Dynamic Evaluation of Frank Lake Management Alternatives

Abstract

A water balance analysis is presented for the Frank Lake wetland complex, located in southern Alberta, Canada. Frank Lake is operated by Ducks Unlimited to provide waterfowl and shorebird habitat, but also receives effluent from municipal and industrial sources. The complex represents an important staging area for spring and fall migration, and supports a seasonal resident population in the order of 10,000 ducks. The availability and reliability of the water supply, and potential improvement to the management of the wetland complex were evaluated for a number of management scenarios. The methodology for this assessment incorporated a dynamic modelling tool to conduct water balance simulations for a range of possible hydraulic configurations and operating policies for Frank Lake. The selected tool, STELLA by High Performance Systems Inc., facilitated efficient model calibration and testing of different management options. Experimental learning exercises were then used to evaluate alternative operating policies and diversion options based on several objectives. These objectives include flood control to prevent discharges to the Little Bow River, retention policies for efficient treatment of effluent prior to discharge from Frank Lake, and optimal control of water levels for shorebird habitat. The complexity of the water management objectives presented interesting challenges for selecting appropriate management measures. The dynamic object-oriented water balance model proved to be a powerful analytical aid for improving the understanding of hydraulic characteristics of the wetland complex, for identifying practical operating rules for hydraulic control structures, and for altering the water management system of basin control structures and diversion channels. Additional studies for evaluating water quality are not reported here.