TEMPORAL WATER QUALITY VARIABILITY OF LOW ORDER STREAMS IN MID-MISSOURI

One of the challenges of monitoring water quality is the difficulty of adequately characterizing indicator parameters that exhibit significant temporal variability. Although continuous monitoring instrumentation is available for some water quality indicators, continuous monitoring can be expensive, and it is often difficult to find appropriate monitoring locations. Thus, the majority of water quality monitoring occurs through point measurements, which must be used to make management decisions even when the representativeness of the measurement is uncertain. In this research, temporal fluctuations in water quality were monitored in four low-order watersheds (three rural, one urban) in central Missouri to better understand natural fluctuations in water quality. Water quality measurements were taken on a biweekly basis over several months, as well as more intensively over a four-day period to better understand small-scale variations. The parameters acquired were pH, turbidity, electrical conductivity, dissolved oxygen, temperature, nitrate, chloride, and bacteria. These measurements were used to establish background values for these parameters in these watersheds and to observe temporal variability and variability between watersheds. The watersheds were found to have similar water quality values for most parameters, despite the different land use/land cover. The greatest temporal fluctuations were observed in turbidity, nitrate, and bacteria count, while pH and dissolved oxygen were the least variable. A search for correlations between different water quality parameters showed no statistically significant relationships, implying that proxy measurements of water quality using these parameters are unlikely to be successful.