Water Quality Assessment in a Restored Section of the Cane Run Watershed, Lexington KY.

Parameters influencing water quality in riparian environments include nutrient uptake by vegetation, flow and depth of stream, temperature, wildlife or nearby agricultural inputs, and temporal variability.  This assessment of water quality was conducted concurrently with a riparian buffer restoration project on a channelized tributary of the Cane Run Watershed in Lexington, Kentucky.  We evaluated the stream distance required to see differences in water quality parameters such as nutrient content, biological oxygen demand (BOD), total heterotrophs, and coliforms. Three stream distances were assessed for water quality parameters: the distance across the stream, and 40 m and 644 m reaches along the stream. The 640 m reach extended past the boundaries of the riparian buffer zone; the 40 m reach was nested within the riparian buffer zone. From August to December 2011 NO₃^- -N concentration in the 644 m reach ranged from 0.2-1.8 mg L^-1 up to 3.2-5.7 mg L^-1 depending on sampling date.  Total heterotrophs on nutrient agar ranged from 5,850-72,600 CFU/100 mL while typical coliforms on M-Endo agar ranged from 0-3,550 CFU/100 mL. Within the 40 m reach the range of heterotrophic bacteria was 48,400-73,500 CFU/100 mL while typical coliforms ranged from 100-3,000 CFU/100 mL.  Fecal coliforms were never greater than 80 CFU/100 mL while atypical coliforms usually far exceeded typical coliform counts. Electrical conductivity (EC), pH, and biochemical oxygen demand (BOD) were not appreciably changed by passage through the riparian corridor. Data collected at four different times suggested that the longest distance, 644 m, was needed to see differences in BOD and nutrient content. A shorter distance of 40 m was enough to see differences in bacteria.