Officials to inspect unlicensed dams
Structures listed as potential hazards
Officials compiling a list of unlicensed dams in Washington have spotted 14 in Spokane County that are “potentially hazardous.”
That preliminary assessment is based on “a very simple question: Are there homes downstream” that could be damaged if the dam failed, said Doug Johnson, dam safety supervisor for the state Department of Ecology.
So far, Ecology Department officials scanning aerial photos have spotted 594 unlicensed dams – those built without permits. But on-site visits are needed to determine the dams’ condition, and whether they fall within the agency’s authority. Ecology regulates dams that hold back 10 or more acre-feet of water. That’s equivalent to 3.26 million gallons, or a football field flooded to a depth of eight feet.
Until those reviews are done, agency officials say they won’t release the list.
Unlicensed dams typically do not block year-around streams, Johnson said. More often, they’re designed to hold back storm water in a natural drainage, for recreational or agricultural uses, or aesthetics.
Also on the statewide list are more than 100 dairy waste ponds and sewage lagoons, Johnson said.
Those deemed “potentially hazardous” include 41 dams in Yakima County – more than anywhere else in the state. They are primarily reservoirs created for times when orchardists need a lot of water very quickly, to spray a mist for frost control. Five such Yakima County dams have failed in recent years, prompting the current inventory work.
Grant and Whatcom counties each have 22 unlicensed dams,
Ecology is giving landowners until Sept. 1 to report any unlicensed dams without facing fines for failing to obtain construction permits.
Once reported, dams become subject to safety inspections. Owners of dams deemed deficient may be told to hire an engineer to design repairs, and those that refuse can face fines of up to $5,000 a day.
Very rarely, the state mandates that a dam be drained and removed. “The last one we had was over in Okanogan County and that was back in the late ’80s,” Johnson said.
For more information, go to www.ecy.wa.gov.