LIMIT OF DRAINAGE
ELEV.= 68±
ELEV.= 59±
GRASS @ 3.3%
SHALLOW CONC.- 900'
GRASS @ 5.5%
SHEET FLOW - 200'
ELEV. = 29±
INLAND WETLANDS
DISCHARGE POINT AT
ELEV. = 22±
INLAND WETLANDS
DISCHARGE POINT AT
ELEV.= 71±
ELEV.= 48±
ELEV.= 62±
ELEV.= 53±
GRASS @ 4.5%
SHEET FLOW - 200'
GRASS @ 4.5%
SHALLOW CONC.- 200'
WOODS (GOOD) = 1.119
OPEN SPACE (GOOD) = 4.003
IMPERVIOUS = 1.866
TOTAL AREA = 6.988 AC
DRAINAGE AREA 'SITE-PR-01'
WOODS (GOOD) = 0.781
OPEN SPACE (GOOD) = 1.685
IMPERVIOUS = 1.223
TOTAL AREA = 3.689 AC
DRAINAGE AREA 'SITE-PR-02'
930' @ 3.3%
SHALLOW CONC.

FENGER
BROOK
#12
WF
#11
WF
#10
WF
#9
WF
#8
WF
#7
WF
#6
WF
#5
WF
#4
WF
#1
WF
#26
WF
#25
WF
#24
WF
#23
WF
#22
WF
#21
WF
#3
WF
#19
WF
WF#18
#16
WF
#13,14
WFs
#15
WF
#20
WF
 CENTERLINE STRIPE
DOUBLE YELLOW
 STRIPE
 SHOULDER
SOLID WHITE
 STRIPE
 SHOULDER
SOLID WHITE
 OAK
42 in.
 OAK
42 in.
#17
WF
#48
WF
#49
WF
#50
WF
#52
WF
#53
WF
#54
WF
#55
WF
#56
WF
#57
WF
#58
WF
#59
WF
#60
WF
#61
WF
#62
WF
#63
WF
#64
WF
#65
WF
#66
WF
#67
WF
#68
WF
#69
WF
#70
WF
#71
WF
#72
WF
#73
WF
#74
WF
#75
WF
WF#76
#77
WF
#78
WF
#79-81
WFs
#84
WF
#85
WF
#86
WF
#88
WF
#87
WF
#89
WF
#90
WF
#91
WF
#92
WF
#93B
WF
#93
WF
#94
WF
#35
WF
#28
WF
#29
WF
#30
WF
#31
WF
#32
WF
#33
WF
#27
WF
#34
WF
#36
WF
#37
WF
#38
WF
#39
WF
#40
WF
#41
WF
#42
WF
#43
WF
#44
WF
#45
WF
#46
WF
#47
WF
#82
WF
#83
WF
WETLAND AREA
WOODED 
WETLAND AREA
WOODED 
WETLAND AREA
WOODED 
WETLAND AREA
WOODED 
AREA
WOODED
AREA
WOODED
AREA
WOODED
AREA
WOODED
AREA
WOODED
ROAD
WOODS 
ROAD
WOODS 
ROAD
WOODS 
ROAD
WOODS 
#390
HOUSE 
DECK
YARD
GRASS 
DRIVEWAY
ASPHALT 
SIDEWALK
ASPHALT 
#384
HOUSE 
#396A
BUILDING 
 #396
BUILDING
PORCH
BOULDERS
LARGE 
ROCKS AND 
PILE OF 
PILE
DEBRIS 
PILE
BRICK 
PILE
TIRE
MOUND
ROCKY 
S
G
S
S
WG
16
22
22
28
22
22
16
18
22
24
26
28
32
34
36
38
42
44
44
46
48
52
54
56
58
62
64
66
68
72
74
76
74
72
68
66
64
62
58
58
56
54
52
48
46
44
42
38
38
38
36
34
32
