Stormwater Management Controls and Requirements
Table 1 Green Infrastructure BMPs for Groundwater Recharge, Stormwater Runoff Quality, and/or Stormwater Runoff Quantity | ||||
|---|---|---|---|---|
Best Management Practice | Stormwater Runoff Quality TSS Removal Rate (percent) | Stormwater Runoff Quantity | Groundwater Recharge | Minimum Separation from Seasonal High Water Table (feet) |
Cistern | 0% | Yes | No | — |
Dry well(a) | 0% | No | Yes | 2 |
Grass swale | 50% or less | No | No | 2(e) 1(f) |
Green roof | 0% | Yes | No | — |
Manufactured treatment device(a)(g) | 50% or 80% | No | No | Dependent upon the device |
Pervious paving system(a) | 80% | Yes | Yes(b) No(c) | 2(b) \1(c) |
Small-scale bioretention basin(a) | 80% or 90% | Yes | Yes(b) No(c) | 2(b) 1(c) |
Small-scale infiltration basin(a) | 80% | Yes | Yes | 2 |
Small-scale sand filter | 80% | Yes | Yes | 2 |
Vegetative filter strip | 60% to 80% | No | No | — |
(Notes corresponding to annotations (a) through (g) are found after Table 3.) |
Table 2 Green Infrastructure BMPs for Stormwater Runoff Quantity (or for Groundwater Recharge and/or Stormwater Runoff Quality with a Waiver or Variance from N.J.A.C. 7:8-5.3) | ||||
|---|---|---|---|---|
Best Management Practice | Stormwater Runoff Quality TSS Removal Rate (percent) | Stormwater Runoff Quantity | Groundwater Recharge | Minimum Separation from Seasonal High Water Table (feet) |
Bioretention system | 80% or 90% | Yes | Yes(b)+nNo(c) | 2(b)+n1(c) |
Infiltration basin | 80% | Yes | Yes | 2 |
Sand filter(b) | 80% | Yes | Yes | 2 |
Standard constructed wetland | 90% | Yes | No | N/A |
Wet pond(d) | 50% to 90% | Yes | No | N/A |
(Notes corresponding to annotations(a) through (g) are found after Table 3.) |
Table 3 BMPs for Groundwater Recharge, Stormwater Runoff Quality, and/or Stormwater Runoff Quantity only with a Waiver or Variance from N.J.A.C. 7:8-5.3 | ||||
|---|---|---|---|---|
Best Management Practice | Stormwater Runoff Quality TSS Removal Rate (percent) | Stormwater Runoff Quantity | Groundwater Recharge | Minimum Separation from Seasonal High Water Table (feet) |
Blue roof | 0% | Yes | No | N/A |
Extended detention basin | 40% to 60% | Yes | No | 1 |
Manufactured treatment device(h) | 50% or 80% | No | No | Dependent upon the device |
Sand filter(c) | 80% | Yes | No | 1 |
Subsurface gravel wetland | 90% | No | No | 1 |
Wet pond | 50% to 90% | Yes | No | N/A |
Notes to Tables 1, 2, and 3: | |
|---|---|
(a) | Subject to the applicable contributory drainage area limitation specified at § 150-25.4P(2); |
(b) | Designed to infiltrate into the subsoil; |
(c) | Designed with underdrains; |
