Congress Resources: Papers, posters and presentations

< Return to abstract list

Water Soft Paths: A Demand-based Approach For Long-term Planning

Congress: 2015
Author(s): David Brooks (Ottawa, Canada)

Keyword(s): Sub-theme 9: Water allocation among competing uses and users,

The key to a fresh approach for water management -- one that seeks sustainable water security -- lies in shifting policy from expanding supply to moderating demand. A full shift requires a two step process: first, from supply management to demand management; then, from demand management to what is called a soft path. Water demand management seeks primarily economic efficiency, better ways to achieve the same service with less water. Water soft paths (WSP) accept the importance of greater water efficiency, but seek a triple bottom line: economic efficiency, social equity and ecological sustainability. WSP accomplishes this by making two significant changes to the current methodology: 1) it changes the conception of "water" from an end to a means; and 2) it replaces projections forward with scenarios work backwards from a desired future to find a range of policies that can guide our efforts to reach that goal. In practice, demand management asks the question "How": How can we get more from each drop of water? Cost-effective savings typically reach 30 to 40 per cent of current use. Water soft paths ask the question "Why": Why should we use water for this task at all? Using WSP, potential savings reach 80 to 90 percent of current use.

Research on water soft paths in Canada, the first such studies anywhere in the world, explore what water soft path policies might achieve at three scales: For example, the Annapolis Valley in Nova Scotia has a maritime climate but only 10 % of the rain falls in the summer when nearly half of withdrawals occur -- mainly for golf courses and agriculture. Sustainable limits are already being exceeded nearly every third year. Adding soft path methods including, for example, using wastewater on golf courses, rooftop rainwater harvesting for homes, and high-efficiency irrigation on farms could reduce summer use to half its current level and almost assure sustainable supplies.

Urban water use, which is dominated by residential, commercial and institutional sectors, was modeled in a generic community that expects to grow in population by 50% over the next 40 years but that seeks to keep water use to current levels. Conventional projections show water use growing by 50% but adding such WSP measures as extensive xeriscaping, dry sanitation, and policies directed at behaviour and lifestyle choices are sufficient to keep future water use well below today's level.

. There is no optimum or "best" approach from water soft path analysis. In most cases an analysis can be brought into effect by a range of measures ranging from purely economic to purely administrative. Therefore, water soft path analysis must be accompanied by extensive public participation in order to elicit an acceptable and effective set of policies. York Region, a collection of municipalities north of Toronto, adopted water soft paths as a planning tool along with the goal that water use should be no greater at the end of the study period than at the beginning. The study showed that a water soft path approach significantly reduced the need for new infrastructure and left much more water in situ for maintaining the health of ecosystems. The results of these initial studies of the application of water soft path analysis should be seen as indicative rather than definitive. Nevertheless, they do show that the goal of sustainable water use -- water security -- is within our grasp.

2011 IWRA - International Water Resources Association - - Admin