Snohomish PUD will be providing a whitewater boating opportunity on the Upper Sultan River on Sunday August 8th. Paddlers who plan to attend are asked to register on the Snohomish PUD website. We have been working for the past 3 years to provide this mid-summer opportunity. While we hoped to release a bit more water than the anticipated flow of 500-700 cfs, we agreed to this flow out of an abundance of caution to prevent impacts to fishery resources of the Skykomish River basin. With monitoring during this release, we hope to collect additional information that can inform future summer whitewater boating opportunities on the Sultan River.

Background

When American Whitewater negotiated flows for the Upper Sultan we agreed to two scheduled whitewater releases (these have occurred annually in September and May) and two opportunistic releases each year. The idea with the opportunistic releases was that we could offer whitewater boating opportunities in the fall when rains would bring the river to levels just below a boatable flow and we could supplement that with some water from a whitewater budget to provide a recreational opportunity. In practice, forecasting and scheduling theses events was difficult and we would only get a couple of participants—invariably they would fall on weekdays during the shortest days of the year with little advance notice.

American Whitewater sat down with Snohomish PUD and other members of the Aquatic Resources Committee (American Whitewater is a member) for license implementation to see if we could take our water budget and provide a third scheduled release in lieu of the two opportunistic events. Looking at the timing of various fish runs it appeared we could make this happen in late July or early August and with the support of the Aquatic Resources Committee, we modified the plan accordingly. In 2020 COVID-19 intervened and we were not able to provide any whitewater opportunities given public health guidance limiting group events. Unfortunately the delay in implementation resulted in some loss of institutional knowledge on the decision we collectively made.

We were prepared to make the event happen in 2021 but new questions emerged with respect to timing of a coldwater release at a time when flows on the Skykomish River are low and the potential to attract hatchery Chinook destined for the Wallace Hatchery into the Sultan River. Uncertainty over impacts to rearing juveniles in the Sultan was also raised as a potential issue. After meeting this week, the Aquatic Resources Committee made the decision to proceed forward with the release but in an abundance of caution the PUD will release a reduced flow of 500-700 cfs. The PUD also committed to monitoring to document any evidence of attraction flows or impacts to rearing juveniles. American Whitewater believes there will be a net benefit to these flows in providing a flushing flow for a river channel with a heavily modified flow regime and reduced summer flows; low flows can result in elevated temperatures and build up of organic material and increased biochemical oxygen demand.