28
26
22
18
18
22
24
26
26
24
22
18
16
28
72
48
34
32
28
26
24
28
26
28
28
30
40
50
60
70
70
50
40
30
20
20
20
30
20
30
40
50
20
30
20
44
60
                           WATERFORD, CT
CONTACT INFORMATION
LEBANON, CONN 06249
191 NORWICH AVENUE
YANTIC RIVER CONSULTANTS, LLC
www.yanticriverconsultants.com
Web:
yanticriver@gmail.com
Email:
(860) 367-7264
Phone:
384 & 394 WILLETTS AVE. EXT.        
SCALE:   1" =   160'
00096 - 001  
 160
0
 160
PROJECT NO:
DATE:
SHEET NO:
11/18/20
DA-03A
                       WATERFORD WOODS                      
                   PREPARED FOR SIG CON ASSOCIATES, LLC                   
              DRAINAGE MAP - PROPOSED DETENTION             
73C
73C
3
17
3
306
61C
W ILLETTS AVENUE EXTENSION
LEGEND
77(D)
WETLANDS (WOODS)
55
WOODS (GOOD)
58
MEADOW/BRUSH
61
OPEN SPACE (GOOD)
98
IMPERVIOUS
NRCS SOIL
TC PATH - CHANNEL
TC PATH - SHALLOW
TC PATH - SHEET
D.A. LIMIT
CN B
ITEM
AREA = 3.609 AC
WETLANDS
WOODS (GOOD) = 6.764
TOTAL AREA = 6.764 AC
DRAINAGE AREA 'SITE-EX-03'
AREA = 5.585 AC
WETLANDS
FOR HYDROLOGIC ANALYSIS
AREA FOLLOWS PROPERTY LINE
DOWNSTREAM LIMIT OF DRAINAGE
FOR HYDROLOGIC ANALYSIS
AREA FOLLOWS PROPERTY LINE
DOWNSTREAM LIMIT OF DRAINAGE
BOUNDARY
NRCS SOIL
WOODS (GOOD) = 0.027
OPEN SPACE (GOOD) = 1.594
IMPERVIOUS = 0.859
TOTAL AREA = 2.480 AC
DRAINAGE AREA 'POND-01A'
WOODS (GOOD) = 0.000
OPEN SPACE (GOOD) = 1.304
IMPERVIOUS = 1.221
TOTAL AREA = 2.525 AC
DRAINAGE AREA 'POND-02A'
WOODS (GOOD) = 0.000
OPEN SPACE (GOOD) = 1.589
IMPERVIOUS = 0.440
TOTAL AREA = 2.029 AC
DRAINAGE AREA 'INF-01A'
WOODS (GOOD) = 0.000
OPEN SPACE (GOOD) = 0.406
IMPERVIOUS = 0.544
TOTAL AREA = 0.950 AC
DRAINAGE AREA 'INF-01B'
WOODS (GOOD) = 0.781
OPEN SPACE (GOOD) = 0.381
IMPERVIOUS = 0.002
TOTAL AREA = 1.164 AC
DRAINAGE AREA 'PR-02A'
WOODS (GOOD) = 1.092
OPEN SPACE (GOOD) = 0.414
IMPERVIOUS = 0.023
TOTAL AREA = 1.529 AC
DRAINAGE AREA 'PR-01A'

