Development of a Guide to Lake and Reservoir Zone Determination

Reservoirs are generally created by damming rivers. The upper reaches of any reservoir is generally narrow and winding like the parent river. This is the riverine zone of the reservoir. The reservoir is deepest and widest near the dam. Here, lake-like conditions exist and the water is quiescent. This is the lacustrine zone. The transitional zone separates the lacustrine and riverine zone. It has intermediate characteristics.

There are many characteristics, both physical and chemical, that differentiate between these three zones. Based on the differences in characteristics between the three zones, a method has been developed to successfully divide any reservoir into three zones. The method developed was applied to Lake Manassas and the Occoquan Reservoir located in the Occoquan watershed in Virginia. Both are man-made impoundments.

Analysis of data, based on the method developed, was successfully in dividing both reservoirs into the three zones. This method may therefore be successfully applied to obtain zonation in reservoirs.