Location
UMass Amherst
Start Date
28-6-2011 3:45 PM
End Date
28-6-2011 4:05 PM
Description
The Pawtuxet River is the third-largest tributary of Narragansett Bay, with a watershed area of approximately 230 square miles. As with most urban rivers, the Pawtuxet and its tributaries have been extensively modified for industry, transportation, and development. Today, there are more than 140 dams on the Pawtuxet system, most of which are less than 20 ft. in height. Small dams degrade riverine habitat, water quality, and biodiversity; on the Pawtuxet, they have caused extirpation of native anadromous fish runs. Large areas of the Pawtuxet’s natural floodplains have beenfilled or modified, creating flooding problems for communities along the river corridor. The Narragansett Bay Estuary Program, the USDA Natural Resources Conservation Service, R.I. Dept. of Environmental Management, EA Engineering, Science and Technology, and other partners are restoring ecological functions to the lower Pawtuxet River and Narragansett Bay watersheds by removing a large portion of the Pawtuxet Falls Dam, the first downstream dam on the system (located at the head of tide), and creating a low-flow fish passage channel by using the natural pool and bedrock formations. The project will restore migratory fish habitats, reestablish ecological connections between the lower Pawtuxet River and Narragansett Bay, and enhance natural riverine functions and values. River restoration in such an urbanized setting presents many social and technical challenges. The dam is a prized historic and aesthetic feature of one of the most historic communities in Rhode Island. Its impoundment or backwater effect impacts approximately 5 linear river miles; HEC-RAS modeling is being used to design the restoration and predict post-removal changes in water surface elevation and flow. The Pawtuxet’s industrial legacy also presents challenges, requiring evaluation of potential risks to human health, with mitigation measures incorporated as necessary into restoration plans. We will discuss the social, ecological, and technical aspects of the projects to inform other urban river restorations.
Session B6- Dam Removal on Main Street in Historic Pawtuxet Village
UMass Amherst
The Pawtuxet River is the third-largest tributary of Narragansett Bay, with a watershed area of approximately 230 square miles. As with most urban rivers, the Pawtuxet and its tributaries have been extensively modified for industry, transportation, and development. Today, there are more than 140 dams on the Pawtuxet system, most of which are less than 20 ft. in height. Small dams degrade riverine habitat, water quality, and biodiversity; on the Pawtuxet, they have caused extirpation of native anadromous fish runs. Large areas of the Pawtuxet’s natural floodplains have beenfilled or modified, creating flooding problems for communities along the river corridor. The Narragansett Bay Estuary Program, the USDA Natural Resources Conservation Service, R.I. Dept. of Environmental Management, EA Engineering, Science and Technology, and other partners are restoring ecological functions to the lower Pawtuxet River and Narragansett Bay watersheds by removing a large portion of the Pawtuxet Falls Dam, the first downstream dam on the system (located at the head of tide), and creating a low-flow fish passage channel by using the natural pool and bedrock formations. The project will restore migratory fish habitats, reestablish ecological connections between the lower Pawtuxet River and Narragansett Bay, and enhance natural riverine functions and values. River restoration in such an urbanized setting presents many social and technical challenges. The dam is a prized historic and aesthetic feature of one of the most historic communities in Rhode Island. Its impoundment or backwater effect impacts approximately 5 linear river miles; HEC-RAS modeling is being used to design the restoration and predict post-removal changes in water surface elevation and flow. The Pawtuxet’s industrial legacy also presents challenges, requiring evaluation of potential risks to human health, with mitigation measures incorporated as necessary into restoration plans. We will discuss the social, ecological, and technical aspects of the projects to inform other urban river restorations.
Comments
Thomas Ardito is restoration program manager for the Narragansett Bay Estuary Program in Narragansett, Rhode Island, and founding director of Center for Ecosystem Restoration in Saunderstown, Rhode Island. Previously, he worked for the NOAA Restoration Center in Silver Spring, Maryland. Mr. Ardito has worked on restoration of rivers, wetlands, salt ponds, and other coastal and aquatic habitats. His current work focuses on urban habitat restoration with emphasis on urban rivers, parks and ponds, and dam removal in Rhode Island and Massachusetts. He co-chairs the River Restoration Working Group of the interdisciplinary Rhode Island Habitat Restoration Team.