Proceedings of the 1991 Georgia Water Resources Conference, March 19-20, 1991, Athens, Georgia.The reduction of the littoral zone is used as a lake restoration technique that results in nutrient control and water quality
improvement (Yount and Crossman, 1970; Burton et al, 1979;). In contrast, in other cases the littoral zone operates as a protective and pollutant filtering zone and its maintenance is desired (Toth, 1972; Water Resources Management Program Workshop, 1986); in some cases also its protection as a freshwater wetland is desired.
A number of studies and observations indicate that, in both cases, the fluctuations of the lake water level can be used as a management tool for controlling the littoral zone's existence and
extent. ( Jorgensen, 1983; Clausen and Johnson, 1990). The reduction or protection of the littoral zone requires totally
different lake water level management during the year. The water balance of the lake and a number of constraints reflecting the
specific characteristics of the system, the several water uses and the requirements for the protection or reduction of the littoral
zone pose an optimal control problem.
Based on the above concepts, an optimization approach has been developed for management of the water levels in lakes and
reservoirs where the littoral zone plays an important role. Inputs to the model consist of hydrological data for the watershed and
the lake or the reservoir and data on water demand. The model can also be linked with an appropriate watershed model for direct
input of hydrologic data. The objective function and the constraints formulations are based on the management purposes
and on historical data concerning the status of the vegetation zone versus different water elevations. Model outputs are the amount of the water that must be released and the monthly averaged lake elevations during the year. The optimization model uses a dynamic programming algorithm. Detailed descriptions of the approach, sensitivity and testing of the algorithm for hypothetical cases are given in (Tsiros, 1987). The theoretical background of the
approach is based on the results of a comprehensive field monitoring program presented and discussed extensively in
(J0rgensen, 1983). This paper describes the model's formulation, its major assumptions, and its application in a real case problem where impacts to the littoral zone have occurred because of a water development project. The applicability of the approach to regional reservoir planning and management, the limitations and further extensions of the approach are also discussed in the context of applying the proposed approach for management guidelines and recommendations concerning lake management with regard to lakeside vegetation zone control.Sponsored by U.S. Geological Survey, Georgia Department of Natural Resources, the University of Georgia, Georgia State University, and Georgia Institute of Technology.This book was published by the Institute of Natural Resources, The University of Georgia, Athens, Georgia 30602 with partial funding provided by the U.S. Department of the Interior, Geological Survey, through the Georgia Water Research Institute as authorized by the Water Resources Research Act of 1984 (P.L. 98242). The views and statements advanced in this publication are solely those of the authors and do not represent official views or policies of The University of Georgia or the U.S. Geological Survey or the conference sponsors