FENGER
BROOK
#12
WF
#11
WF
#10
WF
#9
WF
#8
WF
#7
WF
#6
WF
#5
WF
#4
WF
#1
WF
#26
WF
#25
WF
#24
WF
#23
WF
#22
WF
#21
WF
#3
WF
#19
WF
WF#18
#16
WF
#13,14
WFs
#15
WF
#20
WF
 CENTERLINE STRIPE
DOUBLE YELLOW
 STRIPE
 SHOULDER
SOLID WHITE
 STRIPE
 SHOULDER
SOLID WHITE
 OAK
42 in.
 OAK
42 in.
#17
WF
#48
WF
#49
WF
#50
WF
#52
WF
#53
WF
#54
WF
#55
WF
#56
WF
#57
WF
#58
WF
#59
WF
#60
WF
#61
WF
#62
WF
#63
WF
#64
WF
#65
WF
#66
WF
#67
WF
#68
WF
#69
WF
#70
WF
#71
WF
#72
WF
#73
WF
#74
WF
#75
WF
WF#76
#77
WF
#78
WF
#79-81
WFs
#84
WF
#85
WF
#86
WF
#88
WF
#87
WF
#89
WF
#90
WF
#91
WF
#92
WF
#93B
WF
#93
WF
#94
WF
#35
WF
#28
WF
#29
WF
#30
WF
#31
WF
#32
WF
#33
WF
#27
WF
#34
WF
#36
WF
#37
WF
#38
WF
#39
WF
#40
WF
#41
WF
#42
WF
#43
WF
#44
WF
#45
WF
#46
WF
#47
WF
#82
WF
#83
WF
WETLAND AREA
WOODED 
WETLAND AREA
WOODED 
WETLAND AREA
WOODED 
WETLAND AREA
WOODED 
AREA
WOODED
AREA
WOODED
AREA
WOODED
AREA
WOODED
AREA
WOODED
ROAD
WOODS 
ROAD
WOODS 
ROAD
WOODS 
ROAD
WOODS 
#390
HOUSE 
DECK
YARD
GRASS 
DRIVEWAY
ASPHALT 
SIDEWALK
ASPHALT 
#384
HOUSE 
#396A
BUILDING 
 #396
BUILDING
PORCH
BOULDERS
LARGE 
ROCKS AND 
PILE OF 
PILE
DEBRIS 
PILE
BRICK 
PILE
TIRE
MOUND
ROCKY 
S
G
S
S
WG
16
22
22
28
22
22
16
18
22
24
26
28
32
34
36
38
42
44
44
46
48
52
54
56
58
62
64
66
68
72
74
76
74
72
68
66
64
62
58
58
56
54
52
48
46
44
42
38
38
38
36
34
32
28
26
22
18
18
22
24
26
26
24
22
18
16
28
72
48
34
32
28
26
24
28
26
28
28
30
40
50
60
70
70
50
40
30
20
20
20
30
20
30
40
50
20
30
20
44
60
                           WATERFORD, CT
CONTACT INFORMATION
LEBANON, CONN 06249
191 NORWICH AVENUE
YANTIC RIVER CONSULTANTS, LLC
www.yanticriverconsultants.com
Web:
yanticriver@gmail.com
Email:
(860) 367-7264
Phone:
384 & 394 WILLETTS AVE. EXT.        
SCALE:   1" =   160'
00096 - 001  
 160
0
 160
PROJECT NO:
DATE:
SHEET NO:
11/18/20
DA-04A
                       WATERFORD WOODS                      
                   PREPARED FOR SIG CON ASSOCIATES, LLC                   
              DRAINAGE MAP - PROPOSED TREATMENT             
73C
73C
3
17
3
306
61C
W ILLETTS AVENUE EXTENSION
LEGEND
77(D)
WETLANDS (WOODS)
55
WOODS (GOOD)
58
MEADOW/BRUSH
61
OPEN SPACE (GOOD)
98
IMPERVIOUS
NRCS SOIL
TC PATH - CHANNEL
TC PATH - SHALLOW
TC PATH - SHEET
D.A. LIMIT
CN B
ITEM
BOUNDARY
NRCS SOIL
WOODS (GOOD) = 0.000
OPEN SPACE (GOOD) = 1.304
IMPERVIOUS = 1.221
TOTAL AREA = 2.525 AC
TREATMENT AREA '02A'
WOODS (GOOD) = 0.000
OPEN SPACE (GOOD) = 0.406
IMPERVIOUS = 0.544
TOTAL AREA = 0.950 AC
TREATMENT AREA '01B'
WOODS (GOOD) = 0.011
OPEN SPACE (GOOD) = 1.158
IMPERVIOUS = 0.505
TOTAL AREA = 1.674 AC
TREATMENT AREA '01A-1'
WOODS (GOOD) = 0.003
OPEN SPACE (GOOD) = 1.895
IMPERVIOUS = 0.658
TOTAL AREA = 2.556 AC
TREATMENT AREA '01A-2'
WOODS (GOOD) = 0.014
OPEN SPACE (GOOD) = 0.131
IMPERVIOUS = 0.135
TOTAL AREA = 0.280 AC
TREATMENT AREA '01A-3'

