Maintenance dredging of the Federal navigation channel near the Chelsea Street Bridge in East Boston and Chelsea is being proposed by the U.S. Army Corps of Engineers, New England District, with work anticipated by 2012. A new vertical lift bridge will replace the existing Chelsea Street Bridge, enabling the Corps to modify the Federal navigation channel in that area. Although the Chelsea Creek navigation channel was authorized to a width of 225 feet under the River and Harbor Act of 1962, the existing Chelsea Street Bridge prevented the channel from ever reaching its authorized width. “The project area is located approximately 125 feet downstream of the bridge to approximately 350 feet upstream of the bridge,” stated Mike Keegan, Project Manager with the Corps’ New England District, Programs/Project Management Division. “There are two alternatives currently under consideration to widen the channel. Both alternatives are located in disturbed areas where previous vehicular or railroad bridges, and utilities were constructed.” Under the first option, a minimum 140-foot-wide channel would be established near the new bridge. A second option calls for a minimum 175-foot-wide channel. The 175-foot alternative depends on bulkhead modifications that non-Federal interests must design and complete before widening can occur to that width. Both options would deepen the channel to -38 feet Mean Lower Low Water (MLLW), as authorized by the Water Resources Development Act of 1990. Currently, fuel tankers moving through Chelsea Creek have less than six feet of clearance at the existing Chelsea Street fenders. The new vertical lift bridge under construction will remove any navigation channel obstruction. Following completion of the new bridge, the Federal project aims to quickly widen the navigation channel in the Chelsea Street Bridge area. This widening could enable larger vessels to safely access oil terminals upstream, potentially increasing home heating oil volume and reducing transportation costs for various Massachusetts commodities while addressing hazardous navigation conditions. Channel widening work is expected to commence early in 2012, shortly after the new bridge opens. Approximately 34,700 cubic yards of material, including two feet of over depth dredging, would be removed mechanically to widen the channel to 140 feet. Of this total, roughly 5,100 cubic yards of surface material unsuitable for ocean placement will go into the existing Confined Aquatic Disposal (CAD) container built during the Boston Harbor Navigation Improvement Project deepening, located at the upper end of the Chelsea Creek navigation channel. The remaining 29,600 cubic yards will be deposited at the U.S. Environmental Protection Agency-designated Massachusetts Bay Disposal Site (MBDS), situated 20 miles offshore. This active site has been used for chemically and biologically tested dredged material. An Environmental Assessment is currently in preparation. Whale observers will be stationed on scows traveling to the MBDS from Feb. 1 to May 31 to protect endangered right whales from potential ship strikes. The Corps is evaluating impacts on Essential Fish Habitat and has preliminarily determined that designated fisheries resources will not be significantly affected. Local traffic is not expected to be impacted.
Army Corps of Engineers will Dredge Chelsea Creek by 2012
