This planning step requires that planners revise the demand and supply-capacity forecasts made during Planning Steps 2 and 3 by incorporating anticipated conservation savings. This may enable adjustments to supply plans and integrates both supply management and demand management activities, resulting in an optimized, cost-effective water system.
Planners should begin this step by modifying the demand forecast(s). They can then examine the effects of conservation on specific supply-facility projects, water purchases, and other requirements related to water demand such as wastewater facilities.
Planners should be cautious to avoid counting demand-side or supply-side resources more than once in the analysis. Anticipated savings from conservation should be based on realistic estimates of savings associated with the planned measures and programs. Similarly, supply projects that involve multiple facilities should be considered in terms of the total water supply capacity that is made available through those combined facilities. Timing is another issue. The plan should address how different supply-side and demand-side projects involve different life spans and implementation schedules. One twenty-year supply-side project, for example, might be offset by a series of conservation measures that begin and end at different times.
Conservation plans often use a graph to display anticipated annual demand and supply capacity requirements with and without the implementation of conservation measures. The figure provided below is an example of this type of graph for a twenty-year planning horizon. It summarizes much of the work done to this point in the conservation planning process.
Modify water demand and supply-capacity forecasts to reflect the anticipated effects of conservation. Indicate whether and how water savings from conservation will allow the system to eliminate, downsize, or postpone new facilities or water purchases.