Washington Water Trust

Working to restore our state's rivers and streams.

Mill Creek

WHEREMill Creek is a tributary to the Walla Walla River, which flows into the Columbia River.
WHATThe Mill Creek project combines instream flow restoration with riparian habitat restoration through CREP for a comprehensive land and water conservation project.
WHOWWT partnered with the Maxsons, Department of Ecology, Bonneville Power Administration, National Fish & Wildlife Foundation, Walla Walla County Conservation District
WHYTo help rewater 31 miles of stream and support passage for threatened summer steelhead and bull trout to quality upstream habitat.
WHENOngoing since 2004.
Mill Creek, a tributary of the Walla Walla River, was identified under the national water quality list as having insufficient stream flow and high water temperatures, which severely limit access for both summer steelhead and bull trout upstream habitat.

Because the Maxson family was committed to habitat restoration on their property, they enrolled in the Conservation Reserve Enhancement Program (CREP), which helped them return several acres of their lands to natural habitat that would support deer and upland bird populations. WWT worked with the Maxons to place their water rights associated with CREP riparian buffers into the Trust Water Program where they are protected for instream flows. As a result, the family combines flow restoration with riparian habitat restoration through CREP, while continuing to support a horse boarding/training facility and a variety of crops on their property.

With collaborative efforts, this project created multiple benefits in the Walla Walla Basin. Summer steelhead and bull trout in the basin are listed as threatened under the Endangered Species Act. High stream temperatures and insufficient stream flows in Mill Creek have severely limited the accessibility of both of these species to quality habitat upstream, and their ability to use the lower reaches of Mill Creek for spawning and rearing. Mill Creek is used primarily as a migration corridor for both adult and juvenile steelhead, but supports spawning and rearing as well. Bull trout use the creek for migration, but winter over when stream flows are sufficient. Spring Chinook, extinct since the 1950s are being introduced by the Confederated Tribes of the Umatilla Indian Reservation and may eventually use Mill Creek as a passage corridor or for winter rearing.