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Lower Assunpink Creek Ecosystem Restoration

Project Background

The U.S. Army Corps of Engineers Philadelphia District initiated an environmental restoration project for the lower Assunpink Creek area under authority of Section 1135 of the Water Resources Development Act, as amended. Section 1135 provides authority for determining if the operation of an existing Federal project has contributed to the degradation of the quality of the environment and for modifying the structure or operation of a Federal project to improve the quality of the environment in the public interest. The City of Trenton, New Jersey, is serving as the non-Federal project sponsor for the Assunpink Creek project.

The Assunpink Creek is 25 miles long, and drains approximately 91 square miles in central New Jersey. The main tributaries that feed Assunpink Creek are Shabakunk Creek and Miry Run. The headwaters begin in Millstone Township, in Monmouth County, and flow into the Delaware River in Trenton.  The Lower Assunpink Creek Ecosystem Restoration Project study area is located on a 3- mile section of the Assunpink Creek between the Delaware River and the Trenton city limits. Several former industrial sites, abandoned bridges, and a 500-foot section of the creek between Broad and Warren Streets, contained within a buried box culvert were identified as candidates for ecological restoration. The buried box culvert, known locally as the Broad Street culvert, was evaluated during the feasibility study and approved for removal and restoration of a natural creek channel. During the same period, the Broad Street culvert experienced several structural failures, which increased the urgency to implement a restoration action that would also address a public safety hazard.

The Broad Street culvert removal project is located in the heart of the downtown Trenton business and historic district on a recovering urban stream that also serves to connect several greenway and urban park facilities. The project site is also the location of the Second Battle of Trenton during the American Revolution.  The day lighting of the stream will occur by removal of the culvert structure, allowing the stream to be exposed to natural sunlight. The resulting open channel design will improve anadromous fish migration, as low-light conditions can disorient migrating fish, hindering their ability to spawn upstream. The project will also benefit businesses adjacent to the site, provide recreational options for visitors and local residents, and provide historical and educational opportunities for the community.

Current Status

The Army Corps of Engineers, Philadelphia District executed a Project Partnership Agreement with the City of Trenton in September of 2009. Current project plans are under review by permitting and resource agencies. The City of Trenton, the non-Federal sponsor, developed a design alternative to address the energy utilities that cross the creek. The Corps is in the process of responding to New Jersey Flood Hazard Area and Freshwater Wetlands General Permit application review comments. Soil erosion and sediment control plans have been submitted and comments received from Mercer County Soil Conservation District.  Advertisement of the construction contract is scheduled for the end of the 4th quarter of fiscal year 2014 pending the receipt of State real estate easements and permits.

Project Goals

The goal of the Lower Assunpink Creek Ecosystem Restoration Project is to restore migratory fish habitat, improve the overall stream ecology of Assunpink Creek and enhance urban recreational opportunities. Project goals will be accomplished through day lighting the creek by removing the Broad Street culvert and creating of an open-channel system. Additionally, restoring the freshwater ecology and creating recreational and cultural opportunities for the public will benefit the overall economy of the City of Trenton and the region.