City residents can benefit from the advice of a soil scientist during the drought. Bill Liebhardt, director of the UC Davis-based UC Sustainable Agriculture Research and Education Program, knows his dirt. And he says knowing the kind of soil you have and matching your sprinkler system to it is one of the best ways to save water. "The biggest problem with city residents is that they overwater," Liebhardt says. This is a result of not taking into account their sprinkler system's ability to deliver water and their soil's ability to absorb it. If they're not matched, the soil can't absorb water as fast as the sprinkler delivers it and the water runs down the street. "It's like trying to drink a 5-gallon milkshake in two minutes. You can't do it," Liebhardt says. "Even if you don't have drought-tolerant landscaping, you can save water by watering carefully -- in the morning, evening or night." Water loss can also be reduced by mulching vegetables and ornamentals. Mulch can be grass clippings, compost from the city dump and chipped prunings.