(d) | Designed to maintain at least a 10-foot-wide area of native vegetation along at least 50% of the shoreline and to include a stormwater runoff retention component designed to capture stormwater runoff for beneficial reuse, such as irrigation; |
(e) | Designed with a slope of less than 2%; |
(f) | Designed with a slope of equal to or greater than 2%; |
(g) | Manufactured treatment devices that meet the definition of "green infrastructure" at § 150-25.2; |
(h) | Manufactured treatment devices that do not meet the definition of "green infrastructure" at § 150-25.2. |
Best Management Practice | Maximum Contributory Drainage Area |
|---|---|
Dry well | 1 acre |
Manufactured treatment device | 2.5 acres |
Pervious pavement systems | Area of additional inflow cannot exceed 3 times the area occupied by the BMP |
Small-scale bioretention systems | 2.5 acres |
Small-scale infiltration basin | 2.5 acres |
Small-scale sand filter | 2.5 acres |
Table 4 - Water Quality Design Storm Distribution | |||||
|---|---|---|---|---|---|
Time (minutes) | Cumulative Rainfall (inches) | Time (minutes) | Cumulative Rainfall (inches) | Time (minutes) | Cumulative Rainfall (inches) |
1 | 0.00166 | 41 | 0.1728 | 81 | 1.0906 |
2 | 0.00332 | 42 | 0.1796 | 82 | 1.0972 |
3 | 0.00498 | 43 | 0.1864 | 83 | 1.1038 |
4 | 0.00664 | 44 | 0.1932 | 84 | 1.1104 |
5 | 0.00830 | 45 | 0.2000 | 85 | 1.1170 |
6 | 0.00996 | 46 | 0.2117 | 86 | 1.1236 |
7 | 0.01162 | 47 | 0.2233 | 87 | 1.1302 |
8 | 0.01328 | 48 | 0.2350 | 88 | 1.1368 |
9 | 0.01494 | 49 | 0.2466 | 89 | 1.1434 |
10 | 0.01660 | 50 | 0.2583 | 90 | 1.1500 |
11 | 0.01828 | 51 | 0.2783 | 91 | 1.1550 |
12 | 0.01996 | 52 | 0.2983 | 92 | 1.1600 |
13 | 0.02164 | 53 | 0.3183 | 93 | 1.1650 |
14 | 0.02332 | 54 | 0.3383 | 94 | 1.1700 |
15 | 0.02500 | 55 | 0.3583 | 95 | 1.1750 |
16 | 0.03000 | 56 | 0.4116 | 96 | 1.1800 |
17 | 0.03500 | 57 | 0.4650 | 97 | 1.1850 |
18 | 0.04000 | 58 | 0.5183 | 98 | 1.1900 |
19 | 0.04500 | 59 | 0.5717 | 99 | 1.1950 |
20 | 0.05000 | 60 | 0.6250 | 100 | 1.2000 |
21 | 0.05500 | 61 | 0.6783 | 101 | 1.2050 |
22 | 0.06000 | 62 | 0.7317 | 102 | 1.2100 |
23 | 0.06500 | 63 | 0.7850 | 103 | 1.2150 |
24 | 0.07000 | 64 | 0.8384 | 104 | 1.2200 |
25 | 0.07500 | 65 | 0.8917 | 105 | 1.2250 |
26 | 0.08000 | 66 | 0.9117 | 106 | 1.2267 |
27 | 0.08500 | 67 | 0.9317 | 107 | 1.2284 |
28 | 0.09000 | 68 | 0.9517 | 108 | 1.2300 |
29 | 0.09500 | 69 | 0.9717 | 109 | 1.2317 |
30 | 0.10000 | 70 | 0.9917 | 110 | 1.2334 |
31 | 0.10660 | 71 | 1.0034 | 111 | 1.2351 |
32 | 0.11320 | 72 | 1.0150 | 112 | 1.2367 |
33 | 0.11980 | 73 | 1.0267 | 113 | 1.2384 |
34 | 0.12640 | 74 | 1.0383 | 114 | 1.2400 |
35 | 0.13300 | 75 | 1.0500 | 115 | 1.2417 |
36 | 0.13960 | 76 | 1.0568 | 116 | 1.2434 |
37 | 0.14620 | 77 | 1.0636 | 117 | 1.2450 |
38 | 0.15280 | 78 | 1.0704 | 118 | 1.2467 |
