19-058 Corps, Walla Walla County to provide Mill Creek GI Study progress update May 30

Published May 21, 2019

The U.S. Army Corps of Engineers, Walla Walla District (Corps), and Walla Walla County (county) invite the public to attend a progress-update presentation about the Mill Creek General Investigation Feasibility Study (study) on Thursday, May 30, from 5:30 p.m. to 7 p.m. at the Courtyard by Marriott, located at 550 West Rose Street in Walla Walla, Washington.

The presentation will begin at 5:30 p.m., with time afterward for questions.

The Corps and county are partnering on the GI study to identify vulnerabilities of the 1938 Mill Creek Flood Control Project, develop and evaluate potential alternatives, and recommend a plan to improve system performance, reliability and sustainability, ultimately reducing flood risk to the City of Walla Walla and surrounding communities. For more general information about the Mill Creek GI Study, visit https://www.nww.usace.army.mil/MillCreekGI/.

The Corps and county held a public scoping meeting on Nov. 1, 2018, to gather ideas and concerns for the study team to consider when developing potential alternatives to be evaluated.

“Since that meeting, the team’s examination of a broad, initial array of potential alternatives narrowed things down to just a few that clearly have potential to solve the Mill Creek system’s existing problems and meet our goals for improved performance and reliability,” said Study Project Manager Alex Colter. “Equally important, these alternatives have the potential to meet the cost-benefit ratio thresholds necessary for federal interest in a potential flood-risk-management improvement project.”  

In order for the Corps to demonstrate a viable project, the final recommended alternative must have a benefit-to-cost ratio of 1.0 or more, therefore confirming a likely federal interest, Colter explained.

“It’s important to understand that the overarching goal of this federal project is to contribute to National Economic Development (NED), which represents increases in the net value of the national output of goods and services,” he said. “An optimized NED plan is the default selected plan unless a Locally Preferred Plan (LPP) is developed and selected. An LPP with justifiable costs and benefits can be considered, but others (non-federal) must bear the additional costs.”

The county continues working with their Mill Creek Coalition partners on identifying elements for an LPP. Once the flood-risk-management NED plan is selected, the LPP can be formally developed. The study team is on schedule to have an NED plan selected during late-autumn 2019.

“We still have a lot of research and analysis to do before we have a tentatively selected NED plan identified,” said Colter. “Come out for the May 30 study update – we’ve made a lot of progress that we’re excited to share.”

Public Affairs Office

Release no. 19-058