Skagit River basin projects

In 2001, we adopted Chapter 173-503 WAC, which established instream flow levels to help protect the ecosystem of the Skagit River. The rule protects adequate water in the river for healthy salmon runs, good water quality, and recreational activities, as required by state law. It also protects existing water rights.

Instream flows are like a water right for the river. Under Washington water law, new uses of water (in this case, those started after the effective date of the rule) can't impact existing water rights, no matter how small that impact may be. This includes any impacts to streamflows whenever they drop below the protected instream flow levels. Therefore, there are limits on new water uses of any size, including permit-exempt wells, in the Skagit River basin.

We are actively pursuing a number of projects to find water supply solutions for property owners in the Skagit River basin. We recently notified Skagit County about a new water availability zone in the Bayview area. As groundwater in this area flows to marine waters, there are no impacts on the protected Skagit River, so no mitigation is necessary.

Is your property affected?

Here's how to determine if your property is affected by the Skagit River basin instream flow rule:

  1. Open the map
  2. Click on “Planning and Development” on the left
  3. Click on “Skagit Instream Flow rule Area 4”
  4. Go to “Search” in the lower left and enter your information. (If using your name, put your last name first)


The Skagit River basin instream resources protection program rule (WAC 173-503) went into effect on April 14, 2001. It was the culmination of an open public process that began in 1994 with research on the Cultus Mountain tributaries of the Skagit River. These early efforts to evaluate estimated future out-of-stream water uses and their impacts on fish were led by Skagit PUD. Since then, research and planning for Skagit River basin water has been a multi-organization effort, which includes:

  • City of Anacortes
  • Skagit County
  • Skagit PUD
  • Swinomish Indian Tribal Community and the Sauk-Suiattle Indian Tribe (known collectively as the Skagit System Cooperative)
  • Upper Skagit Indian Tribe
  • Washington Department of Ecology
  • Washington Department of Fish and Wildlife (WDFW)
  • The general public and interested stakeholders

In 2006, the rule was amended in response to a Skagit County lawsuit claiming that the rule did not provide adequate guarantees of future water for Skagit property owners. The amendment established reservations of surface and groundwater not subject to the instream flows for future out-of-stream uses. The sizes of the reservations were limited to amounts that WDFW's and our fish biologists determined would not substantially harm long-term fish survival. The reservations provided uninterruptible (year-round) water supplies for new agricultural, residential, commercial/industrial, and livestock uses, distributed among 25 subbasins. They were effective as of the original date of the rule, April 14, 2001. The Swinomish Tribe challenged the reservations on the grounds that they compromised adequate protection for fish.

Supreme court decision and its impact on water use in the Skagit basin

On Oct. 3, 2013, the Washington State Supreme Court ruled in Swinomish Indian Tribal Community v. Department of Ecology (pdf) that we exceeded our authority in establishing the water reservations. The rule reverted to its original text from 2001. Without reservations, year-round water uses that began after the rule took effect in 2001 can be interrupted when streamflows are below the regulatory instream flow levels.

Note: The Swinomish ruling does not affect water uses established before April 14, 2001, or customers of public water systems.

2001 – 2013 Skagit groundwater uses are secure while water supply solutions are developed

The Swinomish ruling created legal uncertainty for the water use of about 480 homes and businesses that have relied on the water reservations since adoption of the 2001 rule. Since the court decision, we have been looking for water supply solutions for those homes and businesses affected by the ruling. The Swinomish Tribe agrees existing water uses should not be curtailed while we are developing mitigation.