 
 
 
WATERFORD WOODS APARTMENTS 
 
384 & 394 WILLETTS AVENUE EXT. 
 
WATERFORD, CONNECTICUT 
 
 
 
 
 
 
APPENDIX B 
HYDROLOGIC COMPUTATIONS 
HYDROLOGY STUDIO REPORT 
 


Table of Contents
Project Name: Waterford Woods
Hydrology Studio v 3.0.0.16
11-23-2020
Basin Model Schematic
1
......................................................................................................................................
Hydrograph by Return Period
2
............................................................................................................................
2 - Year
Hydrograph Summary
3
..................................................................................................................................
5 - Year
Hydrograph Summary
4
..................................................................................................................................
10 - Year
Hydrograph Summary
5
..................................................................................................................................
25 - Year
Hydrograph Summary
6
..................................................................................................................................
50 - Year
Hydrograph Summary
7
..................................................................................................................................
100 - Year
Hydrograph Summary
8
..................................................................................................................................

Basin Model
Project Name: Waterford Woods
Hydrology Studio v 3.0.0.16
11-23-2020
1

Hydrograph by Return Period
Project Name: Waterford Woods
Hydrology Studio v 3.0.0.16
11-23-2020
Hyd.
No.
Hydrograph
Type
Hydrograph
Name
Peak Outflow (cfs)
1-yr
2-yr
3-yr
5-yr
10-yr
25-yr
50-yr
100-yr
1
NRCS Runoff
EX-01
9.328
20.10
30.75
47.38
60.64
75.64
2
NRCS Runoff
PR-01
14.24
27.12
39.27
57.79
72.27
88.49
3
NRCS Runoff
SITE-EX-01
1.146
3.092
5.196
8.632
11.45
14.69
4
NRCS Runoff
SITE-EX-02
0.299
0.861
1.486
2.519
3.372
4.359
5
NRCS Runoff
SITE-EX-03
0.811
2.335
4.028
6.830
9.141
11.82
6
Junction
SITE-EX
2.256
6.287
10.71
17.98
23.95
30.85
7
NRCS Runoff
SITE-PR-01
4.615
7.896
10.88
15.31
18.70
22.46
8
NRCS Runoff
SITE-PR-02
2.798
4.623
6.259
8.663
10.50
12.51
9
NRCS Runoff
SITE-PR-03
0.811
2.335
4.028
6.830
9.141
11.82
10
Junction
SITE-PR
7.916
14.44
20.72
30.34
37.82
46.19
11
Pond Route
POND-PR-01
0.876
2.949
4.132
8.795
11.56
16.47
12
Pond Route
POND-PR-02
0.244
0.429
0.871
1.410
2.138
3.570
13
Junction
SITE-PR-DET
1.578
5.355
8.228
15.96
21.30
29.90
14
NRCS Runoff
PR-01A
0.311
0.799
1.318
2.155
2.832
3.607
15
NRCS Runoff
POND-01A
2.095
3.372
4.502
6.155
7.407
8.776
16
NRCS Runoff
INF-01A
1.375
2.397
3.326
4.718
5.787
6.966
17
NRCS Runoff
INF-01B
1.803
2.618
3.307
4.283
5.006
5.786
18
NRCS Runoff
PR-02A
0.229
0.594
0.986
1.619
2.131
2.719
19
NRCS Runoff
POND-02A
2.818
4.247
5.481
7.242
8.554
9.976
20
NRCS Runoff
PR-03A
0.810
2.334
4.025
6.826
9.135
11.81
21
Pond Route
INF-PR-01A
0.989
2.264
3.243
4.625
5.648
6.841
22
Pond Route
INF-PR-01B
0.649
1.547
2.338
3.108
4.111
4.967
23
Junction
DET-01A
2.931
5.627
7.742
10.77
13.04
15.60
24
Pond Route
POND-PR-01A
0.408
1.520
2.734
3.984
4.788
8.811
25
Junction
SITE-PR-01A
1.189
2.561
4.231
7.010
8.887
12.15
26
Pond Route
POND-PR-02A
0.248
0.400
0.682
1.196
1.465
2.127
27
Junction
SITE-PR-02A
0.341
0.795
1.251
1.974
2.684
3.536
28
Junction
SITE-PR-DET-A
2.244
5.266
9.355
15.61
20.51
26.11
2

Hydrograph 2-yr Summary
Project Name: Waterford Woods
Hydrology Studio v 3.0.0.16
11-23-2020
Hyd.
No.
Hydrograph
Type
Hydrograph
Name
Peak
Flow
(cfs)
Time to
Peak
(hrs)
Hydrograph
Volume
(cuft)
Inflow
Hyd(s)
Maximum
Elevation
(ft)
Maximum
Storage
(cuft)
1
NRCS Runoff
EX-01
9.328
12.65
78,149
----
2
NRCS Runoff
PR-01
14.24
12.58
102,734
----
3
NRCS Runoff
SITE-EX-01
1.146
12.60
10,688
----
4
NRCS Runoff
SITE-EX-02
0.299
12.60
2,921
----
5
NRCS Runoff
SITE-EX-03
0.811
12.60
7,918
----
6
Junction
SITE-EX
2.256
12.60
21,526
3, 4, 5
7
NRCS Runoff
SITE-PR-01
4.615
12.33
24,374
----
8
NRCS Runoff
SITE-PR-02
2.798
12.32
14,401
----
9
NRCS Runoff
SITE-PR-03
0.811
12.60
7,918
----
10
Junction
SITE-PR
7.916
12.35
46,693
7, 8, 9
11
Pond Route
POND-PR-01
0.876
13.13
16,964
7
31.73
9,343
12
Pond Route
POND-PR-02
0.244
14.03
5,059
8
29.01
6,484
13
Junction
SITE-PR-DET
1.578
12.90
29,942
9, 11, 12
14
NRCS Runoff
PR-01A
0.311
12.38
2,192
----
15
NRCS Runoff
POND-01A
2.095
12.32
10,595
----
16
NRCS Runoff
INF-01A
1.375
12.27
6,727
----
17
NRCS Runoff
INF-01B
1.803
12.10
5,800
----
18
NRCS Runoff
PR-02A
0.229
12.38
1,635
----
19
NRCS Runoff
POND-02A
2.818
12.30
13,788
----
20
NRCS Runoff
PR-03A
0.810
12.60
7,913
----
21
Pond Route
INF-PR-01A
0.989
12.48
5,543
16
31.36
886
22
Pond Route
INF-PR-01B
0.649
12.37
3,637
17
29.78
1,723
23
Junction
DET-01A
2.931
12.35
16,138
15, 21
24
Pond Route
POND-PR-01A
0.408
13.55
9,761
23
31.28
6,936
25
Junction
SITE-PR-01A
1.189
12.42
15,591
14, 22, 24
26
Pond Route
POND-PR-02A
0.248
13.57
4,647
19
29.02
6,568
27
Junction
SITE-PR-02A
0.341
12.55
6,282
18, 26
28
Junction
SITE-PR-DET-A
2.244
12.52
29,786
20, 25, 27
3

