Small-Scale Infiltration Basins (Table 5-1 – Quantity, Quality, & Recharge)
| Design Criteria | Required | Provided |
|---|---|---|
| Total Drainage Area | -- | Basin A: 0.74 Acres |
| Min. Storage Volume below 1st Orifice (Net Increase of Impervious 10 Year Storm Volume) | Basin A: 0.101 ac-ft | Basin A: 0.392 ac-ft |
| Max. Contributory DA | 2.5 acres | Basin A: 0.787 Acres |
| Max. Drain Time | 72 hours | Basin A: 24.65 hours |
| Separation from SHWT | 2 feet | Basin A: 11.7 feet, additional testing required (SPP-1) |
| Design Permeability Rate | Min. = 0.5 in/hr Max. = 10 in/hr | Basin A: 10 in/hr (SPP-1) |
| Max. Depth of WQ Storm | 2 feet | Basin A: 0.20 ft |
| Pretreatment | 80% TSS Removal BMP upstream of Underground Basin A | Hydro International Up-Flo Filter |
The site has been designed to meet the flow reduction requirements as noted in NJAC 7:8-5.6(b)3. The points of analysis have been identified on the Drainage Area Maps as previously described. Below is a summary table demonstrating compliance with the flow reduction requirements. Peak Flow Reduction Calculations are included within the appendix of this report.
Point of Analysis #1 (Study Area West)
| Storm Event | Existing Peak Flow (CFS) | Required Reduction | Max. Allowable Peak Flow (CFS) | Proposed Peak Flow (CFS) |
|---|---|---|---|---|
| 2-Year Current | 0.25 | 0.50 | 0.125 | 0.00 |
| 2- Year Projected | 0.23 | 0.50 | 0.115 | 0.00 |
| 10-Year Current | 0.41 | 0.25 | 0.225 | 0.01 |
| 10- Year Projected | 0.45 | 0.25 | 0.338 | 0.04 |
| 100-Year Current | 1.81 | 0.20 | 1.208 | 0.88 |
| 100- Year Projected | 2.37 | 0.20 | 1.896 | 1.27 |