Stillaguamish Basin Water Management Rule

Stillaguamish Water Reservations 2015 Report

The Stillaguamish Instream Flow Rule established reservations of water for specific out-of-stream uses that are not subject to instream flows.  The rule created two reservations of limited water supplies for different purposes of use:

The reservations apply from September 26, 2005 forward since that was the date the rule became effective.

This report summarizes water uses under the reservations defined in WAC 173-505 from September 26, 2005 through December 31, 2015.

Water management rule effective September 26, 2005

The Department of Ecology (Ecology) adopted a water management program that will guide water management decisions in the Stillaguamish River basin from September 26, 2005 into the future.  It includes setting protective stream-flows for the Stillaguamish basin in Snohomish and Skagit Counties.  The rule was adopted on August 26, 2005 and became effective September 26, 2005:

Elements of the rule

The rule does not affect:

Instream flows

State law requires Ecology to set “instream” flows by rule that are designed to protect the resources that depend on flowing water – including fish, wildlife, recreation, navigation, water quality, livestock watering and aesthetic needs.

While instream flows are established through the state rule-making process, setting them does not guarantee that water will always be in a stream at the time it is needed the most.  All future permits for water rights that will reduce the flow of water in instream flow protected water bodies must be limited so that water can only be taken when the actual flow exceeds the minimum instream flow.

The rule set instream flows in the Stillaguamish basin to protect flows for fish rearing and spawning. Ecology and the Department of Fish and Wildlife worked in close consultation with the Tulalip and Stillaguamish Indian Tribes and local governments when developing the rule.

Small domestic ground water withdrawals

A reservation of a limited quantity of water was made available to serve domestic needs and the human health requirements of businesses.  The reserved water is not subject to instream flows.  The quantity of water reserved does not significantly impact fish habitat.

Other conditions for use of the reservation include:

Water for livestock

A reservation of one cubic foot per second (cfs) of surface water and 20 acre-feet per year of ground water are available for future livestock watering without requiring a water-right permit.

New water rights, closures

New water rights that are not part of the domestic or livestock reserve must be subject to the instream flows.  Most streams with limited flows are closed to future water uses. Therefore, new surface or ground water permits will only be considered in one of the following situations:

Future water withdrawals

Total future water allocations will be limited to protect the benefits of high stream flows.  High flows provide critical ecological functions for channel maintenance.  To protect the frequency and duration of high flows, Ecology established a maximum amount of water that can be withdrawn from streams when flows are above levels set under the instream flow rule.

Overview of Basin

The Stillaguamish River is the fifth largest tributary to the Puget Sound. The watershed is divided into three large sub-basins—the North Fork, the South Fork, and the lower mainstem. The three largest tributaries include: Pilchuck Creek, Deer Creek, and Canyon Creek.

Over 76% of the land cover is in forestry. Agricultural farms and dairies are concentrated in the valley bottoms along the mainstem and larger tributaries. Rural residential development and hobby farms are increasing throughout all rural areas of the watershed.

The Stillaguamish system supports five species of salmon—Chinook (listed as threatened under ESA), Coho (depressed population), pink, chum, and sockeye; and three species of anadromous trout, steelhead, bull (listed as threatened under ESA) and cutthroat.

There are many habitat limiting factors (e.g., temperature, sediment, altered streamflows, loss of estuarine habitat) negatively affecting the salmon population and their ecosystem. Most factors are result of upland forestry activities.

For additional information:


Kellie Gillingham
Phone: 425-649-7186