A new model was developed to predict the temperature and volume of water runoff from paved surfaces like parking lots. This model can help assess how urban development affects the temperature of streams where fish live. By simulating rainfall events on a parking lot, the model predicted runoff temperatures and volumes very accurately. The researchers found that the model closely matched the results of a more complex model, with only small differences in temperature and volume predictions. This new tool will be useful for understanding how changes in land use can impact the environment, especially in areas with coldwater streams.