Citation | BC Hydro. 2011. Ash River watershed: Watershed Plan, Final Draft. BC Hydro. |
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Organization | BC Hydro |
URL | http://fwcp.ca/app/uploads/2015/07/ash_watershed_plan.pdf |
Abstract/Description or Keywords | The Ash River watershed is situated about 40 km northwest of Port Alberni in central Vancouver Island, between the Beaufort Range and Strathcona Provincial Park. The upper Ash watershed is dominated by mountains up to 2000 m, which form the boundary between the Ash, Campbell and Puntledge watersheds, and small areas of permanent snowpack exist there. From Oshinow Lake at elevation 410 m, the Ash River drops a further 80 m in 13 km to Elsie Lake Reservoir. The lower parts of the watershed have lower relief than the upper basin. Below Elsie Lake Reservoir the lower Ash River flows into the Stamp River and from there into the Somass River before meeting the ocean at Port Alberni. There are three lakes on the Ash River mainstem, Oshinow, Elsie and Dickson Lakes, and several smaller lakes on tributaries. The Ash River basin is in the transition zone between the wet west coast and drier east coast climates of Vancouver Island. The basin is affected by frontal storms arriving from the southwest off the Pacific Ocean with strong, moist winds that bring heavy precipitation for durations of a few hours to a few days. Monthly rainfall can be as high as 800-900 mm between November and March. Peak inflow, however, occurs from May to July from snow melt, whereas August and September are low flow months. The Ash River watershed is in the traditional territories of the Hupcasath First Nation and Tseshaht First Nation. The Ash River project, completed in 1958 by the B.C. Power Commission, consists of Elsie Dam at the outlet of Elsie Lake Reservoir and four saddle dams. Water is diverted from Elsie Lake Reservoir through a 7.8 km tunnel and penstock to a powerhouse on the shoreline of Great Central Lake (Figure 2). The plant usually operates at maximum capacity (10.7 m 3 /s), except in late summer when inflows are low and during a 1-2 week annual maintenance period, usually scheduled for August. Flows are released down the Ash River from Elsie Dam to support fish and other objectives, according to operations described in the Ash River Project Water Use Plan (BC Hydro 2004). Updated minimum flows agreed to in the WUP are 3.5 m3 /s from May 1 to October 31; 5 m3 /s from November 1 to April 30; and two separate pulse flows for adult steelhead migration, of 10 m3 /s for two days between August 1 and September 30. |
Information Type | report |
Regional Watershed | Vancouver Island North |
Sub-watershed if known | Ash River |
Aquifer # | |
Comments | |
Project status | complete |
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