Due to ever-increasing development, green space is continually being eliminated to allow for new construction projects. These projects can significantly increase the amount of runoff produced during rainfall events. As such, it is critical that new developments account for the increased runoff created by the impervious area. This increase in runoff in the watershed or drainage basin can sometimes result in downstream flooding. As a result most local design criteria, require these developments to store a portion of the “post-development” runoff in on-site storage facilities.
Storm Water Management
There are numerous methods to increase on-site storage; the most obvious being detention basins. Detention basins can be sized to handle a variety of return interval storms (i.e. 1-yr, 5-yr, 25-yr, etc.). Of course, land is a valuable asset and must be used wisely. As such unique approaches are called for to maximize on-site detention storage.
Our staff has significant experience performing the required drainage analysis to size on-site detention facilities based on local design criteria. In an effort to alleviate downstream flooding, our firm has made various recommendations leading to the designs of retention/detention basins with overflow weirs, underground storage, existing weir structure modifications, and recommendations for the removal of repeatedly flooded structures.
Our staff has considerable experience with these types of projects and has assisted clients with the development of:
• Site maps showing topography, drainage areas, discharge structures and outfalls, paved areas and buildings, and storage areas
• Estimates of impervious surfaces and total area drained by each outfall
• Designs of stormwater retention basins based upon pre vs. post development conditions
• Storm Drain reports utilizing computer modeling, HEC-RAS, HEC-HMS, SWMM, etc
Storm Water Prevention Pollution Plans
The National Pollutant Discharge Elimination System (NPDES) Stormwater Program regulates stormwater discharges from three potential sources: municipal separate storm sewer systems (MS4s), construction activities, and industrial activities. Most stormwater discharges are considered point sources, and operators of these sources may be required to receive an NPDES permit before they can discharge. This permitting mechanism is designed to prevent stormwater runoff from washing harmful pollutants into local surface waters such as streams, rivers, lakes or coastal waters.
We are dedicated to protecting the environment and providing a balance between land development and environmental impacts. As a result, our staff has extensive experience preparing Storm Water Pollution Prevention Plans (SWPPPs) nationwide for both public and private entities. From filing the initial Notice of Intent to the Notice of Termination, we work to make sure you stay in compliance and avoid costly fines. Our professionals work with you to determine all local, state and federal requirements pertaining to your project and develop a plan to comply. Recognizing that it is essential that all involved parties understand the importance of the SWPPP, we offer pre-construction certification of BMPs and post-construction inspections prior to filing the Notice of Termination.