INDIANAPOLIS, Ind. (WOWO): Indiana American Water is issuing a warning about the threat that rainwater runoff poses to the state’s waterways.

Indiana has had a very rainy start to spring, the Fort Wayne area included. Now the utility is warning that the heavy rainfalls can cause fertilizer runoff into major waterways that serve as source waters and replenish groundwater supplies across the state.

Indiana American Water President Deborah Dewey says Hoosiers need to be careful what types of fertilizers they’re using to make sure any runoff doesn’t contaminate runoff, specifically warning you to avoid fertilizers that have high levels of nitrogen or phosphorus.