Disaster was averted.
The Mill Creek Flood Control Project, completed in 1942 during World War II, worked perfectly last week as heavy rain and warm temperatures melted mountain snow, causing a flood of historic proportion.
“Everything worked as designed,” said Justin Stegall, the Mill Creek project manager for the U.S. Army Corps of Engineers, which has overseen the Bennington Lake reservoir and the Mill Creek channel since the Corps designed and built the flood control system.
Most of Walla Walla, including downtown, was spared from the rushing water that couldn’t be absorbed into the already saturated ground. That, however, doesn’t mean Corps’ employees and the folks in the Walla Walla Valley didn’t have some extremely tense moments.
The water level at the reservoir was at about 80 percent of capacity. If the rain had not subsided last Friday, it’s likely evacuation orders would have been given in case more water had to be released from the reservoir into the channel, said Shawn Nelson, the Corps’ chief of hydraulics and hydrology.
Thankfully, the rain stopped.
Last week’s flood is now considered one of the worst three in the Valley’s recorded history.
The first was in 1931. Mill Creek flooded the entire downtown area and much of the city. The streets were rivers and homes — and businesses — were engulfed by water. This spawned the Mill Creek Flood Control Project, which was designed in the 1930s and finished the next decade.
The second flood came in 1996 when warm temperatures melted the snow, but the ground was so frozen the water had nowhere to go.
The reservoir was near 90 percent capacity that year, but it held. The flood took a toll, just as it did this year, but without the reservoir and channel, it would have been far, far worse.
The only thing certain about the future is that, at some point, there will be another major flood in the greater Walla Walla Valley.
And this is why the current, ongoing effort to upgrading the deteriorating flood control channel must come to fruition.
In June of 2018, Congress authorized a three-year study of what needs to be done to upgrade the Mill Creek Flood Control project. It was approved only after local officials and citizens lobbied Congress to show the need.
While the Mill Creek channel is structurally sound today — as evidenced by last week’s success — it’s 78-year-old bones are creaking. The signs of wear are evident. Components of the flood-control system have degraded over time. We simply don’t know how long it will remain reliable nor how long the integrity of the bridges over the channel will hold.
When the study is completed next year, this community must keep the pressure on Congress to fund critical upgrades.
Our future depends on it.