In Washington state’s fruit-growing regions, frost ponds serve a serious purpose. They ensure a source of standby water for the mist that protects budding trees from frost damage.

That’s good for the trees, but if the dams that hold the frost ponds in place fail, it’s bad for people and property downstream.

The law attempts to safeguard those in the path of danger by setting construction and safety standards that dams, whether for frost ponds or other purposes, must meet. Unfortunately, many businesses and individuals ignore the legal process when they construct dams.

In recent years, five such unpermitted dams have failed in Washington state. None was as tragic as the 2006 washout of the Kaloko Dam in Kauai, Hawaii, where seven people died, but the Washington incidents did cause hundreds of thousands of dollars in property damage.

At least one of the dams had been in place for 30 years with none of the permits or inspections prescribed by state law. It failed within days of being refilled after a contractor – also working without engineering, permits or inspections – had replaced an outlet pipe.

Inspired largely by the series of failures, the Washington state Department of Ecology took a closer look at the situation. In about three months, an intern studying a statewide set of aerial photos had identified what appeared to be 594 unpermitted dams with three or more homes downstream, making them “high hazard.”

After closer investigation, they determined 96 are actually high-hazard and 30 of those – including one 14 miles west of Spokane – pose major risks. They’re now bringing regulatory pressure on the dam owners to get voluntary compliance if they can, or take harsher enforcement steps if they have to.

To turn their attention to those previously unscrutinized dams, however, Ecology inspectors had to put on hold the routine inspection work they perform on nearly 1,000 dams that were built according to all the legal requirements. The department has asked, with Gov. Chris Gregoire’s concurrence, for the Legislature to fund two more inspectors.

Even in a time of severe fiscal pressure, the request makes sense, both because of the public-safety implications and because the inspectors would pay for themselves through fines and fees.

In the meantime, someone high in the Department of Ecology should look into how nearly 600 dams, some of them 30 or 40 feet high, could have been built in the state without coming to the agency’s attention.

Moreover, the Department of Ecology had made a similar discovery in the 1980s when a federal grant underwrote an aerial search that uncovered 200 unpermitted dams. Now, a quarter century later, the discovery of 600 more is painfully familiar.

Ecology needs its two self-supporting inspectors. In return it needs to show the public it can prevent the problem from getting out of control again.