Okanagan Climate Change: Fish/Water Management Impacts & Adaptation Strategies
Fisheries and Oceans Canada
During the winter of 2004, Hyatt and Alexander (2005) completed a retrospective analysis to examine the potential impact of historic water management decisions on annual production variations of Okanagan sockeye and kokanee salmon. The analysis was aided by the use of an advanced decision support application known as the Okanagan Fish and Water Management Tool (FWMT) system.
The FWMT system consists of a coupled set of 5 biophysical models of key relationships among climate, water, fish and property (flooding) to predict the consequences of water release decisions at Okanagan Lake Dam, given variation in annual net inflows and patterns of seasonal inflow. The purpose of this project was to extend the use of the FWMT system to predictions of potential impacts of 2050 climate on fish-and-water management outcomes in the central and southern Okanagan valley. The project involved converting downscaled future water budget and water temperature datasets (2040 – 2069) for Okanagan Lake and River. Water budget and temperature datasets are based on the HadCM3 (A2) global climate model developed at the Hadley Centre in the United Kingdom, with downscaled surface hydrology provided by the UBC Watershed Model and future demand assumptions based on studies of other members of the Cohen et al. research team (Cohen et al. 2004). Having converted these datasets to FWMT format, the project then includes a prospective analysis of water trade-off decision making, based on work of “apprentice” fish-water managers, to simulate future decision-making under climate change. Results of this analysis will be used to quantify future impacts on sockeye salmon production outcomes, in relation to the pervading flood and drought management rules that are also built into the FWMT system.