CONCORD, Mass. – The city of Bristol and the Natural Resources Conservation Service (NRCS) are seeking a permit from the U.S. Army Corps of Engineers, New England District to conduct work in waters of the United States in conjunction with stabilizing a failing stream bank upstream of the Jacobs Street Bridge in Bristol, Conn.
Storm flows associated with Tropical Storm Irene resulted in a bank failure along the left bank of the Pequabuck River upstream of Jacobs Street in Bristol. The bank failure occurred approximately halfway between the Jacobs Street and Tulip Street bridges. Given the proximity of the failure to existing residences and the severity of the failure, the Natural Resources Conservation Service has offered to partially fund stabilization efforts, with the caveat that this money be expended as soon as possible.
Improvements must be made to this area due to the severity of impacts as well as the potential for long-term damage to structures if erosion continues unabated.
The Pequabuck River through Rockwell Park is a relatively natural channel with riffle/pool morphology. The channel is laterally unconfined and is located in a broad valley of stratified drift outwash sediments. The substrate of the river through the park consists of coarse sand, gravel, stones, and boulders while the banks are steep and vegetated, underlain with sandy till soil.
The applicants propose natural stabilization of the bank through regrading and re-vegetation. Conceptual plans for this alternative call for relocating the toe of the slope some 28 feet into the existing channel. This fill in the channel would be offset by the excavation of material from the right bank. The channel width would be retained at 30 feet with a bankfull width of 42 feet and bankfull depth of three feet. The realignment would entail the relocation of approximately 340 linear feet of channel upstream of the Jacobs Street Bridge, but would not affect the existing park facilities on the right bank.
Results of hydraulic modeling suggest that this project will not have any significant adverse impacts to the water surface elevation of the Pequabuck River. Encroachment (floodway) modeling is ongoing to verify that the project meets the FEMA standard of less than 0.01 feet of rise.
The application for the federal permit was filed with the Corps of Engineers in compliance with Section 404 of the Clean Water Act, which regulates the discharge or fill of material in United States waters, including
wetlands. The public notice can be viewed on the Corps website at http://www.nae.usace.army.mil. Select Regulatory/Permitting and then weekly public notice.
Public comments on the Corps permit review (File # NAE-2011-2156) should be forwarded no later than Nov. 23, 2011 to the U.S. Army Corps of Engineers, New England District, Regulatory Division (ATTN: Michael Riccio), 696 Virginia Road, Concord, MA 01742-2751. Additional information is available from Permit Project Manager Michael Riccio at 978-318-8685 or toll free 800-343-4789 or 800-362-4367 (if calling from within Massachusetts) or by email to: michael.s.riccio@usace.army.mil.