Case study


Case study


Case study

Office building

Case study


Case study


Case study

Office buildings use an average of 14,695 gallons per day of water

This checklist will help facility managers evaluate the appropriateness of water-saving adjustments for improving the efficiency of your building. Remember, water savings often bring energy savings, too.

This information is based on the results of water use evaluations of 26 industrial, commercial and institutional (ICI) facilities throughout the Tampa Bay area. The checklist has been adapted from a publication of the Metropolitan Water District of Southern California.

Many of the water-saving suggestions involve specific equipment. Contact the Southwest Florida Water Management District for information about water-conservation equipment for ICI facilities. This simple checklist can get you on your way to reducing your water use and improving the efficiency of your facilities.

Bathrooms & restrooms

Domestic water use accounts for an average 24% of the water use in most schools.

  • Repair Leaks! A leaking toilet can waste more than 50 gallons of water each day, and a dripping faucet or showerhead can waste up to 1,000 gallons per week!
  • Showerheads, faucets and toilets that must be replaced due to normal wear-and-tear should be replaced with low-volume models, which are widely available.
  • Low-volume showerheads use only 2 gallons of water each minute; older models may use as much as 3 gallons per minute.
  • Replace faucets that use as much as 2.5 gallons per minute with those which use only 1.5. In most cases, low-volume faucet aerators can be installed when the entire faucet does not need replacing.

Water use in toilets can be reduced by:

  • Installing toilet tank water displacement devices, such as toilet dams, bags, or weighted bottles.
  • Retrofitting flushometer (tank-less) toilets with water-savings diaphragms, which save one gallon (20%) per flush.
  • Replacing toilets with low-volume models. Toilets can use as much as 4.5 gallons per flush, while low-volume toilets use only 1.6 gallons per flush. An average savings of about 20% of the total water use in schools was possible through this one water conservation action.

Water use in urinals can be reduced by:

  • Setting urinals with programmable automatic flush valves to a water saving mode that flushes the urinal after more than one use.
  • Replacing urinals with low-volume models. Urinals can use as much as 5 gallons per flush, while low-volume urinals use only 1 gallon per flush.

These Water Conservation at Work suggestions are more than just a good idea. Low-volume water fixtures are also required by most local building codes.

Building maintenance


  • Check the water supply system for leaks, and turn off unnecessary flows.
  • Shut off the water supply to equipment and areas that are unused.
  • Discontinue water circulation pumping in areas not in use.
  • Read water meters monthly. Compare the results to the same month of the previous year. This will help to identify leaks as they occur, as well as monitor your conservation efforts.
  • Check the pressure. Where system pressure is higher than 60 psi, install pressure-reducing valves.
  • Consider using water-efficient ice machines.


Cooling accounts for about 36% on average, of the water use in a school.

  • Reduce excessive blowdown! Many cooling towers operate below the suggested levels of total dissolved solids (TDS) unnecessarily. Adjust boiler and cooling tower blowdown rate to maintain TDS at levels recommended by manufacturers' specifications.
  • Consider using ozone as a cooling tower treatment to reduce water used for make-up.
  • Shut off water-cooled air conditioning units when not needed, or replace water-cooled equipment with air-cooled systems.


  • Instruct cleaning crews to use water efficiently for mopping.
  • Switch from "wet" carpet cleaning methods, such as steam, to "dry," powder methods.
  • Change window cleaning schedule from "periodic" to "as required."


An average of 6% of the water used in schools is used in the kitchen areas.

  • Turn off the continuous flow used to wash the drain trays of the coffee/milk/soda beverage island. Clean thoroughly as needed.
  • Adjust ice machines to dispense less ice if ice is being wasted.
  • Presoak utensils and dishes in basins of water, rather than in running water.
  • Replace automatic shut-off spray nozzles, which can use as much as 4.5 gallons of water each minute, with low-volume nozzles using 2.0 gallons per minute.
  • Turn off food preparation faucets that are not in use. Consider installing foot triggers.
  • Do not allow water to flow unnecessarily. Consider using automatic shut-off faucets at bar sinks.

Dishwasher hints

  • Wash only full loads in the dishwashers.
  • Replace the spray heads to reduce flow.
  • Turn dishwashers off when dishes are not being processed.
  • Reuse the rinse water from the dishwasher as flush water in garbage disposal units.

Outdoor water use


  • Apply water, fertilizer, or pesticides to your landscape only when needed. Look for signs of wilt before watering established plants.
  • Water early in the morning or in the evening when wind and evaporation are lowest.
  • Install an automatic rain shut-off device on sprinkler systems.
  • Consider using low-volume irrigation, such as a drip system.
  • Avoid runoff! Make sure sprinklers are directing water to landscape areas, and not to parking lots, sidewalks, or other paved areas.
  • Adjust the irrigation schedule for seasonal changes. Sprinklers generally do not have to be run as often in cooler weather, or during the rainy season.
  • Use mulch around landscape plants to reduce evaporation and weed growth.
  • Consider using drought-tolerant, low-maintenance plants.


  • Be sure all hoses have shut-off nozzles.
  • Use a broom, rather than a hose, to clear sidewalks, driveways, loading docks and parking lots.
  • Wash vehicles only when needed.
  • Investigate the availability of reclaimed water for irrigation and other approved uses.

Make it a policy

  • Educate employees about the importance and benefits of water conservation.
  • Create water conservation suggestion boxes, and place them in prominent areas.
  • Install signs in restrooms and cafeterias which encourage water conservation.
  • Assign an employee, or a student, to evaluate water conservation opportunities and effectiveness.

Any retrofitting and/or plumbing changes to facilities must be consistent with regulatory agencies. Check with the appropriate agencies before making changes.

View a case study specific to office buildings.

Office buildings use an average of 14,695 gallons per day (GPD) of water

Use Average water use
(% of total)
Potential savings
(% of total)
Cooling 36 7
Domestic 24 12
Kitchen 6
Irrigation 1
Other 33
TOTALS 100% 14,695 gpd 19% 2,792

Source: ICI Conservation in the Tri-County Area of the SWFWMD. SWFWMD, November 1997.

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