Bacteria TMDLS: Overlaying Water Quality, Hydrology and Corrective Measures on Stream Recreation

Kansas faces numerous issues surrounding the attainment of bacteria criteria and recreation use in Kansas streams. Kansas has employed various approaches, such as load duration curves, use refinement and mandatory wastewater disinfection to appropriately assess and protect stream recreation. An emerging concept uses the flow components of depth and velocity to create profiles of likely primary recreation (swimming, kayaking) on various sized streams. Application of the technique is made on a rural creek and a major reservoir to provide a contrast in the likely hydraulic support for in-stream recreation those streams provide. By overlaying the likelihood of primary recreation on the load duration curve, the context of actual impairment is displayed. A suite of Best Management Practices that would likely reduce bacteria levels at varying flow conditions helps craft a strategy for ensuring the most likely recreation uses are protected on the stream. At the highest flow conditions, physical limitations may offset the need to invest in bacteria reduction during unlikely recreation periods.