Estimating Water Availability and Under Ice Volume of Alberta Lakes using Minimal Data (original) (raw)

Alberta's lakes support important environmental, social and economic values. The effect of cumulative allocations over time from lakes within a watershed may impact the health of the aquatic environment, which include fish and wildlife resources. Therefore, water withdrawals from lakes should be regulated in such a way so that ecosystems are preserved while balancing reliable, quality water supplies to sustain communities and economic and recreational opportunities. Accurate estimation of water availability (volume) in a lake requires a complete water balance study, which requires bathymetric information of the lake. However, only a fraction of Alberta lakes have surveyed bathymetry data. In support of provincial policy development and for quantifying the potential impacts of water withdrawal from lakes, approaches to estimating lake volume using limited available data were tested. In this study, we analysed available bathymetry data from 77 lakes and developed three different models to estimate maximum lake volume (a proxy of lake water availability) and 5% under ice volume (a proxy for winter allocation limit of lake water) assuming an ice thickness of 80 cm. These models have been developed in such a way that allows the user to apply the models based on data availability. These models can be used in absence of site specific data (e.g., bathymetry) to estimate volume, and subsequently water availability in lakes.