As climate warms, cities look to adjust

SPOKANE — Unlike her neighbors', Rachael Paschal Osborn's yard isn't an expanse of green grass meticulously fertilized and watered on schedule by timed sprinklers.

Paschal Osborn, a public-interest lawyer who teaches water law at Gonzaga University's Law School, doesn't like to waste a drop. So the grass in her west Spokane yard is brown during the summer, while drought-resistant native plants and her vegetable garden thrive on drip irrigation.

Climate experts say the rest of Washington may have to follow Paschal Osborn's example in the future as global warming changes the way residents use water on their yards and in their homes.

The gradual warming of the earth's surface will have both benefits and drawbacks for municipal water systems, they say.

Kurt Ungur, a hydrogeologist with the state Department of Ecology, said a warmer climate likely will produce about the same amounts of precipitation — possibly a bit more — but its timing will change from historic patterns.

In winter, more precipitation will fall as rain, rather than snow, which serves as the mountain "bank" for much of the state's water supplies. In spring, warmer temperatures will bring earlier runoff, leading to potential conflicts over scarce water in late summer, he said.

Paschal Osborn, co-founder with husband John Osborn of the nonprofit Columbia Institute for Water Policy, said most of the state's cities are unprepared for the consequences of global warming.

"The potential for change is dramatic. It could change the natural ecology of forests. It is also going to change the human landscape," Paschal Osborn said. "It will change what we can grow for crops and what we can grow in our yards."

Paschal Osborn, Ungur and others point to Seattle, which has taken the lead in promoting water conservation and planning for the effects of climate change.

Heather Cooley of the Pacific Institute for Studies in Development, Environment, and Security in Oakland, Calif., said communities could reduce their annual water consumption by 30 percent through use of low-flow devices, efficient landscaping and more efficient use of water by commercial and industrial customers.

Paul Fleming, manager of climate-change initiatives for Seattle's water utility, said the key will be mitigating effects of greenhouse-gas emissions, then adapting to the changes that warming will bring.

"The impacts don't manifest themselves for quite a while. I think we have some time to make investments to strengthen the resiliency of our system," Fleming said.