Water Stewardship Information Sources

Citation Gaboury, M and McCulloch, M. 2002. Fish habitat restoration designs for east Vancouver Island watersheds. Prepared for BC Conservation Foundation.
Organization BC Conservation Foundation
URL http://www.bccf.com/steelhead/pdf/finalsept02.pdf
Abstract/Description or Keywords Under the auspices of the BC Ministry of Water, Land and Air Protection, BC
Conservation Foundation and LGL Limited identified potential restoration sites in five
watersheds on east Vancouver Island including Chemainus, Nanaimo, Little Qualicum, Oyster,
and Quinsam rivers. The report provides instream restoration designs in the mainstems of the
five major watersheds, as well as Deadwood Creek, Haslam Creek, Little Oyster River, and Cold
Creek. The restoration designs target all life stages of salmonids found within the proposed
restoration sections of the five watersheds, but in particular the holding and rearing habitats for
those species that spend an extended period of time as juveniles in fresh water. A total of about
41 km of stream and 371 structures were prescribed for instream restoration, with more than 4
km of off-channel habitat being identified for further surveys and design. Boulder-ballasted
LWD structures, riffle enhancement, and spawning gravel placement were restoration treatments
recommended. The estimated cost to implement restoration work at all 371 restoration sites was
approximately $1,007,800.
Flow release options for Fourth Lake were examined to determine if water temperatures
could be increased to benefit trout rearing in the Nanaimo River downstream of the lake outlet
pipe. From the analysis, it was estimated that flow releases of 2 m3
/s from a fixed elevation
invert at 8 m below Full Supply Level will provide, on average, temperatures of 14 to 16 °C in
the Nanaimo River below Fourth Lake from 1 July to 30 September. Increasing summer
temperatures from the existing range of 6.5-14 °C to an estimated range of 14-16 °C would affect
at least 9 km of river or 180,000 m2
of habitat. Increasing the outlet discharges to between 2.5
and 3.2 m3
/s would require a lower elevation invert and would probably result in lower
temperatures in the Nanaimo River. However, lower temperatures could be mitigated by the
construction of an outlet structure that allows for water releases over a range of lake elevations
rather than from a fixed elevation. The former structure would be more effective for steelhead /
rainbow trout production. Temperature and volume values should be refined after a water
balance for the reservoir has been completed.
Information Type report
Regional Watershed Vancouver Island South, Vancouver Island North
Sub-watershed if known deadwood creek, haslam creek, little oyster river, cold creek
Aquifer #
Project status complete
Contact Name
Contact Email