Water Stewardship Information Sources
| Citation | Northwest Hydraulic Consultants Ltd. 2011. Upper Lillooet Hydro Project: Overview-level geomorphological assessment. Prepared for Creek Power. |
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| Organization | Creek Power |
| URL | http://a100.gov.bc.ca/appsdata/epic/documents/p357/d34432/1338238804742_bbca42636c15f9f1b9dfde1956756cb9288d2049b36d6a2bd463333fd60259a4.pdf |
| Abstract/Description or Keywords | Northwest Hydraulic Consultants (NHC) is pleased to provide an overview-level fluvial geomorphology investigation of the Lillooet River, Boulder Creek and North Creek watersheds as they relate to the proposed Creek Power hydroelectric project. The purpose of this report is to provide an overview assessment of the fluvial geomorphology of the watersheds and background information for an Environmental Assessment Certificate Application and Project design. Our assessment of the geomorphological conditions in project watersheds concludes: 1) All three watersheds produce very high rates of sediment transport. It is estimated that the intake head pond of each of the three projects will fill and pass the full range of grain sizes at the pre-project rate within one year during average conditions. 2) The mean annual rate of bedload transport at the intakes is estimated to be: a) North Creek 1.0 x 104 m3 /y b) Boulder Creek 2.5 x 104 m3 /y c) Lillooet River 1.0 x 105 m3 /y. 3) The actual annual sediment yields are expected to vary from these numbers by an order of magnitude or more for any given year due to the inter-annual variability in factors which influence the supply and transport of sediment through these systems. These factors include the occurrence of debris flows, landslides, lahars, rockslides and large flood events. 4) The project is not expected to cause any significant changes to the channel morphology or sediment transport regimes within the diversion reaches of any of the three watersheds. In addition, no project related channel morphology changes are anticipated downstream of the diversion reaches. 5) Woody debris is expected to be transported to the three intake sites at least once a year during moderate to high flow events. A portion of this woody debris is expected to accumulate at the intakes, and will require removal. Some of the wood will pass over the proposed intake structures during high flows. |
| Information Type | report |
| Regional Watershed | Howe Sound & Sunshine Coast |
| Sub-watershed if known | Lillooet River, Boulder Creek, North Creek |
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| Project status | complete |
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