NTM Engineering developed an Act 167 Stormwater Management Plan for the Philadelphia Water Department (PWD). The Poquessing Creek Watershed, which is located in southeastern Pennsylvania with portions in Philadelphia, Montgomery, and Bucks Counties, encompasses approximately 21.5 square miles. The health of the watershed, its communities, and its many watershed resources, like parks and historical features, are threatened by stormwater issues including, but not limited to, flooding and pollution. The PWD completed a Rivers Conservation Plan that concluded that proper stormwater management to improve water quality should be a priority in the watershed.
The NTM team’s major tasks for this project included data collection and analysis of existing stormwater management facilities and bridges; GIS mapping and data acquisition; technical analysis utilizing the Stormwater Management Model (SWMM) hydrologic model and PWD data; development of criteria and standards for the control of storm runoff; and drafting and submitting the final Act 167 Plan. The product of this contract was a comprehensive, integrated Plan that addressed water quality, infiltration, stormwater volume and peak rate control, stream bank erosion, and flooding.
Because municipal acceptance of the Plan is crucial to its success and long-term implementation, the technical analysis and results were presented in layman’s language for it to become effective. NTM also played a key role in the education process by developing training materials and performing public presentations and training forums.