Water Use in Restaurants and Commercial Kitchens

The kitchen typically accounts for nearly half of a restaurant's total water use, according to the U.S. EPA. Inside the kitchen, the dish machine and the pre-rinse spray valve together account for more than two-thirds of the water in most commercial kitchens. There is no single “gallons per meal” figure that fits every restaurant, because menu, equipment age and staff habits move the number a lot. What you can do is learn which machines draw the water, and how to estimate each one.

Where a restaurant's water goes

Restaurants are among the more water-intensive commercial building types, and the kitchen is the main reason. Beyond the kitchen, water goes to restrooms, cleaning, and sometimes landscaping or cooling equipment. The kitchen share is the one owners can change fastest, because it is concentrated in a handful of machines.

Most of that kitchen water is also hot water. Dish rinsing and washing depend on heated water, so every gallon wasted carries a water charge, a sewer charge and the energy used to heat it. That is why efficiency work in kitchens pays back faster than the water bill alone suggests.

Which kitchen equipment uses the most water

Each major draw follows its own simple rule: flow rate times run time, gallons per rack times racks, or gallons per pound of ice. Here is how the main ones compare:

The first two rows deserve the most attention, since they make up most of the kitchen total. The rest of the table is where hidden waste tends to sit: a machine nobody thinks about that runs all day.

Pre-rinse spray valves

The pre-rinse spray valve is the handheld sprayer at the dish pit that blasts food off plates before they go into the machine. EPA states that these valves can account for nearly one-third of the water used in a typical commercial kitchen, and that about one million U.S. food service establishments use nearly 53 billion gallons a year with them.

Federal rules now cap flow by spray force. Since January 2019, new valves must meet maximum flow rates of 1.00, 1.20 or 1.28 gpm depending on product class. Valves flowing at 1.6 gpm or more are the older, inefficient models EPA recommends replacing. Because these valves are cheap and the savings repeat every day, they are usually the best first upgrade.

Commercial dishwashers

Commercial dish machines are rated in gallons per rack, and ENERGY STAR sets a maximum for each machine type: undercounter, door-type, single-tank conveyor and multiple-tank conveyor. In the certified-product listings those limits sit below one gallon per rack, though they differ by type, so compare a machine only against its own category.

Operation matters as much as the label. A machine run half-empty uses the same water per rack as a full one, which doubles the water per dish. Fill racks fully, scrape rather than rinse, keep final-rinse pressure and temperature within the manufacturer's range, and shut the machine off when service ends.

Ice machines and steam equipment

Ice machines use water in two ways: the water that becomes ice, and the water used to reject heat. ENERGY STAR-certified batch machines in the product finder list potable water use of roughly 13 to 20 gallons per 100 pounds of ice. A water-cooled machine adds condenser water on top of that, and models that send cooling water straight down the drain use substantially more than air-cooled ones. Ask for the machine's rated water use in both categories before you buy.

Steam-cooking equipment is the other quiet draw. Steamers, combi ovens and kettles can add substantially to a kitchen's total when water is fed continuously rather than generated inside the unit. Look up the rated gallons per hour on the spec sheet and ask whether a connectionless design is available.

How to estimate your own kitchen's water use

Your water meter gives the total, but not the breakdown. To see which machine is responsible, estimate each one with its own rule, then compare the sum against the meter:

Here is an illustrative example. The run times and machine ratings below are assumptions chosen to show the arithmetic, not measured or published figures. Suppose a spray valve runs about 120 minutes a day over 360 days. At 1.6 gpm that is 1.6 × 120 × 360 ≈ 69,000 gallons a year; at 1.28 gpm it is about 55,000. The difference is roughly 13,800 gallons a year, before counting the hot-water energy saved.

For a dish machine, suppose 150 racks a day over 360 days. A hypothetical older machine at 1.2 gallons per rack would use about 64,800 gallons a year; one rated at 0.7 would use about 37,800. That is roughly 27,000 gallons a year saved. Replace the assumed numbers with your own rack counts and spec-sheet ratings, or use our water calculators for the surrounding math.

Practical ways to cut kitchen water use

Fix the high-flow valves first. Replace any pre-rinse spray valve flowing at 1.6 gpm or more, and test system pressure so the valve delivers the flow it was built for.

Scrape before you spray. Dry-scraping plates and pre-soaking heavily soiled pans cuts spray time, which is the variable you control.

Run full loads and shut things off. Full racks, auto-mode on conveyor machines and an end-of-day shutdown routine all reduce idle and partial-load waste.

Inspect for leaks and scale. A dripping valve or a scaled-up nozzle wastes water silently. Check them on a schedule.

Meter and track. Read the meter at open and close for a week. A rising overnight baseline usually means a leak or a machine left running.

The bottom line

Kitchens drive nearly half of a restaurant's water use, and the dish machine and pre-rinse spray valve make up most of that. Start with the cheapest fix, the spray valve, then compare your dishwasher and ice machine against their category ratings. Measure first, estimate each machine with flow × time or gallons per rack, and let the meter confirm where the water really goes.