Modeling fresh water inflow to an estuary

The Pettaquamscutt Estuary is a unique and valuable environmental feature of coastal Rhode Island. The usefulness of the estuary is now compromised and its viability threatened by land development in the watershed. Water quality investigations reveal a wide range of pollutants entering the estuary system from watershed fresh water input, both as stream runoff and as groundwater outflow. A deterministic computer model has been developed which is capable of simulating existing conditions under a complete set of seasonal scenarios, and able to predict the pollution potential due to alternative land uses. The model is a hybrid model which combines conventional surface runoff solutions with newly created groundwater outflow quantification techniques. Linkage is provided for coupling the freshwater inflow model with estuary mixing and flushing models. Adapted to the readily available IBM microcomputer, the model provides a valuable management tool for use by the three towns situated along the watershed in their evaluation of land use practices and the effectiveness of possible solutions