Design and Improvement Standards
Q | = | AIR | |
Where: | |||
Q | = | The required capacity in cubic feet per second for the collection system at the point of design. | |
A | = | The tributary drainage area in acres and shall include areas tributary from outside sources as well as from within the subdivision itself. | |
I | = | The rainfall intensity in inches per hour and shall be determined from Rainfall Intensity Duration Curves for New Jersey as prepared by the New Jersey Department of Transportation. | |
R | = | The coefficient of runoff applicable to the area based upon soil conditions, average slope of the area and degree of ultimate area development. In no case shall "R" = less than 0.30. | |
Land Use Type | Runoff Coefficients |
|---|---|
Business: | |
Downtown areas | 0.70 to 0.95 |
Neighborhood areas | 0.50 to 0.70 |
Design commercial centers | 0.35 to 0.50 |
Residential: | |
Single-family areas | 0.30 to 0.95 |
Multifamily units | 0.60 to 0.75 |
Residential (suburban) | 0.25 to 0.40 |
Planned industrial | 0.50 to 0.80 |
Parks; cemeteries | 0.10 to 0.25 |
Playgrounds | 0.20 to 0.35 |
Unimproved areas | 0.10 to 0.30 |
Surface Type | Runoff Coefficients |
|---|---|
Streets: | |
Asphalt | 0.70 to 0.95 |
Concrete | 0.80 to 0.95 |
Drives and walks | 0.75 to 0.85 |
Roofs | 0.75 to 0.95 |
Lawns; sandy soil: | 0.05 to 0.10 |
Flat, 2% to 7% grade | 0.10 to 0.15 |
Average, 2% to 7% grade | 0.10 to 0.15 |
NEW JERSEY TWENTY-FOUR-HOUR RAINFALL | |||||||
|---|---|---|---|---|---|---|---|
County | 1-Year | 2-Year | 5-Year | 10-Year | 35-Year | 50-Year | 100-Year |
Atlantic | 2.8 | 3.5 | 4.5 | 5.5 | 6.2 | 6.8 | 7.6 |
Design and Improvement Standards
Q | = | AIR | |
Where: | |||
Q | = | The required capacity in cubic feet per second for the collection system at the point of design. | |
A | = | The tributary drainage area in acres and shall include areas tributary from outside sources as well as from within the subdivision itself. | |
I | = | The rainfall intensity in inches per hour and shall be determined from Rainfall Intensity Duration Curves for New Jersey as prepared by the New Jersey Department of Transportation. | |
R | = | The coefficient of runoff applicable to the area based upon soil conditions, average slope of the area and degree of ultimate area development. In no case shall "R" = less than 0.30. | |
Land Use Type | Runoff Coefficients |
|---|---|
Business: | |
Downtown areas | 0.70 to 0.95 |
Neighborhood areas | 0.50 to 0.70 |
Design commercial centers | 0.35 to 0.50 |
Residential: | |
Single-family areas | 0.30 to 0.95 |
Multifamily units | 0.60 to 0.75 |
Residential (suburban) | 0.25 to 0.40 |
Planned industrial | 0.50 to 0.80 |
Parks; cemeteries | 0.10 to 0.25 |
Playgrounds | 0.20 to 0.35 |
Unimproved areas | 0.10 to 0.30 |
Surface Type | Runoff Coefficients |
|---|---|
Streets: | |
Asphalt | 0.70 to 0.95 |
Concrete | 0.80 to 0.95 |
Drives and walks | 0.75 to 0.85 |
Roofs | 0.75 to 0.95 |
Lawns; sandy soil: | 0.05 to 0.10 |
Flat, 2% to 7% grade | 0.10 to 0.15 |
Average, 2% to 7% grade | 0.10 to 0.15 |
NEW JERSEY TWENTY-FOUR-HOUR RAINFALL | |||||||
|---|---|---|---|---|---|---|---|
County | 1-Year | 2-Year | 5-Year | 10-Year | 35-Year | 50-Year | 100-Year |
Atlantic | 2.8 | 3.5 | 4.5 | 5.5 | 6.2 | 6.8 | 7.6 |