39 | 0.15940 | 79 | 1.0772 | 119 | 1.2483 |
40 | 0.16600 | 80 | 1.0840 | 120 | 1.2500 |
R = A + B - (A x B)/100, | ||
Where: | ||
R | = | total TSS percent load removal from application of both BMPs. |
A | = | the TSS percent removal rate applicable to the first BMP. |
B | = | the TSS percent removal rate applicable to the second BMP. |
Table 5: Current Precipitation Adjustment Factors | |||
|---|---|---|---|
County | 2-Year Design Storm | 10-Year Design Storm | 100-Year Design Storm |
Atlantic | 1.01 | 1.02 | 1.03 |
Bergen | 1.01 | 1.03 | 1.06 |
Burlington | 0.99 | 1.01 | 1.04 |
Camden | 1.03 | 1.04 | 1.05 |
Cape May | 1.03 | 1.03 | 1.04 |
Cumberland | 1.03 | 1.03 | 1.01 |
Essex | 1.01 | 1.03 | 1.06 |
Gloucester | 1.05 | 1.06 | 1.06 |
Hudson | 1.03 | 1.05 | 1.09 |
Hunterdon | 1.02 | 1.05 | 1.13 |
Mercer | 1.01 | 1.02 | 1.04 |
Middlesex | 1.00 | 1.01 | 1.03 |
Monmouth | 1.00 | 1.01 | 1.02 |
Morris | 1.01 | 1.03 | 1.06 |
Ocean | 1.00 | 1.01 | 1.03 |
Passaic | 1.00 | 1.02 | 1.05 |
Salem | 1.02 | 1.03 | 1.03 |
Somerset | 1.00 | 1.03 | 1.09 |
Sussex | 1.03 | 1.04 | 1.07 |
Union | 1.01 | 1.03 | 1.06 |
Warren | 1.02 | 1.07 | 1.15 |
Table 6: Future Precipitation Change Factors | |||
|---|---|---|---|
County | 2-Year Design Storm | 10-Year Design Storm | 100-Year Design Storm |
Atlantic | 1.22 | 1.24 | 1.39 |
Bergen | 1.20 | 1.23 | 1.37 |
Burlington | 1.17 | 1.18 | 1.32 |
Camden | 1.18 | 1.22 | 1.39 |
Cape May | 1.21 | 1.24 | 1.32 |
Cumberland | 1.20 | 1.21 | 1.39 |
Essex | 1.19 | 1.22 | 1.33 |
Gloucester | 1.19 | 1.23 | 1.41 |
Hudson | 1.19 | 1.19 | 1.23 |
Hunterdon | 1.19 | 1.23 | 1.42 |
Mercer | 1.16 | 1.17 | 1.36 |
Middlesex | 1.19 | 1.21 | 1.33 |
Monmouth | 1.19 | 1.19 | 1.26 |
Morris | 1.23 | 1.28 | 1.46 |
Ocean | 1.18 | 1.19 | 1.24 |
Passaic | 1.21 | 1.27 | 1.50 |
Salem | 1.20 | 1.23 | 1.32 |
Somerset | 1.19 | 1.24 | 1.48 |
Sussex | 1.24 | 1.29 | 1.50 |
Union | 1.20 | 1.23 | 1.35 |
Warren | 1.20 | 1.25 | 1.37 |
Examples of grates subject to this standard include grates in grate inlets, the grate portion (non-curb-opening portion) of combination inlets, grates on storm sewer manholes, ditch grates, trench grates, and grates of spacer bars in slotted drains. Examples of ground surfaces include surfaces of roads (including bridges), driveways, parking areas, bikeways, plazas, sidewalks, lawns, fields, open channels, and stormwater system floors used to collect stormwater from the surface into a storm drain or surface water body. |
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.) |
Table 8 Rain Garden Table | |||
|---|---|---|---|
Rain Garden Size | |||
Drainage Area (ft2) | Clay Soil (soil amendments needed) (ft2) | Silty Soil (ft2) | Sandy Soil (ft2) |
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.) |
