Various pollutants are produced too much in our environment, and they are accumulated on road surfaces, roofs, and open areas. Since most accumulated loads on road surfaces are gathered into street inlets, we never ignor the influences of pollution loads in street inlets on runoff water quality.
So, we derive the model for runoff loads from street inlets which are one of nonpoint pollution sources, in order to make clear the influence on runoff loads on rainy day and the runoff characteristics, and we simulate runoff loads by our model on the basis of the results of runoff experiments.