U.S. Department of Energy - Energy Efficiency and Renewable Energy
Federal Energy Management Program
Best Management Practice: Water Management Planning
A successful water management program starts with developing a comprehensive water management plan. This plan should be included within existing facility operating plans.
Water management plans should provide clear information about how a facility uses water from the time it is piped in to its ultimate disposal. Knowing how water is used and what it costs enables Federal agencies to make appropriate water management decisions.
Water management planning is covered across:
Federal facility water management plans should include the following:
Water Use Policy Statement and Goals
Senior management should indicate support for water efficiency in a material way. This can be done in two ways:
By providing a written policy statement that ties water efficiency into the long term operating objective of the facility or organization.
By making the necessary staff and financial resources available to track water use, maintain equipment, and implement cost-effective water use reduction projects.
The facility should translate its water efficiency policy into specific water use reduction targets in coordination with its headquarters organization. Per Executive Order (E.O.) 13514, each Federal agency, beginning in fiscal year 2008, is directed to reduce water consumption intensity, relative to a fiscal year 2007 baseline, 2% annually through the end of fiscal year 2020 or 26% by the end of fiscal year 2020 through life-cycle cost-effective measures. In addition, Federal agencies are required to reduce industrial, landscaping, and agricultural water use by 2% annually through fiscal year 2020 or 20% by the end of fiscal year 2020. The numeric targets can only be achieved at the agency level if specific reductions are achieved at the facility level.
A system like an environmental management system (EMS) utilized by Federal agencies can serve as an excellent existing structure to establish policies and goals related to water use and to monitor progress once water use is identified as a significant environmental aspect of the facility. See BMP #2 for additional information.
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An essential element for calculating cost savings and implementing projects associated with water efficiency opportunities is to identify the marginal cost of water and sewer service on a unit basis, verify that you are on the appropriate rate structure, and identify any services your utility might provide to help manage water more efficiently. Appropriate utility information should include the following for both purchased potable and non-potable water:
- Contact information for all water and wastewater utilities.
- Current rate schedules and alternative schedules appropriate for your usage or facility type to ensure you are paying the best rate.
- Copies of water/sewer bills for the past two years. This helps identify inaccuracies and ensure the appropriate rate structure is applied.
- Information on financial or technical assistance available from the utilities to help with facility water planning and implementing water efficiency programs. Energy utilities often offer assistance on water efficiency.
- Contact information for the Federal agency or office that pays the water/sewer bills.
- Production information if the facility produces its water and/or treats its own wastewater.
When collecting the above information, consider that you need to separately gather data on potable water use and industrial, landscaping, and agricultural water use (primarily non-potable water) associated with E.O. 13514 reduction targets.
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Water Use Information
An important step in creating a water management plan is establishing a water balance for the facility. A water balance is a method to compare the total water coming into the site to water that is used by equipment and applications in the site. A water balance includes identifying and quantifying, to the extent possible, current water use. Most Federal facilities have metered data for total water use and may have limited-to-no sub-metering data on component uses. However, a walk though audit of the facility coupled with a basic understanding of how water is being used and some engineering judgment enables the assessor to create a relatively complete account of how water is being used and the approximate quantity used for each purpose along with losses in the system. This basic level of understanding is crucial. Once you have a good understanding of water use and how much you are using for each purpose, you will have a solid basis to identify potential water saving opportunities.
The following six steps outline the process for assessing water use trends at your facility:
Plot water use data from the utility water bills for the prior two years. Is water use increasing, deceasing, or steady? Do you know why? Is there a seasonal pattern to water use? This is often the case when irrigation water is used or cooling water demand increases in the summer months.
Create an inventory of all water using activities. Other BMPs provide a good checklist as a starting place. You may need to tap the expertise of others at the facility with direct knowledge of building mechanical systems and process equipment to generate a complete inventory.
This step should include a walk-through audit of the facility to identify all significant water using processes and associated operating characteristics. As part of the walk-through audit for each piece of equipment, note the operating schedule, flow rate, model number, and condition. During the walk-through, pay particular attention to drain lines plumbed to floor drains in building mechanical spaces and utility chases. Trace these back to the originating equipment to make sure you include them in the inventory.
For all water uses on the inventory, obtain any sub-metering data that may be available. Any such data helps quantify that particular use. You can also make a quick, rough estimate of equipment flow rate (e.g., faucets, showerheads, and once-though cooling) using a bucket and stopwatch technique to measure the flow rate.
