March 31, 1931 — Record flood in Mill Creek causes more than $1 million in damage ($16.3 million today when adjusted for inflation).
Jan. 9, 1937 — Movement starts to have Congress include flood control project in general flood control proposal appropriations.
Oct. 31, 1937 — Sen. Homer T. Bone and Congressman Knute Hill visit Walla Walla, leave promising to help get appropriations for flood control project.
April 9, 1938 — Virgil B. Bennington, president of the Walla Walla Chamber of Commerce, appears before the House flood control committee to make case for Mill Creek Flood Control Project.
June 29, 1938 — President Roosevelt signs omnibus flood control measure, but no appropriation is made at that time.
June 29, 1939 — After approval by House and Senate, President Roosevelt signs bill making $1 million available for the project.
May 9, 1940 — Bids opened for contract to construct project. Parker-Schram of Portland and Smith of San Francisco submit joint low bid of $905,570 ($14,787,958 today when adjusted for inflation).
January 1942 — Project declared operational for flood risk reduction. However, channel through town was not the concrete structure in place today.
1947 — Report submitted to complete intermittent WPA (Works Project Administration) work which had been done and pave the bottom of a formal channel through town. This was approved and the work accomplished in 1948 at a cost of $600,000 ($9,798,000 today when adjusted for inflation). The combination of the reservoir and the channel through town affords protection for a flood equal to that of 1931, or about 6,000 cubic feet per second. The reservoir and downstream channel projects were both constructed by the Portland District.
1992 — The lake behind the dam formally named for Virgil B. Bennington with the passage of the Water Resources Development Act that year.
February 1996 — Major flood event matching 1931 flood.
(Source: U.S. Army Corps of Engineers and Union-Bulletin files)
WALLA WALLA — As the system that keeps Mill Creek from flooding Walla Walla approaches its 75th birthday, some folks are starting to seek an answer to “what’s next?”
Since July, a nascent coalition of public and private interests has been meeting to explore how to tackle what all involved agree fits the definition of a long-term project. That is how to design, build and pay for the work needed to ensure the Mill Creek Flood Reduction Project continues working well into the 21st century.
“Seventy-two years have gone by and we need to look at the channel to make it safe for the next generation,” said Mark Kajita, Walla Walla Downtown Foundation board member. “It’s been a number of years since people have taken a holistic view of the issue.”
All involved emphasize the channel is in no danger of failing, a view backed up by results of periodic inspections by the U.S. Army Corps of Engineers.
Although those inspections have identified deficiencies in the system, the project is performing well based on its age and is rated as “minimally acceptable,” which makes it eligible for federal assistance in the event of damage by a flood event.
At present, the Mill Creek Coalition consists of Walla Walla County, city of Walla Walla, Port of Walla Walla and the Downtown Walla Walla Foundation. Congresswoman Cathy McMorris Rodgers’ office has also been involved.
The coalition came together following the presentation of a study by Corps representatives at a July 8 meeting of the county commissioners.
The Planning Assistance to States study was done at the request of the county commissioners, who entered into a partnership with the Corps in August 2011, said Cindy Boen, plan formulation section chief for the Corps’ Walla Walla District Office. The study cost $37,342, of which half was paid for with federal funds and half by county funds.
According to the study, although the project is performing well, its maintenance costs will increase over time. At present, the project has an annual maintenance budget of $50,000 paid for by a property tax levy on landowners in the Mill Creek Flood Control District.
The study showed the maintenance costs are well worth the expense. An economic analysis done by the planners showed the average annual flood damage prevented by Bennington Lake and the Mill Creek channel is $595,000.
A “single event failure” of the channel would cause an estimated $177 million in damages, the study said.
While the project has not reached the end of its design life, the study concluded it may have extensive hidden deterioration, especially along the concrete channel and that erosion damage is accumulating on the stabilizers in the channel. Minor repairs are also needed in multiple locations along the levees.
The study’s recommendations call for a more aggressive maintenance program to preserve the channel’s minimally acceptable rating, along with other steps such as updating the county’s emergency response plan and public education. But it also urged stakeholders “to consider a comprehensive, long-term fix for the future.”
At the July 8 meeting, Randy Glaeser, county public works director and former commander of the Walla Walla District summed up the issue in other words.
“It’s OK today and maybe for the next five years, but some day it’s not going to be fine,” he said. “The most important thing is to understand where we’re at and look at potential options to move ahead.”
That next step in the process will be a comprehensive planning study in partnership with the Corps.
Jim Kuntz, Port of Walla Walla executive director, said that would involve a two-step approach, the first of which would be a “Section 216 study” authorized by the Flood Control Act of 1970. That would act as a precursor to a General Investigation Study, a more comprehensive examination that would require congressional approval for funding.
But moving ahead will require broad-based community support, Kuntz said.
“I see this quite frankly as similar to the U.S. Highway 12 Coalition where a group of citizens come together to identify a long-term solution to a community need,” he said. “We want to ensure the Mill Creek channel retains its capability.
“It works, it functions and there’s no immediate danger,” Kuntz said. “But a progressive community looks 10 to 15 years down the road.”
Andy Porter can be reached at email@example.com or 526-8318.