The Washington State Department of Ecology completed a statewide dam inspection campaign recently and has ordered the immediate repairs of at least seven dams in the Sunnyside area.
In the past two months Ecology has inspected 95 private dams and reservoirs built without permits in the state. The effort was enlisted to help prevent flooding in case a dam ever breached its banks. The dams are often used in farming as frost control ponds or to store the waste from large dairy farms.
"This was the largest dam safety inspection campaign we've done since the Nisqually earthquake of 2001," said Doug Johnson, Ecology's dam safety supervisor. "After the Nisqually event, more than 300 dams received at least cursory inspection for earthquake damage."
Johnson said the six or seven dams above Sunnyside are just north of the Roza Canal and are owned by Evans Fruit Company, Pride Packing Company and Avalon Fruit.
Recent media reports about the dams stated the city of Sunnyside could be wiped out if there was a breach in the dams, something Johnson said just wasn't true.
"Sunnyside wouldn't get wiped-out but a breach could cause two to three feet of flooding in the lower lying areas of the city," Johnson said.
Reducing any damage further, Johnson said, is the fact that Avalon Fruit has drained its dams above Sunnyside. Evans Fruit Company and Pride Packing Company have drawn down their dams enough to reduce any risk.
The companies will now begin work on designing spillways to protect against erosion of the soil to keep the dams' banks intact.
"Our goal is to get them ready before spring when the dams will be filled," Johnson said. "If they aren't fixed by April then Ecology will not allow the dams to be filled."
The dams are unpermitted but Johnson said the owners will not be fined for that discrepancy. The owners of the dams will have to pay $1,400 to get permits for the dams, and at least $814 to pay for an inspection, something that will be an annual charge, and any other costs associated with bringing the dams into compliance with the law.
Johnson also stressed there is no immediate danger now.
Johnson said there are other dams in the area that are unpermitted but Ecology believes these dams to be at a low to moderate risk and will be dealt with at a later time.