Predicted Changes in Peace River Channel Morphology and Sediment Transport Related to the Site C Clean Energy Project

Predicted Changes in Peace River Channel Morphology and Sediment Transport Related to the Site C Clean Energy Project

Author: C. Nistor, V. Martin
Conference: Canadian Hydrotechnical Conference 2015
Date: April 29-May 2, 2015

The Site C Clean Energy Project is a third dam and 1100 MW hydroelectric generating station on the Peace River in northeastern British Columbia, Canada. BC Hydro plans to start construction in the summer of 2015. This paper presents the predicted changes in channel morphology and suspended sediment dynamics during Project operations that were described in the Environmental Impact Statement (EIS) for the Project.

The reservoir is predicted to trap 70% of the incoming sediment delivered from tributaries and from shoreline erosion induced around the reservoir perimeter. However, sediment deposition on the reservoir bed is predicted to reduce the initial reservoir volume by only 2.5% after 50 years. The mean annual suspended sediment load of the Peace River immediately downstream from the dam is predicted to be reduced by 54% compared to baseline conditions. Farther downstream at the Town of Peace River, Alberta, the predicted reduction in sediment load is only 2%, due to the large sediment inputs delivered to the Peace River by intervening tributaries. The Peace River has a cobble-gravel bed extending for several hundred kilometres downstream from the Site C dam site, and the sediment that will be trapped in the reservoir is much finer than the bed material in this section of the river.

Long-term field observations indicate that the bed material in this part of the river is generally immobile due to flow regulation at the two existing dams, which has led to ongoing bed material aggradation at tributary confluences and vegetation encroachment on gravel bars. The Project will not change the flow regime of the river with respect to bedload transport competence, and so is not expected to cause any incremental change in channel morphology downstream from the Site C Dam under normal operating conditions.

 

Download the full technical paper.

Download

Recent Insights

November 2021
Knight Piésold's Projects Commended at Prestigious Awards
November 2021
Engineer of Record Services for Tailings Facilities
November 2021
Gearing Up for Growth in Zambia
October 2021
Knight Piésold, aliado de la minería sustentable
September 2021
Knight Piésold Chile enfoque personalizado e integral de trabajo al estilo boutique
September 2021
Company Uses Innovative Ideas in Municipal Project
August 2021
South Africa Must Focus on STEM Skills to Enable Development
July 2021
Business Success Stories: Knight Piésold
July 2021
Holistic Approach to Mine and Industrial Water Management
July 2021
Selection of Undrained Shear Strength Parameters of Residual Soils and their Application in Stability Analysis
June 2021
Knight Piésold Focused on Africa's Infrastructure Development
June 2021
Century-old Knight Piésold Remains Committed to Clients and Communities in Phalaborwa
May 2021
Very Few Consulting Firms Reach 100 Years – Knight Piésold Celebrates with Optimism
April 2021
Knight Piésold Celebrates 100 Years of Excellence in Africa
April 2021
Video: Knight Piésold Celebrates 100 Years of Engineering Excellence
April 2021
Opportunities Abound to Support Africa's Resilient Growth - Knight Pièsold
April 2021
Firm Expands Service Offering
March 2021
Celebrating 100 Years of Engineering Excellence
February 2021
Improved Tailings Disposal Could Reduce Water Use
January 2021
Your Community, Your Neighbour