The South Carolina Department of Natural Resource (SCDNR) is legislatively mandated through the South Carolina Water Resources Planning and Coordination Act (§ 49-3-10, et. seq., Code of Laws of South Carolina, 1976) to formulate and establish a comprehensive water resources policy or water plan for the State. The first edition of the South Carolina Water Plan was published in 1998, and was subsequently updated in 2004 to incorporate experiences and knowledge gained from the severe, statewide drought of 1998–2002. The 2004 Water Plan highlighted the need for water planning on a regional level, and in 2014, SCDNR began the process of developing regional water plans that will ultimately support the development of a new State Water Plan. Regional water plans, or River Basin Plans, will developed for the eight major river basins in the State – Broad, Catawba, Edisto, Pee Dee, Salkehatchie, Saluda, Santee, and Savannah. To support the development of the River Basin Plans, hydrologic models have been developed for both the State’s surface water and groundwater resources and will be used along with water demand projections to assess current and future water availability in the State.