TABLE B-1
DESIGN STORM RAINFALL AMOUNT
Source: NOAA Atlas 14 website, Doylestown Gage (36-2221)
http://hdsc.nws.noaa.gov/hdsc/pfds/orb/pa_pfds.html
FIGURE B-1
ATLAS 14 TYPE II S-CURVES FOR ALL FREQUENCY STORMS - DOYLESTOWN
GAGE (36-2221)
Source: NOAA Atlas 14 website, Doylestown Gage (36-2221) http://hdsc.nws.noaa.gov/hdsc/pfds/orb/pa_pfds.html.
TABLE B-2
NATURAL RESOURCE PROTECTION STORMWATER MANAGEMENT CONTROLS
Source: PA BMP Manual Chapter 8, pg. 33
TABLE B-3
GUIDANCE TO CALCULATE THE 2-YEAR, 24-HOUR VOLUME INCREASE FROM PRE-DEVELOPMENT TO POST-DEVELOPMENT CONDITIONS
Source: PA BMP Manual Chapter 8, pg. 37
TABLE B-4
RUNOFF CURVE NUMBERS
Source: NRCS (SCS) TR-55
TABLE B-5
VOLUME CONTROL CALCULATION GUIDANCE FOR NONSTRUCTURAL BMPS
Source: PA BMP Manual Chapter 8, pg. 34
TABLE B-6
VOLUME CONTROL CALCULATION GUIDANCE FOR STRUCTURAL BMPS
Source: PA BMP Manual Chapter 8, pg. 38
TABLE B-7
RATIONAL RUNOFF COEFFICIENTS
Source: New Jersey Department of Transportation, Technical Manual for Stream
Encroachment, August, 1984
TABLE B-8
MANNING ROUGHNESS COEFFICIENTS
TABLE B-1
DESIGN STORM RAINFALL AMOUNT (INCHES)
The design storm rainfall amount chosen for design should be obtained from the National Oceanic and Atmospheric Administration Atlas 14 interactive website: http://hdsc.nws.noaa.gov/hdsc/pfds/orb/pa_pfds.html
Source: NOAA Atlas 14 website, Doylestown Gage (36-2221)
http://hdsc.nws.noaa.gov/hdsc/pfds/orb/pa_pfds.html
FIGURE B-1
ATLAS 14 TYPE II S-CURVES FOR ALL FREQUENCY STORMS –
DOYLESTOWN GAGE (36-2221)
TABLE B-2
NATURAL RESOURCE PROTECTION
STORMWATER MANAGEMENT CONTROLS
Existing Natural Sensitive Resource | Mapped in the ERSAP? Yes/No/n/a | Total Area (Ac.) | Area to be Protected (Ac.) |
Existing Natural Sensitive Resource | Mapped in the ERSAP? Yes/No/n/a | Total Area (Ac.) | Area to be Protected (Ac.) |
Floodplains | |||
Natural drainage ways | |||
Other: | |||
Other: | |||
Riparian areas/buffers | |||
Steep slopes, 15% to 25% | |||
Steep slopes, over 25% | |||
Vernal pools | |||
Waterbodies | |||
Wetlands | |||
Woodlands | |||
Total Existing: | |||
TABLE B-3
GUIDANCE TO CALCULATE THE TWO-YEAR, 24-HOUR VOLUME INCREASE
FROM PRE-DEVELOPMENT TO POST-DEVELOPMENT CONDITIONS
Existing Conditions: Cover Type/Condition | Soil Type | Area (sf) | Area (ac) | CN | S | Ia (0.2*S) | Q Runoff (in) | Runoff Volume (ft3) |
Imperious | ||||||||
Meadow | ||||||||
Woodland | ||||||||
Total: |
Developed Conditions: Cover Type/Condition | Soil Type | Area (sf) | Area (ac) | CN | S | Ia (0.2*S) | Q Runoff (in) | Runoff Volume (ft3) |
Impervious | ||||||||
Meadow | ||||||||
Woodland | ||||||||
Total: | ||||||||
2-year Volume Increase (ft3): | ||||||||
TABLE B-4
RUNOFF CURVE NUMBERS (FROM NRCS (SCS) TR-55)
TABLE B-5
VOLUME CONTROL CALCULATION GUIDANCE FOR NONSTRUCTURAL BMPS
TABLE B-6
VOLUME CONTROL CALCULATION GUIDANCE FOR STRUCTURAL BMPS
TABLE B-7
RATIONAL RUNOFF COEFFICIENTS
TABLE B-8
MANNING’S ROUGHNESS COEFFICIENTS
(Ord. 239, passed 10-14-2020)