In support of the proposed development, the existing and proposed hydrology was modeled using HydroCAD software. The drainage areas were delineated based on their hydrological and hydraulic characteristics. The maximum sheet flow time of concentrations are based on McCuen-Spiess criteria.
MODELING CRITERIA
Method: TR-55
Unit Hydrograph: Delmarva
Storm Distribution: D
Rainfall Source: NOAA Atlas 14
2-year Rainfall: 3.42 in.
10-year Rainfall: 5.33 in.
25-year Rainfall: 6.68 in.
100-year Rainfall: 9.20 in.
The rainfall has been adjusted to account for current and future precipitation adjustment factors as required by NJAC 7:8-5.7(c)/(d)
| Current Adjusted | Future Adjusted | ||||
| Rainfall | Adj. Factor | Adj. Rainfall | Adj. Factor | Adj. Rainfall | |
|---|---|---|---|---|---|
| 2 Year | 3.42 | 1.00 | 3.42 | 1.18 | 4.04 |
| 10 Year | 5.33 | 1.01 | 5.38 | 1.19 | 6.34 |
| 100 Year | 9.20 | 1.03 | 9.48 | 1.24 | 11.41 |
The existing site runs off untreated and unretained to the adjoining properties and road. The existing points of analysis, drainage areas, and results are summarized in the tables below.
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