Hydrograph 5-yr Summary
Project Name: Waterford Woods
Hydrology Studio v 3.0.0.16
11-23-2020
Hyd.
No.
Hydrograph
Type
Hydrograph
Name
Peak
Flow
(cfs)
Time to
Peak
(hrs)
Hydrograph
Volume
(cuft)
Inflow
Hyd(s)
Maximum
Elevation
(ft)
Maximum
Storage
(cuft)
1
NRCS Runoff
EX-01
20.10
12.58
143,800
----
2
NRCS Runoff
PR-01
27.12
12.53
177,649
----
3
NRCS Runoff
SITE-EX-01
3.092
12.52
21,793
----
4
NRCS Runoff
SITE-EX-02
0.861
12.50
6,121
----
5
NRCS Runoff
SITE-EX-03
2.335
12.50
16,594
----
6
Junction
SITE-EX
6.287
12.50
44,508
3, 4, 5
7
NRCS Runoff
SITE-PR-01
7.896
12.32
39,644
----
8
NRCS Runoff
SITE-PR-02
4.623
12.30
22,903
----
9
NRCS Runoff
SITE-PR-03
2.335
12.50
16,594
----
10
Junction
SITE-PR
14.44
12.33
79,141
7, 8, 9
11
Pond Route
POND-PR-01
2.949
12.75
31,323
7
32.36
13,589
12
Pond Route
POND-PR-02
0.429
13.97
11,988
8
29.69
10,916
13
Junction
SITE-PR-DET
5.355
12.62
59,905
9, 11, 12
14
NRCS Runoff
PR-01A
0.799
12.28
4,343
----
15
NRCS Runoff
POND-01A
3.372
12.30
16,555
----
16
NRCS Runoff
INF-01A
2.397
12.25
11,054
----
17
NRCS Runoff
INF-01B
2.618
12.10
8,423
----
18
NRCS Runoff
PR-02A
0.594
12.28
3,256
----
19
NRCS Runoff
POND-02A
4.247
12.28
20,551
----
20
NRCS Runoff
PR-03A
2.334
12.50
16,584
----
21
Pond Route
INF-PR-01A
2.264
12.32
9,785
16
31.74
1,117
22
Pond Route
INF-PR-01B
1.547
12.22
6,006
17
30.17
2,129
23
Junction
DET-01A
5.627
12.32
26,340
15, 21
24
Pond Route
POND-PR-01A
1.520
12.90
18,916
23
31.92
10,355
25
Junction
SITE-PR-01A
2.561
12.23
29,265
14, 22, 24
26
Pond Route
POND-PR-02A
0.400
13.55
9,917
19
29.58
10,160
27
Junction
SITE-PR-02A
0.795
12.38
13,173
18, 26
28
Junction
SITE-PR-DET-A
5.266
12.38
59,022
20, 25, 27
4

Hydrograph 10-yr Summary
Project Name: Waterford Woods
Hydrology Studio v 3.0.0.16
11-23-2020
Hyd.
No.
Hydrograph
Type
Hydrograph
Name
Peak
Flow
(cfs)
Time to
Peak
(hrs)
Hydrograph
Volume
(cuft)
Inflow
Hyd(s)
Maximum
Elevation
(ft)
Maximum
Storage
(cuft)
1
NRCS Runoff
EX-01
30.75
12.55
207,139
----
2
NRCS Runoff
PR-01
39.27
12.50
247,960
----
3
NRCS Runoff
SITE-EX-01
5.196
12.47
32,965
----
4
NRCS Runoff
SITE-EX-02
1.486
12.45
9,376
----
5
NRCS Runoff
SITE-EX-03
4.028
12.45
25,418
----
6
Junction
SITE-EX
10.71
12.47
67,759
3, 4, 5
7
NRCS Runoff
SITE-PR-01
10.88
12.30
53,568
----
8
NRCS Runoff
SITE-PR-02
6.259
12.30
30,571
----
9
NRCS Runoff
SITE-PR-03
4.028
12.45
25,418
----
10
Junction
SITE-PR
20.72
12.32
109,557
7, 8, 9
11
Pond Route
POND-PR-01
4.132
12.73
44,502
7
32.97
18,290
12
Pond Route
POND-PR-02
0.871
13.23
18,648
8
30.15
14,239
13
Junction
SITE-PR-DET
8.228
12.57
88,568
9, 11, 12
14
NRCS Runoff
PR-01A
1.318
12.25
6,482
----
15
NRCS Runoff
POND-01A
4.502
12.30
21,884
----
16
NRCS Runoff
INF-01A
3.326
12.23
15,020
----
17
NRCS Runoff
INF-01B
3.307
12.10
10,684
----
18
NRCS Runoff
PR-02A
0.986
12.25
4,872
----
19
NRCS Runoff
POND-02A
5.481
12.28
26,457
----
20
NRCS Runoff
PR-03A
4.025
12.45
25,403
----
21
Pond Route
INF-PR-01A
3.243
12.28
13,684
16
31.93
1,226
22
Pond Route
INF-PR-01B
2.338
12.18
8,132
17
30.46
2,408
23
Junction
DET-01A
7.742
12.28
35,568
15, 21
24
Pond Route
POND-PR-01A
2.734
12.73
27,524
23
32.28
12,946
25
Junction
SITE-PR-01A
4.231
12.52
42,138
14, 22, 24
26
Pond Route
POND-PR-02A
0.682
13.20
14,808
19
30.02
13,080
27
Junction
SITE-PR-02A
1.251
12.32
19,680
18, 26
28
Junction
SITE-PR-DET-A
9.355
12.45
87,221
20, 25, 27
5

