| Traditionally, stormwater detention has been designed and constructed
primarily to mitigate potential flooding impacts. In today’s
urban environment, however, a detention facility can serve several
other purposes, including water pollution control and reduction
of discharge loadings on existing undersized combined sewers, and
as a wetlands mitigation site.
We have written a detailed paper that focuses on planning and management
issues associated with the design of detention ponds in urban environments
and includes a case study. The case study is a recent proposed operation
and maintenance facility for Hudson-Bergen Light Rail Transit System
in Jersey City, New Jersey. The site is mostly open land used primarily
as a railroad yard with other industrial and rail facilities. Being
near a tidal waterway and at the foot of a sloping watershed, the
site is exposed to two flooding sources. Non-point source pollution
generated on-site and off-site required the implementation of water
pollution control measures. The substantially undersized combined
sewer system serving the area and the existing city streets downstream
imposed the need to mitigate existing drainage system deficiencies.
A proposed stormwater collection system, including a storm detention
impoundment system and control structures, would provide environmental
safeguards and has won the approvals and permits granted by state
and municipal agencies.
Lessons learned during the design of the impoundment system—including
dam, siphon and flow control structures, water quality control structures
and new wetlands—are reviewed and discussed in the paper.
The experience gained and conclusions obtained from the case study
are also presented. They will be useful to the engineer, planner,
developer, and public agencies in the planning and design of stormwater
management systems and application of best management practices
to facilitate site development in environmentally stressed urban
areas.
Please call us or send an e-mail if you would like more information
on using stormwater detention in an urban environment.
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