To set water use reduction targets, you must first understand your starting point. Collect utility water and sewer consumption data for main meters as well as any submeters for which data are available (e.g., cooling tower makeup, irrigation). Enter data into the Watermark! benchmarking tool to quantify the baseline for your facility and compare it against that of similar facilities.
The benchmarking tool provides a starting point. The analysis of submetered data will give you additional insight into where and how water is being used in a facility. A more detailed water audit can provide even more granular data and pinpoint problem areas. Select the level of data collection that is appropriate to your available resources and desired level of detail.
Target lowest-performing facilities first, and create a list of potential water reduction strategies that could be applied to them. Begin with basic strategies and progress toward advanced strategies (see below). Basic strategies are the lowest cost, lowest-risk opportunities for reduction. Basic and intermediate strategies are both focused on reducing water consumption, but intermediate strategies typically require a greater investment. Advanced strategies address alternative water sources for reducing a facility’s reliance on utility-supplied water. It is recommended that facilities reduce consumption before considering alternative sources.
Basic: Repair or optimize existing systems (fix what you have). The Green Light Projects provide suggestions for reducing water consumption by optimizing systems and equipment that are already in place. Strategies include checking for and fixing leaks, insulating hot water pipes, and optimizing cooling tower operation.
Intermediate: Optimize operations. Assess and recommission systems and controls to minimize water use. Upgrade fixtures, equipment, and systems to more efficient models. Eliminate or significantly reduce the use of potable water for processes that do not require potable water.
Advanced: Collect rainwater and treat gray water and/or blackwater and use it in place of potable water for non-potable applications. (The use of collected rainwater or treated wastewater for potable use is a strategy for research and consideration, but is not considered a near-term solution.)
Refer to the Performance Improvement Measures database to explore the range of potential water-saving projects in more detail.
When setting targets, consider the facility’s baseline in relation to that of similar facilities, along with the age of the building and systems. For example, there is more potential to save water in a building that has high water consumption and old plumbing fixtures than in a newer facility that already has efficient fixtures. Facility staff can set overall reduction goals based on a high-level assessment of a building and its systems. To set more refined targets, a detailed water audit is recommended, which could be performed either by knowledgeable facility engineering staff or by a consultant.
The reasonable range of reduction targets corresponding with each strategy level is as follows:
- Basic: 10-30% reduction of total water consumption and related utility costs
- Intermediate: Up to 40% reduction of total water consumption and related utility costs, when combined with basic strategies
- Advanced: Up to 60 % reduction of total water consumption and related utility costs, when combined with basic and intermediate strategies