Hydrograph 25-yr Summary
Project Name: Waterford Woods
Hydrology Studio v 3.0.0.16
11-23-2020
Hyd.
No.
Hydrograph
Type
Hydrograph
Name
Peak
Flow
(cfs)
Time to
Peak
(hrs)
Hydrograph
Volume
(cuft)
Inflow
Hyd(s)
Maximum
Elevation
(ft)
Maximum
Storage
(cuft)
1
NRCS Runoff
EX-01
47.38
12.52
305,899
----
2
NRCS Runoff
PR-01
57.79
12.48
355,425
----
3
NRCS Runoff
SITE-EX-01
8.632
12.43
50,903
----
4
NRCS Runoff
SITE-EX-02
2.519
12.42
14,640
----
5
NRCS Runoff
SITE-EX-03
6.830
12.42
39,689
----
6
Junction
SITE-EX
17.98
12.42
105,232
3, 4, 5
7
NRCS Runoff
SITE-PR-01
15.31
12.30
74,402
----
8
NRCS Runoff
SITE-PR-02
8.663
12.28
41,952
----
9
NRCS Runoff
SITE-PR-03
6.830
12.42
39,689
----
10
Junction
SITE-PR
30.34
12.32
156,043
7, 8, 9
11
Pond Route
POND-PR-01
8.795
12.60
64,406
7
33.72
24,041
12
Pond Route
POND-PR-02
1.410
13.07
28,854
8
30.73
19,479
13
Junction
SITE-PR-DET
15.96
12.58
132,948
9, 11, 12
14
NRCS Runoff
PR-01A
2.155
12.23
9,891
----
15
NRCS Runoff
POND-01A
6.155
12.28
29,741
----
16
NRCS Runoff
INF-01A
4.718
12.23
20,975
----
17
NRCS Runoff
INF-01B
4.283
12.08
13,933
----
18
NRCS Runoff
PR-02A
1.619
12.23
7,450
----
19
NRCS Runoff
POND-02A
7.242
12.28
35,018
----
20
NRCS Runoff
PR-03A
6.826
12.42
39,666
----
21
Pond Route
INF-PR-01A
4.625
12.27
19,554
16
32.18
1,365
22
Pond Route
INF-PR-01B
3.108
12.17
11,227
17
30.90
2,788
23
Junction
DET-01A
10.77
12.28
49,296
15, 21
24
Pond Route
POND-PR-01A
3.984
12.70
40,433
23
32.89
17,616
25
Junction
SITE-PR-01A
7.010
12.32
61,551
14, 22, 24
26
Pond Route
POND-PR-02A
1.196
12.98
22,348
19
30.45
16,991
27
Junction
SITE-PR-02A
1.974
12.25
29,798
18, 26
28
Junction
SITE-PR-DET-A
15.61
12.37
131,015
20, 25, 27
6

Hydrograph 50-yr Summary
Project Name: Waterford Woods
Hydrology Studio v 3.0.0.16
11-23-2020
Hyd.
No.
Hydrograph
Type
Hydrograph
Name
Peak
Flow
(cfs)
Time to
Peak
(hrs)
Hydrograph
Volume
(cuft)
Inflow
Hyd(s)
Maximum
Elevation
(ft)
Maximum
Storage
(cuft)
1
NRCS Runoff
EX-01
60.64
12.52
384,652
----
2
NRCS Runoff
PR-01
72.27
12.48
439,881
----
3
NRCS Runoff
SITE-EX-01
11.45
12.42
65,512
----
4
NRCS Runoff
SITE-EX-02
3.372
12.40
18,948
----
5
NRCS Runoff
SITE-EX-03
9.141
12.40
51,370
----
6
Junction
SITE-EX
23.95
12.40
135,830
3, 4, 5
7
NRCS Runoff
SITE-PR-01
18.70
12.28
90,521
----
8
NRCS Runoff
SITE-PR-02
10.50
12.28
50,705
----
9
NRCS Runoff
SITE-PR-03
9.141
12.40
51,370
----
10
Junction
SITE-PR
37.82
12.32
192,596
7, 8, 9
11
Pond Route
POND-PR-01
11.56
12.58
79,959
7
34.09
27,053
12
Pond Route
POND-PR-02
2.138
12.93
36,806
8
31.17
23,423
13
Junction
SITE-PR-DET
21.30
12.52
168,134
9, 11, 12
14
NRCS Runoff
PR-01A
2.832
12.23
12,652
----
15
NRCS Runoff
POND-01A
7.407
12.28
35,756
----
16
NRCS Runoff
INF-01A
5.787
12.23
25,595
----
17
NRCS Runoff
INF-01B
5.006
12.08
16,372
----
18
NRCS Runoff
PR-02A
2.131
12.23
9,540
----
19
NRCS Runoff
POND-02A
8.554
12.28
41,490
----
20
NRCS Runoff
PR-03A
9.135
12.40
51,339
----
21
Pond Route
INF-PR-01A
5.648
12.27
24,117
16
32.42
1,492
22
Pond Route
INF-PR-01B
4.111
12.15
13,567
17
31.23
2,998
23
Junction
DET-01A
13.04
12.28
59,874
15, 21
24
Pond Route
POND-PR-01A
4.788
12.70
50,437
23
33.39
21,523
25
Junction
SITE-PR-01A
8.887
12.30
76,655
14, 22, 24
26
Pond Route
POND-PR-02A
1.465
12.97
28,104
19
30.81
20,179
27
Junction
SITE-PR-02A
2.684
12.37
37,644
18, 26
28
Junction
SITE-PR-DET-A
20.51
12.37
165,639
20, 25, 27
7

