CONCORD, Mass. – The U.S. Army Corps of Engineers, New England District is conducting the Pawcatuck River Coastal Storm Risk Management (CSRM) feasibility study and is proposing a plan to reduce potential storm and flooding impacts to Westerly, Charlestown, South Kingstown and Narragansett, Rhode Island.
The study area includes about 28 miles of moderately developed coast in the towns of Westerly, Charlestown, South Kingstown and Narragansett in Washington County. The floodplain completely encompasses the coastal barrier beaches and salt ponds in the area. There is a demonstrated need for coastal resiliency measures to be implemented in south coastal Rhode Island. Residential and commercial properties in the Pawcatuck River coastal floodplain are all vulnerable to inundation from coastal storms. The study area includes about 4,000 structures most of which are residential. The total value of the existing residential and commercial inventory is estimated to be worth more than $600 million.
This study is being conducted under existing authorities and under the Disaster Relief Appropriations Act of 2013 for Hurricane Sandy impacts, according to Project Manager Christopher Hatfield, of the Corps of Engineers, New England District, Planning Division in Concord, Mass.
The Tentatively Selected Plan for the Pawcatuck River CSRM project consists of elevating the first floors of 341 structures in the four study area communities. The first floors will be elevated to a height corresponding to the Federal Emergency Management Agency (FEMA) designated Base Flood Elevation (BFE), ranging from +11 feet North Atlantic Vertical Datum of 1988 (NAVD88) to +17 feet NAVD88, plus 1 additional foot in accordance with state building code and another 0.37 feet to account for historic sea level rise over the next 50 years. Properties eligible for elevation are: 45 structures in Westerly; 44 structures in Charlestown; 172 structures in South Kingstown; and 80 structures in Narragansett.
Forty-six other mainly commercial structures in the study area, though found to be highly susceptible to coastal flooding damage, do not lend themselves to elevation (concrete, brick or metal structures). Instead, they may be able to apply other flood-proofing measures in these situations.
Elevation of individual structures will rely on conventional residential construction methods. Structures will be elevated using lifting jacks and supported on temporary cribbing. The existing foundation for the participating home will be demolished and temporary utility connections put into place to allow occupants to remain in the structure throughout construction. Those structures in the AE-zone of the floodplain will be provided with a new concrete wall foundation. Those in the VE-zone will be placed on new concrete piers. Once ready, structures will be lowered onto new foundations and the permanent utility connections made.
The Pawcatuck River CSRM feasibility study considered a range of structural and nonstructural measures to reduce the risk of storm damage. Through an iterative planning process, potential coastal storm risk management measures were identified, evaluated and compared. Initial screening of alternatives determined that detailed study of structural (sheet pile floodwalls and tide gates), soft structural (beach fill/nourishment), and nonstructural (elevation and buyout of properties) alternatives should be conducted in Westerly due to the density of development there. Conversely, only non-structural alternatives made sense for full evaluation in the towns of Charlestown, South Kingstown and Narragansett.
The non-Federal project partner for the study is the Rhode Island Coastal Resources Management Council. The non-Federal sponsor for project implementation has not been identified at this point in the study, but a non-Federal sponsor will be required before a project could be implemented.
Approximately 221 of the structures proposed for elevation date from 1900 to 1966; most date to the 1950s. There are no 19th century buildings in the inventory. Most are small, single-story houses on small lots scattered throughout the study area; however, there are some that comprise cohesive neighborhoods. None of the buildings merit individual distinction for eligibility for the National Register of Historic Places. One neighborhood potentially could be eligible for the National Register under Criterion A for its association with the early to mid-20th Century development of coastal communities in Rhode Island: 17 houses on Champlin Avenue in Narragansett. Elevating buildings in this neighborhood could have an effect on historic properties. This determination is being coordinated with the Rhode Island State Historic Preservation Office and the Narragansett Tribal Historic Preservation Office.
An Integrated Report (combined Detailed Project Report and Environmental Assessment) was prepared for the Pawcatuck River CSRM project. A preliminary determination was made that an Environmental Impact Statement is not required under the provisions of the National Environmental Policy Act of 1969.
The proposed plan is being coordinated with: U.S. Fish and Wildlife Service; U.S. Environmental Protection Agency; U.S. National Marine Fisheries Service; Rhode Island Department of Environmental Management, Office of Water Resources, Bureau of Natural Resources, Division of Fish and Wildlife - Marine Fisheries; Rhode Island Coastal Resources Management Council; The Nature Conservancy, Rhode Island Chapter; Save the Bay; Wood-Pawcatuck Watershed Association; Rhode Island Historical Preservation and Heritage Commission; Narragansett Indian Tribe – Tribal Historic Preservation Office; and the towns of Westerly, Charlestown, South Kingstown and Narragansett.
A copy of the report is available via the website http://www.nae.usace.army.mil/Missions/Projects-Topics/ or from Project Manager Christopher Hatfield at 978-318-8520. Any person who has an interest that may be affected by the proposed project may request a public hearing. The request must be submitted in writing within 30 days and must clearly set forth the interest and the manner in which the interest may be affected.
Public comments on this proposed plan should be forwarded no later than Nov. 21, 2016 to the U.S. Army Corps of Engineers, New England District, ATTN: Planning Division (Mr. Christopher Hatfield), 696 Virginia Road, Concord, MA 01742-2751 or by email to cenae-ep@usace.army.mil.