Stormwater Management Controls and Requirements
Table 1 Green Infrastructure BMPs for Groundwater Recharge, Stormwater Runoff Quality, and/or Stormwater Runoff Quantity | ||||
|---|---|---|---|---|
Best Management Practice | Stormwater Runoff Quality TSS Removal Rate (percent) | Stormwater Runoff Quantity | Groundwater Recharge | Minimum Separation from Seasonal High Water Table (feet) |
Cistern | 0% | Yes | No | — |
Dry well(a) | 0% | No | Yes | 2 |
Grass swale | 50% or less | No | No | 2(e) 1(f) |
Green roof | 0% | Yes | No | — |
Manufactured treatment device(a)(g) | 50% or 80% | No | No | Dependent upon the device |
Pervious paving system(a) | 80% | Yes | Yes(b) No(c) | 2(b) \1(c) |
Small-scale bioretention basin(a) | 80% or 90% | Yes | Yes(b) No(c) | 2(b) 1(c) |
Small-scale infiltration basin(a) | 80% | Yes | Yes | 2 |
Small-scale sand filter | 80% | Yes | Yes | 2 |
Vegetative filter strip | 60% to 80% | No | No | — |
(Notes corresponding to annotations (a) through (g) are found after Table 3.) |
Table 2 Green Infrastructure BMPs for Stormwater Runoff Quantity (or for Groundwater Recharge and/or Stormwater Runoff Quality with a Waiver or Variance from N.J.A.C. 7:8-5.3) | ||||
|---|---|---|---|---|
Best Management Practice | Stormwater Runoff Quality TSS Removal Rate (percent) | Stormwater Runoff Quantity | Groundwater Recharge | Minimum Separation from Seasonal High Water Table (feet) |
Bioretention system | 80% or 90% | Yes | Yes(b)+nNo(c) | 2(b)+n1(c) |
Infiltration basin | 80% | Yes | Yes | 2 |
Sand filter(b) | 80% | Yes | Yes | 2 |
Standard constructed wetland | 90% | Yes | No | N/A |
Wet pond(d) | 50% to 90% | Yes | No | N/A |
(Notes corresponding to annotations(a) through (g) are found after Table 3.) |
Table 3 BMPs for Groundwater Recharge, Stormwater Runoff Quality, and/or Stormwater Runoff Quantity only with a Waiver or Variance from N.J.A.C. 7:8-5.3 | ||||
|---|---|---|---|---|
Best Management Practice | Stormwater Runoff Quality TSS Removal Rate (percent) | Stormwater Runoff Quantity | Groundwater Recharge | Minimum Separation from Seasonal High Water Table (feet) |
Blue roof | 0% | Yes | No | N/A |
Extended detention basin | 40% to 60% | Yes | No | 1 |
Manufactured treatment device(h) | 50% or 80% | No | No | Dependent upon the device |
Sand filter(c) | 80% | Yes | No | 1 |
Subsurface gravel wetland | 90% | No | No | 1 |
Wet pond | 50% to 90% | Yes | No | N/A |
Notes to Tables 1, 2, and 3: | |
|---|---|
(a) | Subject to the applicable contributory drainage area limitation specified at § 150-25.4P(2); |
(b) | Designed to infiltrate into the subsoil; |
(c) | Designed with underdrains; |
