Mill Creek Flood Control Project


Following a devastating flood in 1931, the Army Corps of Engineers channelized a free-flowing stream known as Mill Creek, which flows through downtown Walla Walla, Washington. The Mill Creek Flood Control Channel in Walla Walla, Washington has successfully mitigated flooding issues since then, but after decades of wear and tear, the Channel’s infrastructure is crumbling and high water levels are once again threatening the city. The Mill Creek Flood Channel runs underneath or adjacent to historic buildings, businesses, and public facilities in the downtown Walla Walla area, protecting over 23,000 Washingtonians and almost 10,000 structures with a property value of $3 billion.

If the Channel continues to deteriorate, an inevitable collapse would result in the significant loss of property, potential loss of life, and flooding of critical facilities including hospitals, schools, and fire stations. Contributing to the problem is a water management decision by the Corps of Engineers necessitating the release of more water from Bennington Lake into Mill Creek during periods of high water due to reduced storage capacity in the Lake itself. The Mill Creek Channel received a “minimally acceptable” rating during a periodic inspection in 2010, leading Walla Walla County, the City of Walla Walla, the Port of Walla Walla, and the Downtown Walla Walla Foundation to form the Mill Creek Coalition in 2013. This coalition of interests partnered with Summit Strategies to seek funding from the US Army Corps of Engineers for a General Investigation (GI) Study to evaluate Mill Creek’s safety, viability, and need for stabilizing improvements.

Summit Solution

Alongside the Mill Creek Coalition, Summit Strategies worked with the Washington State Congressional delegation to strongly advocate for a GI Study of the Mill Creek Flood Control Channel. After advocating for increased Corps funding and Congressional directives to initiate new flood control projects by the Corps of Engineers, it was announced that Walla Walla’s Mill Creek Flood Control project would be included in the US Army Corps of Engineers 2018 Work Plan as one of this year’s six “newstarts” nationwide.

Summit’s coordinated lobbying effort involved:

  • Coalition Building

  • Congressional Fly-Ins

  • Regular meetings with officials from the US Army Corps of Engineers, the Office of Management and Budget, Members of Congress, and key Congressional Committees 


On June 8, 2018, the US Army Corps of Engineers announced that the Mill Creek Project would be included in its 2018 Work Plan as one of six new projects initiated in Federal Fiscal Year 2018. Achieving “newstart” status is a significant accomplishment and could not have been done without strong advocacy efforts by Senators Patty Murray and Maria Cantwell and Representative Cathy McMorris Rodgers. Over the next three years, this new GI study will examine the Mill Creek Flood Channel’s risks and identify ways to address its infrastructure problems.