Abstracts

Analysis of Water Storage Potential within a Context of Integrated Watershed Management and Climate Change Adaptation

Jean-François Cyr¹, Richard Turcotte, Stéphane Pugin, and Louis-Guillaume Fortin
¹Environnement Québec
francois.cyr@menv.gouv.qc.ca

The Centre d'expertise hydrique du Québec (CEHQ) is an agency of Quebec's Ministère de l'Environnement. It has a dual mandate to manage the water regime of watercourses in Quebec and to manage the provincial government's dams. In addition, in the course of the implementation of Quebec's policy on water, the CEHQ is providing support to the Organismes de bassin versant (watershed agencies), which were created under the policy for integrated watershed management. These different mandates relate to all water management activities with multiple (and sometimes opposing) objectives, such as flood control, low-flow support, water supply, support for recreational and tourist activities and hydroelectric generation. As a result, the CEHQ is directly affected by anticipated climate changes and their impacts on watershed hydrology. In fact, should the water regime undergo significant changes in the coming decades, the current equilibrium between different objectives, which are articulated in water management plans and which represents a compromise for different types of users, may be upset.

Consequently, as one the first milestones in the process of defining a climate change adaptation strategy for the management of public dams, the CEHQ began a study on two pilot subwatersheds in January 2005, in order to develop a methodology for evaluating the adaptation potential of integrated watershed management. The first watershed selected is in Haut-Saint-François, in southern central Quebec, in which we find the reservoirs of Saint-François (Jules-Allard dam) and Aylmer (Aylmer dam). The second subwatershed is located in the Châteauguay River watershed, on the southwest boarder of Quebec. The latter currently has no water storage mechanism, despite an increasingly salient need for water supply management and low-flow periods in order to satisfy the significant needs of truck farming. From a technical point of view, the project is based on preliminary climate change scenarios and on a deterministic hydrological model with daily time steps to evaluate the impact on hydrology of these two basins. The model, which will reproduce the behaviour of the watershed and its management in current climate conditions, will provide the basis for comparison and analysis in the evaluation of climate change conditions. The project is also based on an integrated watershed vision and on the participation, to varying degrees, of users in the discussion of possible adapted management scenarios. In this way, climate change impacts and their attenuations, with possible adjustments to the management plan, can be compared through their effects on the occurrences.

2005-04-05