A MODELING CASE STUDY: THREE DIMENSIONAL WATER QUALITY MODEL FOR THE CHARLESTON HARBOR SYSTEM

A three-dimensional (3-D) water quality model for the Charleston Harbor System (CHS), South Carolina, is being developed for the Berkeley-Charleston-Dorchester Council of Governments (BCD-COG) to assist in developing the dissolved oxygen Total Maximum Daily Load (TMDL). Model development of the CHS has occurred through two previous completed efforts since 1990. In the most recent effort it was recommended, based on work in other estuaries, that a 3-D model is necessary to represent the complexities of the dynamics of dissolved oxygen and that it is more appropriate, than the previous 1-D and 2-D efforts, for the CHS. A series of linked models were developed to represent watershed flows, instream hydrodynamics, and instream water quality in the system.The ultimate goal of the 3-D water quality model is to develop a management tool to determine the TMDL and wasteload allocation strategies for the Charleston Harbor System. The water quality model will engage all stakeholders including the industries, local governments, and regulators in establishing the assimilative capacity of oxygen-consuming pollutants.