The entire uplands areas from Tamihi Creek upstream to and including Slesse Creek is pretty much unstable and comprised of clay deposits in the hillsides. A drive along the Bench Road, south to north, will show these areas very well. These unstable areas have caused disruptions to sports fisheries in the past, and will continue to do so in the future as nothing short of rip rapping the entire stretch will stop these natural slumping hillside occurrences.
The Chilliwack River Action Committee and its many partners spent hundred's of thousands of dollars addressing these slides in the past, sadly with very little positive results. All it takes is a major rainfall/snow melt event to bring these clay areas along side the river, creating extremely turbid water.
These events are another reason why the off channel habitat areas created in the upper and more recently in the lower river are so important to spawning and rearing success of salmonids in the C-V.
If there is a positive to this it is that a few fish get upstream from this turbid water into the area closed to fishing during these non angler days and eventually spawn.