| GI | Basin Bottom | Storage Volume Retained up to the Lowest Outfall Elevation | Impervious Area (AC) |
|---|---|---|---|
| Bioretention Basin 1A | 90.00 | 1,500 cu-ft | 0.40 |
| Bioretention Basin 2A | 94.30 | 47 cu-ft | 0.0 |
| Bioretention Basin 3A | 93.30 | 99 cu-ft | 0.0 |
| Subsurface Infiltration Basin 1 | 87.00 | 980 cu-ft | 0.40 |
| Surface Infiltration Basin 2 | 91.65 | 1,902 cu-ft | 0.19 |
| Surface Infiltration Basin 3 | 90.75 | 2,300 cu-ft | 0.20 |
In accordance with N.J.A.C. 7:8-5.2(h) whenever the stormwater management design includes one or more BMPs that will infiltrate stormwater into subsoil, the design engineer shall assess the hydraulic impact on the groundwater table and design the site, to avoid adverse hydraulic impacts.
A groundwater mounding analysis has been prepared for the proposed green infrastructures (GI) using the USGS Hantush spreadsheet in accordance with NJDEP BMP Manual Chapter 13. The proposed GI's have been modeled using infiltration for all storm events. Therefore, the groundwater mounding analysis has been performed for the infiltration volume generated by the future 100-year storm event as calculated by HydroCAD.
| GROUNDWATER MOUNDING MODELING CRITERIA | ||
| Criteria | Value | Notes |
|---|---|---|
| R-Recharge Rate | See below | Per Geotech |
| Sy-Specific Yield | 0.15 | Default |
| Kh-Horizontal conductivity | 5xR | Coastal Plains |
| hi-Initial Thickness of saturated zone | 34 feet | Per Deep Boring Report |
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