A word of advice to folks living north of 22nd Street NE in Auburn, Washington—buy some flood insurance. Those residents and about 20,000 others in southern King County could find four to ten feet of water in their homes this flood season thanks to a weakness in the nearby Howard Hanson Dam, according to the Seattle Post-Intelligencer.

The dam, which was built in 1962, developed issues during flooding in January. Although the Army Corps of Engineers, which owns and operates the dam, is installing an $8 million temporary “grout curtain” to shore up leaking, the dam’s lessened capacity could force them to release flood runoff that could inundate areas of Kent, Renton, Auburn, and Tukwila, according to the Kent Reporter.

Although county officials are doing what they can to mitigate worst-case scenarios—including making a preemptive declaration of emergency Wednesday—they’ll have to live with the situation for about five years, until a permanent fix for the dam can be planned and funded, according to the Reporter article. While preparing for possible flooding is straining the already dry county coffers, an actual flood could cost $3 billion in damages and $46 million dollars a day, according to the Post-Intelligencer.

"Right now King County government is faced with multiple challenges," County Councilman Bob Ferguson was quoted as saying in the Post-Intelligencer. "But I think it's fair to say all those challenges pale compared to the impact of a breach or a significant impact of Howard Hanson Dam."

Unfortunately, King County is far from the only local government with a significantly damaged dam in their back yard. Across the nation, “more than 2,000 dams near population centers are in need of repair,” according to a recent article in Wired Science. A report by the American Society of Civil Engineers (ASCE) estimates it would cost $16 billion to fix dams rated as a high hazard—and that doesn’t include the money necessary to make sure dams stay in tip-top shape.

“With the huge number of dams getting older every day, it’s becoming a bigger and bigger problem,” ASCE Deputy Executive Director Larry Roth told Wired. “The policing of maintenance and filing of inspection records is relatively haphazard, not because of lack of focus or knowledge of significance, but they just don’t have the monetary resources to do it.”

Adding to those issues are increased development in overflow zones and a hodgepodge of state, federal, and private ownership, and in some cases, no ownership at all. The end effect is a collection of life-threatening dams with spotty or nonexistent maintenance.

“They are not being maintained and they are getting older and the conditions around the dams are often changing,” Roth said in the Wired article.

The ASCE report, part of its Report Card for America’s Infrastructure series, recommends including dam failure inundation mapping as part of the National Flood Insurance Program, developing emergency action plans for high hazard dams, and establishing adequate funding for repair and maintenance of government and privately owned dams.