After years of sediment build-up in the Northeast Branch of the Nissequogue River, groundwater flooding was becoming a regular occurrence for some local Smithtown residents. The sediment build-up was due to neighborhood street and stormwater drainage systems; these deposits resulted in pipe flow restrictions and a limitation on the ability of the stream to handle the rain water volumes.
The Town of Smithtown decided to do something about it, hiring H2M to assist in restoring stream flow capacity. Through the use of hydraulic de-silting and de-snagging methods, our engineers were able to improve the stream’s ability to convey excess groundwater and stormwater away from residences in the adjacent neighborhoods.
We developed a plan for nearly 3,000 feet of the river, which involved removing deposited sediment from the stream channel while minimizing disruption to existing natural habitats. Optimizing construction methods and equipment with access and staging areas minimized the disruption to environmentally-sensitive areas. During the construction phase, invasive plant species were removed and replaced with native plantings.
The project’s completion finally provided flood relief to area homeowners, and stormwater management techniques have been implemented to reduce the amount of sediment re-entering the stream channel in years to come.
