CONCORD, Mass. – At the request of the city of Middletown, the U.S. Army Corps of Engineers, New England District is proposing to perform emergency streambank protection to stabilize approximately 1,300 feet of the riverbank along the banks of the Connecticut River in Middletown, Conn. The project is located along the banks of the Connecticut River along the eastern side of the John S. Roth Memorial Well Field, on River Road in Middletown.
“The purpose of the proposed project is to restore the 50 foot set-back in the most eroded areas of the well field, protecting the banks from erosion,” said Project Manager Robert Russo, of the Corps’ New England District, Engineering/Planning Division. “Riverbank erosion has jeopardized the integrity of the public water supply for Middletown.”
The well field currently provides approximately 70 percent of the drinking water for the city of Middletown, a city of approximately 48,000 residents. The banks along the river in this area range between 10 and 12 feet high and are composed of fine alluvial material and vegetated with well-established large trees and understory.
Since approximately 1980, greater than 10 feet of bank in the vicinity of Well number 3 has been lost allowing the river to encroach upon the well’s 50-foot required set-back from high water. Without permanent streambank protection, continued action of river currents will further erode the streambank beyond the required 50 foot set-back rendering the most affected wells unusable. This would require the city to provide an alternate source of water for approximately 34,000 residents.
The proposed project will be designed to restore the 50 foot set-back in the most eroded areas of the well field and protect the banks from further erosion, thereby preserving the integrity and function of the well field. The proposed project is to provide streambank protection for this area and is being conducted under Section 14 of the Flood Control Act of 1946. Section 14 provides for the Corps of Engineers to participate in the planning and construction of economically justified streambank erosion control projects in situations where public facilities are threatened.
Due to the emergency nature of this erosion problem, there is a streamlined implementation process allowing the project study and design to be concurrently completed. The intent is to abbreviate the time required for the completion of the project. Section 14 requires a complete and comprehensive solution that solves the immediate erosion problem in a manner that does not obligate or imply future federal participation. Once Section 14 projects are completed, they are relinquished to the local non-federal sponsor for operations and maintenance. The goal of the process is the protection of public infrastructure from present and future erosion with minimal ecological consequences. The city of Middletown is the non-federal sponsor.
The proposed plan is a multi-tiered system consisting of stone revetment along the toe of the bank below the water surface, and then a layer of articulating concrete blocks (ACB) placed along the upper slope leading to the well field. In some areas a level shelf of rooted vegetation along the lower level of the floodplain above the bank may be left intact, which would provide habitat between the ACB and the lower protected bank.
This type of system is necessary given the existing topography of the land adjacent to the river which consists of historic riverbanks at the edge of the channel, forested flood plain several feet above that channel, and then banks formed by artificial fill on which the well field is built, rising approximately 10 feet above the historic vegetated flood plain. The articulating blocks will be placed only along the selected locations of the bank, leaving approximately 33 percent of the existing floodplain forest intact. Stone protection will be placed along the entire toe of the bank, including those sections that will not be reinforced by the articulating blocks.
The upper portion of the bank above the articulating block will be covered with biodegradable erosion fabric and vegetated with woody shrub and vines. Stone revetment will be placed along the toe of the bank including those areas that will not be stabilized with articulating blocks. The construction sequence will involve complete tree and vegetation removal along 1,000 feet of the area where the ACB will be placed, and flank stone protection and select tree removal along 400 feet of toe stone protection.
An Environmental Assessment is being prepared and will be available on request. Coordination with the National Marine Fisheries Service has indicated that the federally endangered shortnose sturgeon inhabits the Connecticut River in the vicinity of the proposed project. It is expected that the proposed project will not have any adverse effects on this species.
The proposed work is being coordinated with the following Federal, state and local agencies: U.S. Environmental Protection Agency; U.S. Fish and Wildlife Service; the National Marine Fisheries Service; the Connecticut Department of Environmental Protection (Inland Fisheries Division); the Connecticut Department of Environmental Protection (Bureau of Natural Resources); the Connecticut State Historic Preservation Office; the city of Middletown; the Middletown Conservation Commission; and the Middletown Water and Sewer Department.
The public notice for this proposed work, with more detailed information and other project alternatives that were considered, is available for review on the Corps website at http://www.nae.usace.army.mil. Select “projects” and then “Connecticut” and then “Emergency Streambank Protection Project, Connecticut River, Middletown, Conn.” Public comments on this proposed work should be forwarded no later than Oct. 24, 2011 to the U.S. Army Corps of Engineers, New England District, Engineering/Planning Division (ATTN: Mr. Robert Russo), 696 Virginia Road, Concord, MA 01742-2751 or by email to robert.s.russo@usace.army.mil.