Hydrograph 100-yr Summary
Project Name: Waterford Woods
Hydrology Studio v 3.0.0.16
11-23-2020
Hyd.
No.
Hydrograph
Type
Hydrograph
Name
Peak
Flow
(cfs)
Time to
Peak
(hrs)
Hydrograph
Volume
(cuft)
Inflow
Hyd(s)
Maximum
Elevation
(ft)
Maximum
Storage
(cuft)
1
NRCS Runoff
EX-01
75.64
12.50
474,030
----
2
NRCS Runoff
PR-01
88.49
12.47
534,803
----
3
NRCS Runoff
SITE-EX-01
14.69
12.40
82,325
----
4
NRCS Runoff
SITE-EX-02
4.359
12.38
23,924
----
5
NRCS Runoff
SITE-EX-03
11.82
12.38
64,858
----
6
Junction
SITE-EX
30.85
12.38
171,106
3, 4, 5
7
NRCS Runoff
SITE-PR-01
22.46
12.28
108,450
----
8
NRCS Runoff
SITE-PR-02
12.51
12.28
60,403
----
9
NRCS Runoff
SITE-PR-03
11.82
12.38
64,858
----
10
Junction
SITE-PR
46.19
12.30
233,711
7, 8, 9
11
Pond Route
POND-PR-01
16.47
12.52
97,355
7
34.38
29,751
12
Pond Route
POND-PR-02
3.570
12.78
45,838
8
31.54
26,759
13
Junction
SITE-PR-DET
29.90
12.52
208,050
9, 11, 12
14
NRCS Runoff
PR-01A
3.607
12.22
15,818
----
15
NRCS Runoff
POND-01A
8.776
12.28
42,399
----
16
NRCS Runoff
INF-01A
6.966
12.23
30,743
----
17
NRCS Runoff
INF-01B
5.786
12.08
19,033
----
18
NRCS Runoff
PR-02A
2.719
12.22
11,939
----
19
NRCS Runoff
POND-02A
9.976
12.28
48,578
----
20
NRCS Runoff
PR-03A
11.81
12.38
64,819
----
21
Pond Route
INF-PR-01A
6.841
12.27
29,206
16
32.83
1,671
22
Pond Route
INF-PR-01B
4.967
12.15
16,133
17
31.48
3,145
23
Junction
DET-01A
15.60
12.27
71,606
15, 21
24
Pond Route
POND-PR-01A
8.811
12.57
61,634
23
33.72
24,048
25
Junction
SITE-PR-01A
12.15
12.53
93,584
14, 22, 24
26
Pond Route
POND-PR-02A
2.127
12.87
34,493
19
31.17
23,394
27
Junction
SITE-PR-02A
3.536
12.30
46,432
18, 26
28
Junction
SITE-PR-DET-A
26.11
12.50
204,835
20, 25, 27
8


 
 
 
WATERFORD WOODS APARTMENTS 
 
384 & 394 WILLETTS AVENUE EXT. 
 
WATERFORD, CONNECTICUT 
 
 
 
 
 
 
APPENDIX C 
STORMWATER TREATMENT CALCULATIONS 
Proposed Area 01A-1 
Proposed Area 01A-2 
Proposed Area 01A-3 
Proposed Area 01-B-1 
Proposed Area 02A-1 
Groundwater Recharge Calculations  
 


