Today, the engineer is faced with the task of predicting and evaluating the extent of the Nonpoint Sources that pollute our waterways. A mathematical model may be an extremely useful tool in helping the engineer solve problems in the area of water resources. During the course of this investigation, a literature survey related to the Econlockhatchee River Basin and to the "STORM" mathematical modeling technique for runoff evaluation has been conducted. The latter part of this report deals with an application of the "STORM" mathematical model for predicting quantity and quality of surface runoff for the Econlockhatchee River Basin located in central Florida.