Lower Churchill River Weir
In 1994, Manitoba Hydro and the Town of Churchill initiated the Lower Churchill River Water Level Enhancement Weir Project. The project was a collaborative effort to investigate mitigation options intended to partially address lower water levels occurring along the lower Churchill River as a result of Manitoba Hydro's Churchill River Diversion (CRD). The design included the construction of a rockfill weir across the Churchill River, and other ancillary components. The primary objective of the project was to enhance water levels along a 10-km reach of the lower Churchill River, thereby improving boating and increasing the amount and productivity of fish habitat to support fish populations in that reach of the river.
NSC's role in the project:
- Planned and conducted all aquatic environment and resource use studies required to describe the existing environment.
- Provided input to support selection and design of a preferred project configuration.
- Wrote the aquatic environment and resource use components of the Environmental Impact Statement (EIS), as well as the Aquatic Effects Monitoring Plan for construction and operation, and the No Net Loss Plan.
- Conducted construction monitoring to document potential changes to water quality and marine mammals use of the lower Churchill River and upper Churchill River estuary (seals, beluga).
- Conducted operation monitoring to:
- Assess potential changes to water quality, lower trophic levels, fish communities, and fish movements in the lower Churchill River and Goose Creek.
- Assess potential changes to use of the lower Churchill River and upper Churchill River estuary by seals and beluga.
- Document anticipated increase and change to aquatic habitat in the lower Churchill River, the success of ancillary habitat enhancement measures, and fish passage at two boulder-garden style fishways.
- Monitored recreational fishing during the operation phase of the project.
- Prepared an Evaluation of Weir Performance for Manitoba Hydro and the Town of Churchill. This document assessed the accuracy of all predictions made in the EIS using data collected as part of post-project monitoring.