If your commercial property has significant landscaping — and most do — you’re probably paying sewer charges on every gallon of irrigation water that soaks into your lawn, waters your trees, and evaporates off your flower beds. A dedicated irrigation meter can fix that, and for properties with substantial landscape areas, the savings justify the investment surprisingly fast.
How It Works
A dedicated irrigation meter is a separate water meter installed on the water supply line that feeds only your landscape irrigation system. Because this water goes into the ground and the atmosphere — not into the sewer system — the utility only charges you the water rate, not the sewer rate. You still pay for the water itself, but the sewer charges on that water disappear.
Without a dedicated meter, all the water entering your building flows through a single meter, and the utility assumes all of it ends up in the sewer. Your irrigation water gets lumped in with your restroom water, your kitchen water, and everything else. The sewer charge applies to the total — including the thousands of gallons per month that are nourishing your landscaping rather than flowing to the treatment plant.
The EPA’s guide to water billing notes that separating irrigation from sanitary water metering is one of the most straightforward ways for commercial properties to reduce sewer charges.
When It Makes Financial Sense
The financial case for a dedicated irrigation meter depends on three factors: your sewer rate, your monthly irrigation volume, and the cost of meter installation. As a rule of thumb, if your property uses more than 10,000 gallons per month for irrigation during the growing season and your sewer rate is above $5 per thousand gallons, a dedicated meter will typically pay for itself within 12 to 24 months.
Consider this example: a mid-size office park irrigates with 40,000 gallons per month during the seven-month growing season. The local sewer rate is $8 per thousand gallons. Without a dedicated meter, the property pays $320 per month in sewer charges on irrigation water — $2,240 per year. A dedicated meter installation typically costs $3,000 to $6,000 depending on pipe size and local requirements. Even at the high end, the payback period is under three years, and the savings continue indefinitely.
Installation Considerations
Installing a dedicated irrigation meter requires a separate water service connection from the utility’s main, a meter pit or vault that meets local code, and usually a backflow prevention device. Most utilities handle the meter installation themselves (you pay for it), while a licensed plumber handles the piping modifications on your property. The process typically takes two to six weeks from application to activation.
Some municipalities require irrigation meters on new commercial construction as a condition of the building permit. If your property was built before this requirement existed, you’ll need to apply for a voluntary installation. Check with your utility’s commercial services department — the process is well-established in most cities.
If your building also has a cooling tower, the irrigation meter and a cooling tower submeter work together to capture the full picture of non-sewer water use. Some facilities achieve their largest savings by addressing both irrigation and evaporation simultaneously through a comprehensive sewer credit application.
The Difference Between an Irrigation Meter and a Submeter
It’s worth clarifying the distinction. A dedicated irrigation meter is a utility-owned meter installed at the property boundary on a separate water service line. It has its own account and its own bill. A submeter, by contrast, is a privately owned meter installed inside your property to measure specific water uses (like cooling tower makeup). Both can reduce your sewer costs, but they work through different mechanisms — the irrigation meter removes water from sewer billing automatically, while a submeter provides data you use to apply for sewer credits.
The Department of Energy’s water management guidelines recommend metering all significant water end-uses separately for both conservation and billing accuracy.
Ready to Find Out What You Could Save?
RPM Water Equity Solutions helps commercial facilities recover money lost to sewer billing assumptions. If your building has cooling towers, you may be paying sewer charges on water that never reaches the sewer system.
Request your free assessment today and find out how much you could recover.
A Simple Investment With Clear Returns
A dedicated irrigation meter is one of the simplest and most predictable water cost reductions available to commercial properties. The installation is straightforward, the savings are calculable in advance, and the meter pays for itself relatively quickly. If your property has significant landscaping and you’re paying sewer charges on every gallon of irrigation water, this is a conversation worth having with your utility provider.
