Essex 19 Fish Passage

Project Name: Essex 19 Fishway Project

Summary: Innovative design provides downstream passage

Client: Green Mountain Power Company

Project Location: Essex, VT

Project Size: 10 MW

Services Provided:
•  Fish Passage Conceptual Design
•  Fish Passage Engineering –
    Downstream Design
•  Bid Specifications and Drawings
•  Construction Services
•  Fish Passage Effectiveness Study

Project Timeframe:
1994 - 1996

Relationship with Client: Since 1980

Client Needs:
As part of complying with FERC license conditions, Green Mountain Power (GMP) needed to install a downstream fish passage for adult and juvenile salmonids at their Essex 19 hydroelectric facility.
Kleinschmidt Solution:
Kleinschmidt was engaged to design and provide construction services for the installation of the fish passage facility. To address challenging intake configuration issues, Kleinschmidt’s design included two steel entrance boxes that had to be installed into a very narrow space behind existing trashracks necessitating close control of the entrance box water level to prevent fish from impacting the downstream face of the entrance boxes. To address a 50 cfs minimum flow requirement, Kleinschmidt conducted an investigation showing that while it wasn’t presently economically beneficial to recycle fishway attraction flow, the design incorporated cost effective provisions for the potential future installation of a high volume pump to utilize attraction flow in excess of the fish transport flows for generation. Other features of the design included incorporating a discharge chute lining that minimized fish injury as well as a chute discharge configuration that decreases the impact and travel of the fish into the plunge pool. Kleinschmidt performed radio telemetry fish effectiveness studies in the two summers following construction.
Client Benefits:
The design, approval, and construction of the fishway was placed on an accelerated schedule to take advantage of available corporate funding, meet agency requested operational deadlines, and to perform the work with the least cost during the summer period of low river flows.