Yantic River Consultants, LLC
Waterford Woods
Waterford, CT
WQV = Water Quality Volume (acre-feet)
R = Volumetric Runoff Coefficient, 0.050 + 0.009(I)
I = Percent Impervious Cover, Impervious Area / Total Area
DA = Drainage Area (Acres)
DA = 
1.674
acres
IA = Impervious Area (Acres)
IA = 
0.505
acres
I = 
30%
R = 
0.32
WQV = 
0.045
acre-feet
Q = Runoff Depth (in watershed inches)
WQV = Water Quality Volume (acre-feet)
DA = Drainage Area (acres)
Q(in) = 
0.32
watershed inches
Q(in) = 
0.32
watershed inches
P = 
1
in
CN = 
90
Ia = 
0.222
inches
Tc = 
0.33
hours
Ia/P = 
0.222
qu = 
440
csm/in
WQF = Water Quality Flow (cfs)
qu = unit peak discharge (cfs/mi2/inch)
DA = drainage area (mi2)
Q(in) = runoff depth (watershed inches)
WQF = 
0.370
cfs
Determine NCRS Curve Number (CN)
From Appendix B, Figure 2-1 of the 2004 Connecticut Stormwater Manual
From Appendix B, Exhibit 4-111 of the 2004 Connecticut Stormwater Manual
Compute Water Quality Flow
Determine Initial Abstraction (Ia)
From Appendix B, Table 4-1 of the 2004 Connecticut Stormwater Manual
Determine Unit Peak Discharge (qu)
Time of Concentration (Tc), referenced from Pipe Flow Calculation Worksheet
Compute Runoff Depth
STORMWATER TREATMENT CALCULATIONS [AREA 01A-1]
Compute Water Quality Volume
Determine Percent Impervious Cover (I)
Calculate Volumetric Runoff Coefficient (R)
Calculate Water Quality Volume
12
)
"
1
(
A
R
WQV
×
×
=
DA
WQV
Q in
)
12
(
)
(
×
=
)
(in
u
Q
DA
q
WQF
×
×
=
 11/18/20



Return to Outlet Treatment Summary

Yantic River Consultants, LLC
Waterford Woods
Waterford, CT
WQV = Water Quality Volume (acre-feet)
R = Volumetric Runoff Coefficient, 0.050 + 0.009(I)
I = Percent Impervious Cover, Impervious Area / Total Area
DA = Drainage Area (Acres)
DA = 
2.556
acres
IA = Impervious Area (Acres)
IA = 
0.658
acres
I = 
26%
R = 
0.28
WQV = 
0.060
acre-feet
Q = Runoff Depth (in watershed inches)
WQV = Water Quality Volume (acre-feet)
DA = Drainage Area (acres)
Q(in) = 
0.28
watershed inches
Q(in) = 
0.28
watershed inches
P = 
1
in
CN = 
88
Ia = 
0.273
inches
Tc = 
0.30
hours
Ia/P = 
0.273
qu = 
440
csm/in
WQF = Water Quality Flow (cfs)
qu = unit peak discharge (cfs/mi2/inch)
DA = drainage area (mi2)
Q(in) = runoff depth (watershed inches)
WQF = 
0.495
cfs
Compute Runoff Depth
STORMWATER TREATMENT CALCULATIONS [AREA 01A-2]
Compute Water Quality Volume
Determine Percent Impervious Cover (I)
Calculate Volumetric Runoff Coefficient (R)
Calculate Water Quality Volume
Determine NCRS Curve Number (CN)
From Appendix B, Figure 2-1 of the 2004 Connecticut Stormwater Manual
From Appendix B, Exhibit 4-111 of the 2004 Connecticut Stormwater Manual
Compute Water Quality Flow
Determine Initial Abstraction (Ia)
From Appendix B, Table 4-1 of the 2004 Connecticut Stormwater Manual
Determine Unit Peak Discharge (qu)
Time of Concentration (Tc), referenced from Pipe Flow Calculation Worksheet
12
)
"
1
(
A
R
WQV
×
×
=
DA
WQV
Q in
)
12
(
)
(
×
=
)
(in
u
Q
DA
q
WQF
×
×
=
 11/18/20



Return to Outlet Treatment Summary

Yantic River Consultants, LLC
Waterford Woods
Waterford, CT
WQV = Water Quality Volume (acre-feet)
R = Volumetric Runoff Coefficient, 0.050 + 0.009(I)
I = Percent Impervious Cover, Impervious Area / Total Area
DA = Drainage Area (Acres)
DA = 
0.280
acres
IA = Impervious Area (Acres)
IA = 
0.135
acres
I = 
48%
R = 
0.48
WQV = 
0.011
acre-feet
Q = Runoff Depth (in watershed inches)
WQV = Water Quality Volume (acre-feet)
DA = Drainage Area (acres)
Q(in) = 
0.48
watershed inches
Q(in) = 
0.48
watershed inches
P = 
1
in
CN = 
93
Ia = 
0.151
inches
Tc = 
0.13
hours
Ia/P = 
0.151
qu = 
600
csm/in
WQF = Water Quality Flow (cfs)
qu = unit peak discharge (cfs/mi2/inch)
DA = drainage area (mi2)
Q(in) = runoff depth (watershed inches)
WQF = 
0.127
cfs
Compute Runoff Depth
STORMWATER TREATMENT CALCULATIONS [AREA 01A-3]
Compute Water Quality Volume
Determine Percent Impervious Cover (I)
Calculate Volumetric Runoff Coefficient (R)
Calculate Water Quality Volume
Determine NCRS Curve Number (CN)
From Appendix B, Fi