A number of landslides that occurred during or after a severe storm event on November 15, 2006, caused severe impacts to fish habitat in the Sproat Lake watershed. Fish and fish habitat in an un-named tributary to Two Rivers Arm of Sproat Lake, located at 7.0 km on the Sterling Arm Mainline, was one of the most severely impacted areas. The landslide buried the entire fish bearing portion of the stream, which stretches 500 m upstream from the creek mouth at Sproat Lake (Wright, 2000). It is likely all juvenile fish [coho (Oncorhynchus kisutch) and cutthroat (Oncorhynchus clarki)], spawning sockeye (Oncorhynchus nerka) and coho, and incubating eggs were destroyed by the slide. The greatest impact to fish production was likely the loss of high value sockeye beach spawning habitat surrounding the creek delta. Williams (2006), Askin (2007a), and Campbell and Millard (2007), inspected the slide and concluded that more material is still available upslope and will likely be transported downstream in the future. To protect the critical beach spawning habitat a prescription was developed to trap future materials that could be transported downstream before it reached the critical beach spawning habitat in Sproat Lake. The prescribed works were completed in two phases in 2007.
On December 3, 2007 a major rain on snow event mobilized a significant volume of sediment, which completely in filled the entire storage basin to the weir crest (Photo 1 and 2). To ensure that the upper storage basin continues to function as a sediment and debris trap and continues to provide effective protection for the critical sockeye beach spawning habitat in Sproat Lake A work plan was created and submitted to Forest Investment Account (FIA). The plan submitted was to remove the material stored in the catch basin in preparation for the fall and winter storms of 2008 and 2009. The project received approval and funding from FIA to clean out the basin during the summer of 2008.