(d) | Designed to maintain at least a 10-foot-wide area of native vegetation along at least 50% of the shoreline and to include a stormwater runoff retention component designed to capture stormwater runoff for beneficial reuse, such as irrigation; |
(e) | Designed with a slope of less than 2%; |
(f) | Designed with a slope of equal to or greater than 2%; |
(g) | Manufactured treatment devices that meet the definition of "green infrastructure" at § 150-25.2; |
(h) | Manufactured treatment devices that do not meet the definition of "green infrastructure" at § 150-25.2. |
Best Management Practice | Maximum Contributory Drainage Area |
|---|---|
Dry well | 1 acre |
Manufactured treatment device | 2.5 acres |
Pervious pavement systems | Area of additional inflow cannot exceed 3 times the area occupied by the BMP |
Small-scale bioretention systems | 2.5 acres |
Small-scale infiltration basin | 2.5 acres |
Small-scale sand filter | 2.5 acres |
Table 4 - Water Quality Design Storm Distribution | |||||
|---|---|---|---|---|---|
Time (minutes) | Cumulative Rainfall (inches) | Time (minutes) | Cumulative Rainfall (inches) | Time (minutes) | Cumulative Rainfall (inches) |
1 | 0.00166 | 41 | 0.1728 | 81 | 1.0906 |
2 | 0.00332 | 42 | 0.1796 | 82 | 1.0972 |
3 | 0.00498 | 43 | 0.1864 | 83 | 1.1038 |
4 | 0.00664 | 44 | 0.1932 | 84 | 1.1104 |
5 | 0.00830 | 45 | 0.2000 | 85 | 1.1170 |
6 | 0.00996 | 46 | 0.2117 | 86 | 1.1236 |
7 | 0.01162 | 47 | 0.2233 | 87 | 1.1302 |
8 | 0.01328 | 48 | 0.2350 | 88 | 1.1368 |
9 | 0.01494 | 49 | 0.2466 | 89 | 1.1434 |
10 | 0.01660 | 50 | 0.2583 | 90 | 1.1500 |
11 | 0.01828 | 51 | 0.2783 | 91 | 1.1550 |
12 | 0.01996 | 52 | 0.2983 | 92 | 1.1600 |
13 | 0.02164 | 53 | 0.3183 | 93 | 1.1650 |
14 | 0.02332 | 54 | 0.3383 | 94 | 1.1700 |
15 | 0.02500 | 55 | 0.3583 | 95 | 1.1750 |
16 | 0.03000 | 56 | 0.4116 | 96 | 1.1800 |
17 | 0.03500 | 57 | 0.4650 | 97 | 1.1850 |
18 | 0.04000 | 58 | 0.5183 | 98 | 1.1900 |
19 | 0.04500 | 59 | 0.5717 | 99 | 1.1950 |
20 | 0.05000 | 60 | 0.6250 | 100 | 1.2000 |
21 | 0.05500 | 61 | 0.6783 | 101 | 1.2050 |
22 | 0.06000 | 62 | 0.7317 | 102 | 1.2100 |
23 | 0.06500 | 63 | 0.7850 | 103 | 1.2150 |
24 | 0.07000 | 64 | 0.8384 | 104 | 1.2200 |
25 | 0.07500 | 65 | 0.8917 | 105 | 1.2250 |
26 | 0.08000 | 66 | 0.9117 | 106 | 1.2267 |
27 | 0.08500 | 67 | 0.9317 | 107 | 1.2284 |
28 | 0.09000 | 68 | 0.9517 | 108 | 1.2300 |
29 | 0.09500 | 69 | 0.9717 | 109 | 1.2317 |
30 | 0.10000 | 70 | 0.9917 | 110 | 1.2334 |
31 | 0.10660 | 71 | 1.0034 | 111 | 1.2351 |
32 | 0.11320 | 72 | 1.0150 | 112 | 1.2367 |
33 | 0.11980 | 73 | 1.0267 | 113 | 1.2384 |
34 | 0.12640 | 74 | 1.0383 | 114 | 1.2400 |
35 | 0.13300 | 75 | 1.0500 | 115 | 1.2417 |
36 | 0.13960 | 76 | 1.0568 | 116 | 1.2434 |
37 | 0.14620 | 77 | 1.0636 | 117 | 1.2450 |
38 | 0.15280 | 78 | 1.0704 | 118 | 1.2467 |
