Water availability assessment of S.C. river basins continues to flow with vigor
DUNCAN – When you’re dealing with something as invaluable as water, it’s good to hope for the best but plan for the worst.
An ongoing collaborative effort involving Clemson University, two state agencies and one private company aims to do just that by conducting a surface water availability assessment that will eventually become a key component of a long-term, multifaceted state water plan for the rivers of South Carolina.
The S.C. Department of Natural Resources, in conjunction with the S.C. Department of Health and Environmental Control, initiated the program to develop surface-water models for each of the state’s eight major river basins: Saluda, Edisto, Broad, Pee Dee, Catawba, Santee, Savannah and Salkehatchie. In 2014, the state hired CDM Smith, a private consulting and engineering firm, to develop hydrologic models of the state’s river systems. Clemson University was brought on board to facilitate a statewide stakeholder engagement process aimed at involving the public in the development of the models, as well as building awareness of the effort.
Two stakeholder meetings have been planned for each of the eight basins. Stakeholders are defined as anyone who lives in or near the basins and uses water, including individuals, businesses, institutions and government entities. The initial stakeholder meeting, which focused on the Saluda Basin, was held last year in Greenville. The 10th and latest meeting, which targeted the Broad Basin, was held May 18 at Spartanburg Community College’s Tyger River Campus. Six meetings remain: one each for Catawba and Santee and two each for Savannah and Salkehatchie. These should be concluded by the end of this year.
“We have been asking stakeholders, ‘How important do you feel the surface water availability assessment is for water resources management?’and most folks have said that it is very important.” said Jeffery Allen, director of the S.C. Water Resources Center at Clemson University. “Our team obviously agrees with that. So we will keep moving forward with the goal of putting South Carolina in a good position to manage its water resources in the future.”
Surface water quantity models are computer programs that simulate water systems using mathematical equations to approximate the behavior of water in those systems. CDM Smith’s Simplified Water Allocation Model will be capable of accounting for all the inflows and outflows in the eight basins.
“A simplified water allocation model is a water accounting tool. It’s kind of like your checkbook only it’s accounting for water instead of money, and this is all based on U.S. Geological Survey flow records from 1983-2013,” said John Boyer, project manager for CDM Smith. “We’re doing our best to match what went on over that historical record to build baseline models that we can then use to conduct ‘what-if’ scenarios. Ultimately, this will support the overall state water plan.”
CDM Smith engineers Kirk Westphal and Nina Caraway presented specific examples of how the CDM models simulate streamflow conditions by accounting for inflows and outflows, water withdrawals and discharges, and even climactic patterns. Both emphasized the importance of stakeholder involvement in the ever-evolving computational operation.
“This is an opportunity for you to participate and provide some feedback to us. Calibrating is an ongoing process, and as you see things that you question or have questions about, please pass them along and we’ll try to address them,” Westphal said to the audience. “When we start to do predictive runs as part of the statewide planning process, we’ll have confidence that the hydrology in the operations is correctly represented.”
Rob Devlin, a manager in DHEC’s Bureau of Water, stressed the importance of developing a wide-ranging state water plan that is backed by scientifically accurate estimations of surface water quantity and location.
“For a long time, everybody thought that the South was rich in water, which we were, unlike the arid Southwest,” Devlin said. “But our population increased. And industry and agriculture increased. And more people were using more water. And then the drought of 2002 came, which got the state Legislature thinking that we really – for the long-term viability of our water resources – need to look at some regulatory capabilities and some planning.”
Hydrologist Joe Gellici, who represented the Department of Natural Resources, said he hoped the models would help to resolve water disputes and also support the development of drought-management plans.
“We’re particularly interested in those low-flow periods when water’s scarce and we’ll be using the models to predict when and where water shortages will occur,” Gellici said. “We’ll be doing water-demand forecasting, plugging those water demands into the model and finding out if there will be deficits in the future, when those deficits will occur, where they will occur and for how long. And if there are deficits, we can use these models to test alternative water-management strategies.”