Decheeka Falls Salmon Passage Assessment, Tahltan River (Stikine River Watershed)

Decheeka Falls is located in the Tahltan River watershed in a location that both Chinook and sockeye migrate enroute to the upper Tahltan River and to Tahltan Lake, respective salmon species spawning locations. This natural site has been a known site of concern for salmon passage having attention from Alaska State fisheries staff and Canadian fisheries staff in the 1950’s and 1960’s. It is not completely recorded but apparently remedial work was attempted during this time including both salvage transport of salmon and remedial passage efforts. In recent years the site has become more of a concern again with expected sockeye salmon numbers not completely materializing at the Tahltan Lake weir upstream. This may be due to significantly below average Tahltan River flow levels recorded for at least the past four years. Observations of salmon leaping at the Falls and pooling below the area have been recorded from helicopter surveys in 2017 and 2018. It has been suggested for years that passage at the Falls is limited at particular flows with low flow conditions being the suggested limiting condition however this is not for certain due to the absence of surveys during a range of flows. These conditions would impact the most significant stock to migrate the Falls, Tahltan Lake sockeye salmon, particularly those annual runs that are late in migrating overall or more consistently the salmon at the latter end of the run period when water levels decline in August near the latter portion of the run.

N19-H06 Decheeka Falls Salmon Passage Assessment, Tahltan River (Stikine River Watershed) - DFO - 2019 Report

N19-H06 Tahltan River Decheeka Falls Preliminary Fish Passage Assessment - Northwest Hydraulics - 2019 Report