39 | 0.15940 | 79 | 1.0772 | 119 | 1.2483 |
40 | 0.16600 | 80 | 1.0840 | 120 | 1.2500 |
R = A + B - (A x B)/100, | ||
Where: | ||
R | = | total TSS percent load removal from application of both BMPs. |
A | = | the TSS percent removal rate applicable to the first BMP. |
B | = | the TSS percent removal rate applicable to the second BMP. |
Table 5: Current Precipitation Adjustment Factors | |||
|---|---|---|---|
County | 2-Year Design Storm | 10-Year Design Storm | 100-Year Design Storm |
Atlantic | 1.01 | 1.02 | 1.03 |
Bergen | 1.01 | 1.03 | 1.06 |
Burlington | 0.99 | 1.01 | 1.04 |
Camden | 1.03 | 1.04 | 1.05 |
Cape May | 1.03 | 1.03 | 1.04 |
Cumberland | 1.03 | 1.03 | 1.01 |
Essex | 1.01 | 1.03 | 1.06 |
Gloucester | 1.05 | 1.06 | 1.06 |
Hudson | 1.03 | 1.05 | 1.09 |
Hunterdon | 1.02 | 1.05 | 1.13 |
Mercer | 1.01 | 1.02 | 1.04 |
Middlesex | 1.00 | 1.01 | 1.03 |
Monmouth | 1.00 | 1.01 | 1.02 |
Morris | 1.01 | 1.03 | 1.06 |
Ocean | 1.00 | 1.01 | 1.03 |
Passaic | 1.00 | 1.02 | 1.05 |
Salem | 1.02 | 1.03 | 1.03 |
Somerset | 1.00 | 1.03 | 1.09 |
Sussex | 1.03 | 1.04 | 1.07 |
Union | 1.01 | 1.03 | 1.06 |
Warren | 1.02 | 1.07 | 1.15 |
Table 6: Future Precipitation Change Factors | |||
|---|---|---|---|
County | 2-Year Design Storm | 10-Year Design Storm | 100-Year Design Storm |
Atlantic | 1.22 | 1.24 | 1.39 |
Bergen | 1.20 | 1.23 | 1.37 |
Burlington | 1.17 | 1.18 | 1.32 |
Camden | 1.18 | 1.22 | 1.39 |
Cape May | 1.21 | 1.24 | 1.32 |
Cumberland | 1.20 | 1.21 | 1.39 |
Essex | 1.19 | 1.22 | 1.33 |
Gloucester | 1.19 | 1.23 | 1.41 |
Hudson | 1.19 | 1.19 | 1.23 |
Hunterdon | 1.19 | 1.23 | 1.42 |
Mercer | 1.16 | 1.17 | 1.36 |
Middlesex | 1.19 | 1.21 | 1.33 |
Monmouth | 1.19 | 1.19 | 1.26 |
Morris | 1.23 | 1.28 | 1.46 |
Ocean | 1.18 | 1.19 | 1.24 |
Passaic | 1.21 | 1.27 | 1.50 |
Salem | 1.20 | 1.23 | 1.32 |
Somerset | 1.19 | 1.24 | 1.48 |
Sussex | 1.24 | 1.29 | 1.50 |
Union | 1.20 | 1.23 | 1.35 |
Warren | 1.20 | 1.25 | 1.37 |
Examples of grates subject to this standard include grates in grate inlets, the grate portion (non-curb-opening portion) of combination inlets, grates on storm sewer manholes, ditch grates, trench grates, and grates of spacer bars in slotted drains. Examples of ground surfaces include surfaces of roads (including bridges), driveways, parking areas, bikeways, plazas, sidewalks, lawns, fields, open channels, and stormwater system floors used to collect stormwater from the surface into a storm drain or surface water body. |
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.) |
Table 8 Rain Garden Table | |||
|---|---|---|---|
Rain Garden Size | |||
Drainage Area (ft2) | Clay Soil (soil amendments needed) (ft2) | Silty Soil (ft2) | Sandy Soil (ft2) |
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.) |