SOLUTIONS TO WATER THREATS IN CANADA
POTENTIAL ADAPTATION MEASURES
Previous study has shown that projected streamflow scenarios can vary widely. Specifically, the choice of reanalysis product to drive (and calibrate) hydrologic models in this region can have considerable impact on the predictions the models make. Stakeholders requiring water supply scenarios, or predictions of streamflow are aware of this issue, which is only exasperated by a lack of observational data to ground-truth models with. To support stakeholders in producing probabilistic forecasts or design inflows, it is necessary to understand the degree of uncertainty propagating from input data into streamflow simulation.
Importance and relevance of adaptation
Long-term planning is essential for stakeholders within the Nelson-Churchill River basin for a variety of reasons, including (not limited to) assessment of: (1) flood risk, (2) net basin supply, (3) climate change impacts and adaptation strategies, (4) risk and water security analyses, (5) improved integrated watershed management practices, (6) improved prediction tools. In the Canadian Prairies, which are considered to be water-limited, improving prediction of future water supply will benefit society (safety, risk mitigation), economics (recreation, fisheries, hydropower, etc.) and environment (best practices, integrated management, water governance).
Pros and cons or cost-benefit analysis of climate adaptation
Small changes in the net basin water supply can cost millions of Canadian dollars in flood damages, lost hydropower revenue, losses in the aquatic fisheries of Lake Manitoba and Winnipeg, or in tourism and navigation of waterways. The costs of not understanding and proactively mitigating climate change risks to water quality and quantity in this basin are palpable and are broadly acknowledge as being far greater than the financial cost of implementing mitigation measures. For example, the basin has a long history of capital investment in flood protection infrastructure, including the Winnipeg Floodway (the largest earthen dam structure in the world) which cost millions but has saved the city of Winnipeg billions of dollars. Benefits include mitigation of social and economic risk, protection of public health and safety, and long term sustainability of the environment and water security in a region that is notoriously water-limited (drought) or excessively flooded.
On a larger scale, water share agreements established under Federal legislation enacted by the Prairie Provinces Water Board, provide requirements for each Prairie Province (and similarly for international basins spanning both Canada and the USA, enacted through the International Joint Commission) that must be met, regardless of hydrologic conditions, for sustainable water supply. There is uncertainty as to the impact that climate change may have on these agreements.