Evaluate any seasonal patterns and compare this to your inventory of uses. Are any uses seasonal in nature, such as cooling tower use or irrigation? The seasonal pattern of water use (peak use) can help quantify these uses.
Use supplemental data to create engineering estimates of use. For example, estimate water use from plumbing products (toilets, urinals, faucets, and showerheads) based on the number of occupants and daily use per occupant; cooling tower use based on cooling capacity and load factor (see BMP #10); irrigation water use based on irrigated area and inches of water applied (discuss with your irrigation contractor); and operating equipment water use based on water use per cycle and frequency of cycles.
After this process, evaluate the results. Does the inventory and associated water use account for most of the metered water use? If not, have you missed a major water consuming piece of equipment or distribution system leaks (see BMP #3)? After stepping through this process, you will know what your big water using activities are, which will help prioritize water saving opportunities.
If you do not have metered total water use information for your facility, examine the component water uses in your estimating basis and the relative contribution of each component. This helps prioritize saving opportunities. Note that your local water utility or agency headquarters may have water efficiency assessment staff that can help with assessment activities.
The above steps should be performed for both the potable and non-potable water consumption at your site if applicable.
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Metering or Measurement Plan
Once you have conducted the assessment, evaluate the biggest water using activities and the quality of data available for that use. Consider installing sub-meters on water intensive processes, such as cooling towers and irrigation systems. Due to mandated water reduction of industrial, landscaping, and agricultural water uses, consider sub-metering these applications, which will help to manage these processes better and assist in annual reporting requirements. You can more carefully control processes when you have accurate, quantitative data.
Your plan should assign responsibility to track water use on an ongoing basis. Continue to plot total water use as new water bills become available. Also plot any available sub-metered data. Evaluate trends and investigate and resolve any unexpected deviations in water use. Track water use reductions and publicize your success.
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Emergency Response Information
Develop water emergency and/or drought contingency plans that describe how your facility will meet minimum water needs in an emergency or reduce water consumption in a drought or other water shortage. This should be done in conjunction with local water suppliers.
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Inform staff, contractors, and the public of the priority your agency or facility places on water and energy efficiency. Ensure water supply, wastewater, storm water issues, and water efficiency BMPs are taken into account at the earliest stages of planning and design for renovation and new construction. Consider developing equipment specifications that target water efficient products so that they are automatically purchased for retrofits, renovations, and new construction. As an example, NASA's Marshall Space Flight Center successfully implemented a product specification for water efficiency plumbing products.
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The water balance described above provides an inventory of water uses and the relative magnitude of each use. For each of these, assess the cost effectiveness of water efficient technologies. Use the water efficiency BMPs as a start to identify possible operations and maintenance, retrofits, and replacement opportunities. Develop a comprehensive list of potential capital improvement projects that reduce water use, noting the cost, potential water savings, and payback of each. This list should provide prioritization to include these projects in the capital planning and budgeting process. Perform a life-cycle cost analysis. The Building Life-Cycle Cost (BLCC) software developed by the National Institute of Standards and Technology (NIST) is one tool for Federal agencies to assess the life-cycle cost effectiveness of energy and water measures. The tool allows for the inclusion of water and wastewater escalation rates.
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Coordination with Facility Environmental Management Systems
Under Executive Orders 13423 and 13514, EMS is the primary management approach for addressing environmental aspects; establishing objectives and targets to ensure implementation; and collecting, analyzing, and reporting information to measure performance. Water management planning and implementation should not be separate and distinct from EMS. Both are part of the same whole. For example, the policy statement and goals discussed above should be consistent with your EMS. The water use information developed here should inform your evaluation of environmental impacts and aspects under your EMS.
The approach you implement for water management should follow the "Plan, Do, Check, Act" model established under your EMS.
- Plan: Develop a water management plan, including establishing goals.
- Do: Implement the plan, including staff training and operational controls. This also includes implementation of projects identified in the opportunity assessment.
- Check: Measure plan implementation.
- Act: Review progress and update the plan as necessary.
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The following resources provide guidance on water best management practices.
North Carolina Water Efficiency Manual for Commercial, Industrial, and Institutional Facilities: Water conservation resource developed and presented by the North Carolina Department of Environment and Natural Resources.
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