West Orange City Zoning Code
§ 25-29.9
Stormwater Management Requirement for Minor Development.
[Added 5-20-2025 by Ord. No. 2918-25]
a.
The stormwater runoff requirements applicable to minor developments are as follows:
1.
For each square foot of increased impervious surface, six inches per square foot of stormwater shall be managed using green infrastructure practices set out in Table 7 below or such other measures as may be required by the Municipal Engineer of which the retention storm must be retained on-site using green infrastructure.
2.
All such development shall be subject to review by the Municipal Engineer to determine that all stormwater runoff created by the development is adequately controlled in accordance with the standards of this section.
3.
In such cases where it is determined that the outflow from the stormwater management system will impact an adjacent property, the outflow shall be directed to a storm sewer, swale, or other suitable stormwater runoff conveyance measure.
4.
If the Municipal Engineer determines that the outflow from the stormwater management system may potentially damage an adjoining property and the outflow cannot be safely directed to a storm sewer, swale, or other suitable stormwater runoff conveyance measure, the stormwater runoff from the development shall be retained on-site at a rate of four inches of storage for each square foot of new impervious surface using green infrastructure practices or such other measures as may be required by the Municipal Engineer.
5.
If the applicant cannot comply with § 25-29.9a above, the proposal should be redesigned or reduced in scope so that the stormwater management measures do not damage an adjoining property.
Table 7: Minor Development BMP | |
|---|---|
Grass swale | Green roof |
Pervious paving system | Small-scale bioretention basin |
Small-scale infiltration basin | Small-scale sand filter |
Vegetative filter strip | Cistern |
Dry well* | |
(*The use of dry wells is allowed only where the other listed methods cannot feasibly meet the requirements of this section.)
6.
Table 8 provides presumptive rain garden sizes that can be installed to manage New Jersey's water quality design storm on minor developments.
Table 8: Rain Garden Table | |||
|---|---|---|---|
Drainage Area (square feet) | Rain Garden Size (square feet) | ||
Clay Soil (soil amendments needed) | Silty Soil | Sandy Soil | |
500 | 200 | 100 | 75 |
750 | 350 | 150 | 112 |
1,000 | 400 | 200 | 149 |
1,500 | 600 | 300 | 224 |
2,000 | 800 | 400 | 299 |
(Source: Rain Garden Manual of New Jersey, Rutgers Water Resource Programs. Rain garden size based on New Jersey's water quality design storm - 1.25 inches of rain over two hours.)
7.
The stormwater management feature shall be protected from future development by conservation easement, deed restriction, or other acceptable measures.
8.
Waivers. A waiver from strict compliance with § 25-29.9 may be granted by the Township Engineer for those projects where an applicant has demonstrated the inability or impracticability of strictest compliance with the stormwater management requirements in that section. No waiver shall be granted if the runoff compliance is less than the ten-year rainfall event.
9.
The use of a BMP is subject to soil suitability and approval of the Township Engineer.
