The fish-friendly design of the Wells Hydroelectric Project facilitated the achievement of the project survival standards specified by the Wells Habitat Conservation Plan (HCP). The relevant standards for juveniles are 93% Measured Project Survival, and 95% Calculated Dam Passage Survival. Project survival includes survival through the reservoir, dam, and tailrace.
Calculated Dam Passage Survival (Based on Bypass Guidance Efficiency)
Yearling Sockeye >95%
Subyearling Chinook >95%
Wells Bypass Guidance Efficiency:
Yearling Chinook 92.0%
Yearling Steelhead 92.0%
Yearling Sockeye 95.3%
Subyearling Chinook 96.2%
Measured Juvenile Project Survival:
1998: Methow Yearling Chinook 99.7%
1999: Methow Yearling Steelhead 94.3%
2000: Methow Yearling Steelhead 94.6%
2010: Methow & Okanogan Yearling Chinook 96.4%
2020: Methow & Okanogan Yearling Chinook 95.2%
5-Year Average for Yearling Spring Migrants 96.0%