Assessment of Juvenile Salmonid Passage at the Young’s Dam Fish Ladder, Scott River, Siskiyou County, CA
Author | Publisher | Year | Pages | Resource Type |
---|---|---|---|---|
Chris Adams | SRCD | 28/01/2025 | 33 | PDF |
We monitored juvenile fish movement in the Young’s Point fish ladder in the summer of 2022 and 2023
using a series of underwater cameras and PIT tag antennas. Camera footage review during the low flow
period in 2022 (less than 30 cfs in channel downstream of ladder) suggests that very few juvenile
salmonids were passing through the ladder, despite large numbers consistently being observed at the
downstream end of the ladder. In 2023 juvenile salmonids were PIT tagged in reaches up and downstream
of the ladder. Six percent of those tagged (9 of 149) were detected at antennas in the ladder and no
detections occurred in the ladder when flow was less than 1.5 cfs. Successful upstream movements of age
0 coho through the ladder were confirmed by PIT detections when flow in the ladder was between 1.5 and
2.5 cfs. We also measured water velocity and hydraulic drop in the ladder at a range of discharges.
Velocities and hydraulic drop were higher than recommended for juvenile fish passage by the National
Marine Fisheries Service (1 foot per second velocity and 6-inch hydraulic drop) at all measured flows,
which includes the minimum flow allowable through the ladder on the date measured (1.85 cfs).
2025, Youngs Dam, Scott River, Scott Valley, SVID, Irrigation, SRCD Projects, Streamflow, Temperature, Water, Water Supply, Video, Summer Surveys