The National Weather Service is using flood prediction models to help prevent pollution year-round.
The River Forecast Center in Chanhassen, Minn., uses complex computer models to predict flooding based on many factors, including precipitation and soil moisture.
The models that predict flooding can also tell when rain will cause runoff from farm fields, said National Weather Service hydrologist Steve Buan, who added that the information can help farmers avoid polluting streams by properly timing the application of manure on fields.
"With three days' notice, the rainfall forecasts are reasonably accurate," Buan said. "But sometimes what sounds like an innocuous amount of rain, if you don't incorporate what the soil capacity has for taking that rain in, there may be a critical threshold that will be overcome, and you'll see runoff and it will be unexpected."
Buan added: "It's beneficial for the environment but also beneficial for agricultural producers in that it saves them money -- that they wouldn't apply at the wrong time and use the fuel, and it also saves the nutrient value of the manure. So it's kind of a win-win situation."
The model might also be useful for farmers applying commercial fertilizers, Buan said.
Wisconsin is using the new runoff prediction model statewide. Buan said the same service might be available in Minnesota by next year.
Phosphorus runoff from farm fields is a major source of water pollution.