Water Stewardship Information Sources

Citation Greenbank Environmental Inc. 2011. Alouette Project Water Use Plan: Allouette Water Temperature. BC Hydro.
Organization BC Hydro
URL https://www.bchydro.com/content/dam/hydro/medialib/internet/documents/planning_regulatory/wup/lower_mainland/2011q2/alumon-5_yr3_2011-04-01.pdf
Abstract/Description or Keywords Water temperature in the Alouette River, downstream of the Alouette Dam continues to
be a concern for BC Hydro, environmental agencies and stakeholders. In response to
these concerns and other potential low-flow issues, BC Hydro changed the operation of
the Alouette Dam by fully opening the low level outlet (LLO) in 1996 to increase the
minimum flows. It has been agreed by the fisheries technical committee (FTC) that the
increase in flows has improved the temperature conditions, however, uncertainties
regarding the extent potential of high water temperature impacts remain.
To address these uncertainties, BC Hydro has commissioned a water temperature
monitoring program to measure water temperatures throughout the watershed, including
the reservoir, to better assess the possible range of operational changes that can be
taken to mitigate for measured impacts. This Year 3 report summarizes the 2010
temperature data and provides comparisons to earlier years.
Water temperatures in the plunge pool just downstream of the Alouette Dam generally
ranged from a low of about 4°C in December and January and generally increased from
February with peak temperatures observed in late August and early September. Water
temperatures did not reach lethal levels for salmonids. Water temperatures reached a
high of 19°C to 22°C from 2000 through 2010. Weekly mean water temperatures were
highest at the end of August and were near 18°C in the summer of 2010.
Information Type report
Regional Watershed Lower Fraser
Sub-watershed if known Alouette River
Aquifer #
Project status complete
Contact Name
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