Polluted stormwater runoff is one of the biggest obstacles to salmon recovery and the cleanup of Puget Sound.

Scientists have seen adult coho salmon dying within 24 hours of returning to some polluted urban streams in western Washington. In some cases, 60 to 90 percent of the coho are dying before they can spawn.

What’s killing the fish? It’s a poison soup of brake pad dust, oil, gasoline and other pollutants that are washed by rain or melting snow from yards, sidewalks, parking lots and roads, right into our streams and Puget Sound.

We need to stop the pollution from getting into our waters in the first place. Prevention is a lot cheaper and more effective in the long run than trying to clean up waters once they are polluted.

Development has changed the way rainwater runs off here in Western Washington. Our watersheds were once like giant sponges, absorbing rain in the fall and winter, releasing it slow and steady in the spring and summer. As our watersheds are paved over, rainfall has nowhere to go except downhill. Fast. Winter floods are becoming more intense, causing increased damage to property and salmon habitat, while summer stream flows are becoming too low for salmon returning to spawn.

We know there are ways to grow other than those that hurt salmon. The Nisqually Tribe, for example, is working closely with the Eatonville community to reverse its stormwater impacts on two important salmon tributaries. The aim of the joint project is to completely disconnect the city’s stormwater system from the two rivers.

The Tulalip Tribes recently retrofitted a school’s stormwater drains on their reservation with low impact design technology. Engineered wetlands help absorb stormwater runoff from the school, while vegetation helps filter pollutants before they can reach Tulalip Bay.

Low-impact development reduces impacts to salmon and our environment, and in most cases, it actually costs developers less to do the right thing.

The state Department of Ecology is working toward a stormwater permitting process to help cities and developers stop polluted runoff from getting into our waters. One way is by requiring low impact development practices that help preserve the natural conditions that we still have left in our watersheds.

These stormwater permits have already been delayed by the political process. They need to move forward, and soon. Puget Sound chinook have been on the Endangered Species Act list for more than a decade, yet there have been no substantial improvements to the environmental laws that got us into the problem to begin with. That needs to change, and the stormwater permitting process is a step in the right direction.

Billy Frank, Jr. is chairman of the Northwest Indian Fisheries Commission.