Forest Investment Account (FIA) - Land Base Investment Program
FIA Project 6919002

    Assessment of Water Quality Impacts of the Powell River Community Forest Operations within the Powell River area
Project lead: Powell River Community Forest
Author: Carson, Brian
Subject: Forest Investment Account (FIA) - Land Base Investment Program
Series: Forest Investment Account (FIA) - Land Base Investment Program
Maintenance of water quality is key to the management of the Powell River Community Forest. Two major domestic intakes (Powell River District intake on Haslam Lake and Brew Bay Intake at the mouth of Lang Creek) and numerous individual water licenses lie downstream of the Community Forest Lands. Lang Creek supports the most important fishery resource in the Powell River Area. In order to evaluate whether water quality is being maintained, a rigorous field assessment of fine sediment generation was conducted within the Powell River Community Forest lands. The watershed was subdivided into 6 zones, based on potential risks. The Water Quality Evaluation Protocol, recently developed by the Forest and Range Evaluation Program was chosen as the framework on which the evaluation was conducted. This assessment was based primarily on the forest road network within the watershed and, in particular, sites along the road network where there was a possibility that artificial road drainage might connect to the natural drainage. 80 sites were identified as potentially capable of influencing water quality within the areas managed by the Community Forest. For each of these sites, the protocol provided a means of estimating the magnitude of disturbance, its characteristics and the connectivity between the disturbance and the natural drainage. This data provided an order of magnitude estimate of fine sediment being generated at the site. Each site was then assigned to one of 5 water quality impact classes: “Very Low”, “Low”, “Moderate”, “High” and “Very High”. Of the 80 sites sampled in the whole watershed, 91% fell into the “Very Low” and “Low” Fine Sediment Generating Potential Classes. The remaining 9% fell into the “Moderate” Fine Sediment Generating Class. These results compare favourably with the 1200 province- wide sites evaluated over 2007 and 2008 where 69 % of the sites were rated “Very Low” or “Low”, 25% “Moderate” and 5.5% “High” or “Very High”. The 91% of sites within the watershed falling into the “Very Low” and “Low” classes reflects management that has successfully maintained water quality. For the 7 sites (9%) in the Community Forest found with a moderate rating, none had the potential to directly impact the most sensitive zones. 3 of these seven sites were associated with inter-drainage culverts without resident fish, 3 were associated with Blackwater Creek and one with Washout Creek, both buffered by Mud Lake. Both of these streams support natural resident trout populations and hatchery reared salmon but also suffer from periodic natural turbidity events. The reasons for the “Moderate” ratings for Fine Sediment generation at these 7 sites included: long ditch lines (3 sites) diverted water from old skid trail (2 sites), inherited road location too close to stream (1 site), and broken down cross ditches (1 site). Although not high priority, the feasibility of conducting improvements at these sites should be considered.


Final Community Forest WQ Assessment (1.8Mb)

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Updated August 16, 2010 

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