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A minimum in the dissolved oxygen distribution of numerous lakes and reservoirs has been observed to develop in the metalimnion during the stratified period. This minimum is usually explained by the accumulation of organic matter from the overlying layer of water. The introduction of organic matter from the interflow of storm water is also a likely contributor to the accelerated oxygen depletion within the metalimnion. Data are presented that demonstrate that even during low flow periods, water containing reduced species in the deeper upstream section of DeGray Reservoir, Arkansas, is being incorporated into a density current and transported advectively through the metalimnetic region. This mechanism may contribute significantly to the development of metalimnetic dissolved oxygen minima in reservoirs with similar stratification and flow characteristics to DeGray Reservoir.

Knowledge of coliform transport and disappearance may provide information for project design and operation that minimizes potential water quality problems such as the violation of body contact recreation standards. Storm events were sampled in the Caddo River above DeGray Reservoir, Arkansas, and then tracked through the reservoir using the increased turbidity associated with the storm flows. Fecal coliforms were sampled both in the river and throughout the water column in the reservoir. In general, increased fecal coliform concentrations were closely associated with the increased turbidity resulting from the storm flows. This association existed for all three types of turbidity plume movement ‐ overflow, interflow, and underflow. As the turbidity plume moved down the reservoir, fecal coliform concentrations decreased due to die‐off, settling, and dilution. With several assumptions, it is possible to use this information to assist in locating recreational sites in a reservoir or to anticipate possible body contact standard violations at existing recreation sites.