New research on a small creek in Mason County could shed light on how permit-exempt wells are impacting salmon and tribal treaty harvest rights.

“This research shows that in order to make good land use and water resources decisions, local governments first need to find out how much water is actually available,” said Jeff Dickison, assistant natural resources director for the Squaxin Island Tribe.

Permit-exempt wells had been a way for developers to access water without first determining whether water is available. Last fall the state Supreme Court required local governments, in recognition of senior water rights holders, to first determine water availability before issuing building permits.

“The common use of exempt wells in places like Johns Creek has made them a real – and hard to track – problem in determining water availability,” Dickison said. Johns Creek has been the focus of intense legal wrangling between the Squaxin Island Tribe and the state of Washington in recent years. The tribe sued the state in 2010 asking that they either find out how much water was available in the watershed or impose a moratorium on new wells until the determination can be made.

That debate spurred new research into water resources in the Johns Creek watershed.

According to a new groundwater model developed over seven years, 50 percent of water withdrawals in Johns Creek are from permit-exempt wells. This is well above the assumed statewide average of one percent, which includes large agricultural operations on the east side of the state.

“This model shows that even if exempt well use is small on the statewide scale, it can be massive on creeks that are extremely valuable to tribes,” Dickison said.

Johns Creek has fallen below the state mandated minimum flows for protecting salmon every year for the last ten years. According to the research 0.2 cubic feet per second (cfs) of water is already missing from Johns Creek because of exempt wells and by 2040 this will rise to 0.3 cfs, nearly 10 per cent of the creek flow.

“The future estimate is very conservative because it assumes that there will be no land-use zoning changes in the area in the next few decades,” Dickison said.

The research also found that the state underestimated the number of exempt wells in the watershed by a third. By taking a look at the number of septic systems that were on file, the researchers found over a thousand more wells.

Johns Creek is an important place for coho salmon, which region-wide, have been on a slow downward trend. Unlike other salmon stocks, coho depend heavily on stream habitat because they spend an extra year in freshwater before migrating to the ocean. “Warm summer low flows can be especially hard on coho, which need to find plentiful cool water to survive,” Dickison said.