Fish Habitat Enhancement

Pomperaug River

The Pomperaug River Watershed is an 89-square-mile resource that includes three primary river systems, a stratified drift aquifer, and good-to-high quality habitat. The Audubon Center at Bent of the River property lies in the lower section of the Pomperaug River’s main stem surrounding just under two miles of river. Despite being a protected bird sanctuary with 660 acres of forest, meadows, and wetlands, a history of agricultural activity, channelization, erosion, and deposition from upstream impairments has decreased the overall instream habitat quality.

The Pomperaug River Watershed Coalition commissioned a report to evaluate the low-flow stresses to physical habitat and fish community, titled Assessment and Restoration of Instream Habitat for the Pomperaug, Nonnewaug and Weekeepeemee Rivers of Connecticut, January 2007. As a result of the study, it was determined that the greatest overall benefit could be achieved through the introduction of large woody debris (LWD) within the river. Princeton Hydro was hired to provide design and permitting guidance to place over ten LWD habitat structures within the river to enhance fish habitat. The features were placed along a 0.72 mile reach of the Pomperaug River.

The design plan was intended to provide the greatest benefit with the least amount of disturbance to the property, its users, and the river itself. Emphasis on LWD and avoiding significant bank reconstruction limited the intensiveness of the activities in regard to managing exposed stream bank soils or dangers of drastically altering floodplains while significantly enhancing instream habitat.

Princeton Hydro specifically limited the scope and complexity of engineering services for this project and worked with the client and regulators to help set a precedent to encourage simpler, proactive LWD enhancement projects throughout the state. With New England’s long history of clearing woody debris from rivers, many rivers lack the variability and complexity created by LWD and could significantly benefit from LWD enhancement projects.