School of Aquatic and Fishery Sciences

Columbia Basin Performance Measures

Adult Passage Exposure Results

graph

Adult Steelhead Query Parameters
Year	2025
Project	Bonneville
River Parameter	Temperature Tailrace
Critical Temperature Tailrace Value	15 °C
Calculate Exposure	Above Critical Value
River Parameter Data Fill	No
Query Dates	1/1 - 12/31

Total Run Period (Jan 1 - Dec 31)
Total Number of Fish Observed	156869
Percent of Total Run Analyzed [Number Observed]	78.41 % [123008]¹
Temperature Tailrace Exposure Index	21.59 °C
Percent of Fish Exposed [Number Exposed]	99 % [121859]
Number of Days Fish Exposed	101

Middle 80% of Run Period (Jul 12 - Sep 21)
Number of Fish Observed	126562
Percent of Middle 80% of Run Analyzed [Number Observed]	85.64 % [108395]
Temperature Tailrace Exposure Index	21.95 °C
Percent of Fish Exposed [Number Exposed]	100 % [108395]
Number of Days Fish Exposed	55

Middle 50% of Run Period (Jul 24 - Aug 26)
Number of Fish Observed	80860
Percent of Middle 50% of Run Analyzed [Number Observed]	100 % [80860]
Temperature Tailrace Exposure Index	22.01 °C
Percent of Fish Exposed [Number Exposed]	100 % [80860]
Number of Days Fish Exposed	34

Run Dates
First Day of Run	Jan 1
5% of Run passed	Jul 5
10% of Run passed	Jul 12
50% of Run passed	Aug 5
90% of Run passed	Sep 21
95% of Run passed	Sep 30
Last Day of Run	Dec 31

Date(s) When Temperature Tailrace Crosses 15 °C
May 27

1. Total Run Analyzed [123008] is less than total observed during the period [156869]. Only fish observed on days with River Parameter data are analyzed.