Protecting Washington state’s natural resources has been a political issue as much as an environmental one.

But not anymore.

State lawmakers want cities to pay more attention to science when protecting critical areas such as wetlands.

That’s why the state is requiring cities to update their critical areas codes to include "best available science" in determining buffers for streams, wetlands and steep slopes. It must be done by the end of the year for cities in the Puget Sound area.

Cities in south Snohomish County have set buffers for wetlands, for example, that range from 25 to 100 feet. But the state is recommending 100- to 300-foot buffers, based on scientific studies.

Mill Creek planning manager Tom Rogers said politics has played a major role in the past.

"Generally, it’s been the other way around, and development has had a bigger role, and it’s been more of a horse trade back and forth," he said. "It costs a lot to have big buffers, and in the past (setting buffers) has been more of a political compromise."

Now jurisdictions are struggling with what "best available science" means.

In urban south Snohomish County where cities are more than 95 percent built out, most waterways are in culverts and many wetlands are so degraded that restoring them would be practically impossible.

"With ‘best available science,’ the state recommends large buffers to protect wetlands, streams and steep slopes," said Bill Franz, Lynnwood’s public works director. "But at the same time, studies have shown, once an area becomes urbanized, large buffers won’t necessarily restore a degraded wetland."

Lynnwood is pulling together a task force of residents, developers and environmentalists to evaluate the issue. And at 7 p.m. Wednesday, the Pilchuck Audubon Society will sponsor a community workshop at the Lynnwood Public Library on critical areas and changes recommended by the state.

"We are in favor of larger buffers for protecting wildlife habitat and are holding this workshop to let people in the south county area know how they can get involved," said Susie Schaefer, program chairwoman with the Pilchuck Audubon Society.

In Mountlake Terrace, the city hired a consultant and had an open house to get public response. The city’s planning commission will tackle the issue on Monday.

Currently, Mountlake Terrace requires 25-foot buffers for streams and 50-foot buffers for wetlands.

"It’s one thing to say in a rural county area where you’ve got many acres of untouched land, you need 300-foot buffers there. It’s another thing entirely when you’re already 95 percent built out, with much lower buffers to begin with, and there’s the issue of fairness to think about and property rights," said Shane Hope of the Mountlake Terrace Planning Department.

Edmonds has selected a consultant to help with a projected $100,000 plan to rewrite the city’s critical areas regulation, planning manager Rob Chave said. Planning workshops are set for spring, and public hearings will occur in the fall.

Mill Creek has budgeted $70,000 for updating its critical areas ordinance, and has received $25,500 in state grants. It anticipates releasing a draft of the rewritten ordinance for public comment sometime this summer and holding a public hearing before the city’s planning commission this fall.

In Mukilteo, "We are almost all built out," planning director Heather McCartney said.

Right now, the city requires buffers of 75 feet to 100 feet. The state recommends up to 200 feet for the type of wetlands in Mukilteo.

The city has hired two consultants and has spent more than $58,000 rewriting its code. The planning commission will tackle the issue on March 18.

"The recommendations we are making (to the planning commission) are going to be less than what the state wants, because in an urban area it doesn’t make a lot of sense" to have such large buffers, McCartney said.

Doug Peters, senior planner with the state’s growth management services division, said the Growth Management Act does not require cities to completely restore built-out areas.

"They aren’t being required to restore things to the way they were," he said.

Reporter Pam Brice: 425-339-3439 or pbrice@heraldnet.com.