Voluntary conservation plans improve water quality in Twenty-five Mile Creek in South Carolina

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Twenty-five Mile Creek is a tributary of the Wateree River, and its watershed includes lands in northeastern Richland, western Kershaw, and southern Fairfield Counties in central South Carolina.  Much of this area is rural, but the watershed does include urban and suburban areas in and near the growing towns of Blythewood and Elgin.

In 1998, Twenty-five Mile Creek was identified on the South Carolina 303(d) list for violations of the fecal coliform bacteria standard at a water quality monitoring station at the bottom of the watershed.  In 2004, an approved Total Maximum Daily Load (TMDL) was written for fecal coliform.  According to this TMDL, a fecal coliform bacteria pollutant load reduction of 71% is required to meet clean water quality standards!  In 2000, the stream was also placed on the 303(d) list for macroinvertebrate community impairments (meaning the biological community one expects to find in a healthy aquatic ecosystem is reduced in quantity or absent); to date, a TMDL has not been developed for this macroinvertebrate impairment, but local landowners and conservationists are nonetheless eager to improve the overall health of the watershed and improve macroinvertebrate community composition in the creek.

Because the watershed includes diverse land uses, factors affecting water quality in Twenty-five Mile Creek are complex.  Notable impacts include numerous livestock operations and horse farms, impacts from suburban development, urban runoff, failing septic tanks, and wildlife.  In 2013, watershed based plans were developed to address both bacteria and macroinvertebrate community impairments, and based on these plans, watershed partners prioritized the reduction of water quality impacts from (1) agricultural sources and (2) failing septic systems.

Solution:
In 2014, a team of watershed partners (including Richland, Kershaw, and Fairfield Counties; Richland and Kershaw Soil and Water Conservation Districts; and a consulting team from Amec Foster Wheeler) coordinated funding from a Section 319 grant and from the Richland and Kershaw County stormwater programs to provide financial assistance to farmers and livestock owners in the watershed.  This financial assistance covered 70% of the cost of the development of conservation plans and the installation of Best Management Practices (BMPs) and was designed to work in tandem with the USDA-NRCS Environmental Quality Incentives Program.

With assistance from USDA-NRCS, resource concerns on six cattle and horse farms were identified, and a Richland SWCD conservationist worked with landowners to develop and implement eight conservation plans.  At the end of the three-year project later this year, landowners will have installed some 5.8 miles of fencing, 5.9 miles of water lines, and 28 alternate water sources to keep livestock out of streams and wetlands and improve grazing management.  The Richland Soil and Water Conservation District has also focused educational efforts on livestock owners in the watershed, and several pasture management workshops have promoted information about rotational grazing, soil health and fertility, and manure management—all of which can have a positive effect on water quality.

In 2017, additional funding was made available through a second Section 319 grant and Richland and Kershaw Counties’ contributions to address failing septic systems.  For the next two years, watershed residents can have at least 60% of the cost of qualified septic system repairs covered through cooperative funding.

Benefit:
These efforts have reduced water quality impacts from agricultural and septic sources in the watershed and have raised awareness about local water quality issues and solutions.  Interest in and concern for the watershed are growing; community volunteers have begun monitoring water quality in portions of the watershed through the Adopt-A-Stream program; a local school has installed a rain garden to reduce polluted runoff and educate students and families; and a local education center has installed a rain barrel irrigation demonstration.   Partners are hopeful that these efforts will ultimately lead to the attainment of water quality standards for both bacteria and macroinvertebrate community composition in Twenty-five Mile Creek.