Clark County revises stormwater rules




Clark County’s rules curbing stormwater pollution now include provisions required by a June federal court decision.

Clark County commissioners on Tuesday unanimously voted to make permanent the temporary changes adopted immediately after the court’s ruling that the county violated the Clean Water Act from 2008 to 2011.

“The previous board (of commissioners) attempted to find alternate ways to satisfy the dictates of the Department of Ecology,” Commissioner David Madore said. “At this point, we just need to comply.”

In 2008, the county refused to adopt state standards for managing polluted runoff, dismissing them as an unreasonable burden to place on private developers.

In 2011, U.S. District Judge Ronald B. Leighton issued an injunction against Clark County, ordering it to follow state default stormwater requirements that newly developed land drain as slowly as it did prior to Euro-American settlement.

At the time, the county was defending its stormwater plan in the state courts, a fight it ultimately lost.

Stormwater runoff is federally regulated as a major source of water pollution. It contains toxic metals, oil, grease, pesticides, herbicides, bacteria and nutrients that run off buildings and pavement into streams, degrading water quality and killing marine life.

Water flow key

To meet the state standard, computer models are used to determine how slowly land drained prior to Euro-American settlement. Back then, 95 percent of the county was forested, and the remaining land was prairie.

Under the county’s rejected plan, the developer merely had to ensure that on-site flow conditions did not change, with the county making up the difference between that and the pre-settlement standard by restoring flow conditions elsewhere in the same water resource inventory area. The county’s plan was deemed insufficient under federal and state clean water laws.

The county ordinance now requires water flows to match what would have occurred on “historic, forested land cover unless reasonable historic information is provided that indicates the site was prairie prior to settlement.”