Saltwater intrusion modeling of the Savannah harbor expansion project

Abstract

The Army Corp of Engineers (ACOE) hired CDM to develop a 3-dimensional ground water model of the Savannah harbor area, with the intent to use the model to simulate saltwater intrusion from the Savannah River harbor area, both under present conditions and under the proposed conditions after dredging. The model includes modules to simulate flow, transport (using particle tracking), and density driven flow using a coupled flow and transport code suitable for simulation of saltwater intrusion and leakage. Model simulations were designed to assess the rate and magnitude of downward leakage of saltwater along the river caused by the steep decline in heads in the Upper Floridan Aquifer in the Savannah area due to pumping. Comparative runs were made under present day conditions, and after proposed dredging of the harbor, which would result in a decrease in the thickness of underlying Miocene Confining Unit deposits.