News for those who live, work and play in the Santiam Canyon

Snowpack, recent rains boost Detroit Lake

A strong snowpack year and some welcome spring rain and snow have given a lift to prospects for the lake level at Detroit Lake, but U.S. Army Corps of Engineer officials still warn that “this will be a tough water year.”

Year-to-date precipitation across the Willamette River basin was 96% of normal as of April 21, with the snowpack at 128% of median, Corps officials said.

But the water produced by those numbers must play out over the entire 13-dam Willamette Valley Project, which will be a challenge, said Erik Petersen, operations project manager.

“Snowmelt helps keep reservoir elevations up in the summer if it lasts and matches outflows,” he said, “but it only accounts for less than 10% of the system’s storage.

 “Extended drought conditions, variability of snowpack in the Cascades, and modified dam operations to support downstream passage of juvenile salmon are impacting refill of the system. This will be a tough water year with less overall system storage, limiting our supplies to augment for water quality and fisheries habitat downstream during the summer and fall.”

Chris Gaylord, public affairs specialist with the Corps, told The Canyon Weekly that Detroit Lake is just 3 feet below “rule curve,” which is the authorized maximum elevation on a given day to balance flood risk management and storage for other authorized purposes, such as recreation, hydropower, and irrigation supply. 

Gaylord added that the recent precipitation likely means that Detroit will hit the rule curve sometime next week.

“Conditions have certainly taken an optimistic turn since earlier this month, with the recent rainfall and late-season snow,” he said. “It really demonstrates how quickly conditions can change across this system.”

The other key figure to note for Detroit and the system’s other reservoirs is ”maximum conservation.” That’s the fill level the Corps shoots for as it heads into “conservation” season. At Detroit, Gaylord said, that usually happens in early to mid May. This year, however, the Corps will stop the fill at 5 feet below maximum as part of a risk reduction program aimed at minimizing the chance of buckling in the dam’s spillway gates.

Gaylord calls the approach “a temporary measure to address the risk while we conduct a more in-depth structural analysis and further evaluation to determine if the gates need a permanent modification and, if so, what that would look like and how we would accomplish it.”

What happens to the lake level later this summer remains to be seen, Petersen said.

“Diminished water storage during the summer months means that reservoirs with more water may drop in elevation faster than normal as the Corps draws from them to meet downstream needs,” he said.

And the more rain and even snow that hits in the spring could help limit how widespread those downstream needs are, Corps officials said.

Previous Article

Santiam Medical Clinic aims to help patients with more than healthcare

Next Article

Appeals court throws out timber counties lawsuit

You might be interested in …

Linn County Sheriff

Linn County Sheriff’s Office Log: Aug. 21 – 25

Aug. 21 Trespass, 9:13 a.m., Stayton-Scio Road, Scio. Deputies attempted to locate trespassers. Suspicious Circumstances, 9:28 a.m., SE Evergreen Avenue, Idanha. Deputies received information regarding suspicious activity. Extra Patrol, 10:06 a.m., NW Second Avenue, Mill […]