Project Name: Greenville Dam Fish Passage Project
Summary: Alternative design reduced costs by 30%
Client: Department of Public Utilities
Project Location: Norwich, CT
Project Size: 1.6 MW
• Fish Passage Conceptual Design
• Fish Passage Feasibility Study
• Fish Passage Engineering Design
• Federal, State, and Local
• Specifications and Bid Services
• Construction Services
Project Timeframe: 1998 - 1999
Relationship with Client: Since 1998
The Greenville Dam project is the first dam on the Shetucket River. During relicensing, the USFWS and Connecticut Department of Environmental Protection imposed a requirement for upstream and downstream passage of American shad, Atlantic salmon, and alewife at the project. The agencies recommended that an ice harbor fishway be installed for upstream passage. The cost of the proposed fishway was substantial, in part driven by an agency requirement that it needed to be designed to handle a projected fish run size which the Department of Public Utilities (DPU) felt was unrealistically high.
To reduce costs, Kleinschmidt and Lakeside Engineering assisted DPU in proposing a new approach to upstream fish passage. The new approach incorporates a fish lift, sized to pass the entire run. The lift operates about every four hours until the run size requires more frequent operation. In this way the fish lift can accommodate DPU’s and agency expectations of run sizes. Kleinschmidt developed cost-benefit analyses of various conceptual options, provided final design and specifications preparation, handled all federal, state, and local construction permitting, and construction management. The downstream fish passage consists of an angled rack structure situated in the power canal at the upstream end with automated trashrake, gated entrance chamber, and transport pipe. The rack structure is used to redirect the migrants back to the river downstream from the main dam.
The upstream fish lift cost significantly less (30%) than the agency fishway proposal. The downstream approach allowed a single passage system instead of two (one at each powerhouse), saving initial installation and maintenance costs.