Will lake draw down help water quality?
Updated: Sep 28, 2020
Back in September of 2013, SCE&G announced plans to lower the lake to enhance water quality. The lake was gradually dropped to the 350 foot level by December lst. On January 1st, the refill began back to the normal high pool level of 358 feet. The company explained, “In years past, periodic draw downs to similar levels were conducted that allowed rain to scour shallow coves which greatly benefits water quality. The last draw-down such as this was conducted in 2006.” As part of the relicensing process, SCE&G contracted Jim Ruane, a consultant with Reservoir Environmental Management Inc. to evaluate how project operations impact water quality in the lake and the lower Saluda River. Ruane told members of the Water Quality Technical Working Committee, that “drawing Lake Murray down to the 350’ elevation would have significant benefits to water quality in the upper lake region.” A study, using water quality model developed from Ruane’s previous experiences at other lakes, indicated that the Little Saluda embayment has the potential for nutrient build up. Lowering the lake significantly during the winter increases scouring of organic and inorganic matters, and increases water exchange from the embayment and the main water body. This decreases internal nutrient cycling and lessens the possibility that the decay process will deplete dissolved oxygen (DO) levels that could result in fish kills. Low DO water eventually migrates to the dam area further complicating conditions necessary for striped bass survival during the hot summer months.
Lake groups questioned whether Ruane’s model would work on Lake Murray, noting the model was developed from a study conducted on a neighboring lake. The recent temporary drawdown after 8 years should provide an opportunity to test Ruane’s theory. An evaluation of data collected before and after should show whether or not higher lake levels compromised water quality. Will the recent draw down , improve DO as theorized by the model. Stay tuned for the results. Steve Bell is President of Lake Murray Watch.com, a signatory of SCE&G’s license agreement, and owns Lake Murray Images. Email email@example.com.