Irrigation Upgrade ROI: How Property Managers Can Tell If a Proposal Will Pay Off

A return on investment calculation needs a baseline. Here is how to build one from your own records and test any irrigation proposal against it.

By Jon Peters, Founder and General Manager, Irrigation Managers

Parts 1 and 2 covered the repair, upgrade or replace decision and the information to ask for before approving a proposal. This part turns a recommendation into a return on investment.

Return on investment compares what the work costs with what it delivers. For irrigation the benefits are lower repair bills, less water lost to leaks and breaks, fewer callbacks, a healthier and better-looking landscape, compliance with local water rules, and for properties that buy water or pump their own, lower water and power costs. Each one can be measured, but only against a baseline. Without one, a promised percentage is just a claim.

Start with what the system is for. The only purpose of an irrigation system is to keep the plants healthy and the landscape vibrant. That is the hardest benefit to put a number on, and the most important one. A proposal that cannot say how it gets water to the plants when and how they need it is only a list of equipment.

Step 1: Establish your baseline

Start with the repair history: what was spent on irrigation repairs over the past several seasons, and on what. Then estimate how much water the site applies. EPA's seasonal comparison method works with 12 months of water bills. Average the months the system is off, multiply by 12 to get annual non-irrigation use, and subtract that from the annual total. In EPA's example, a multifamily property used 890,000 gallons in a year. The non-irrigation months averaged 55,000 gallons, or 660,000 for the year. The difference, 230,000 gallons, is the estimated irrigation use.

It is an estimate. If anything else on the property uses water seasonally, such as a cooling tower or a pool, it is mixed into the number. A dedicated irrigation meter removes the guesswork, and it is the way to measure sites that run on wells or surface water and have no bill to work from.

Step 2: Compare it with your water-use target

This is the water-use target from Part 1: the amount of water the landscape needs over the irrigation season, broken down by month. It starts with the irrigated area, adds historical weather data, then adds the extra water a real system must apply to overcome its own uneven coverage and site constraints.

Inches and gallons are two ways of reporting the same amount once the irrigated area is known: one inch of water over one acre is about 27,150 gallons. Utilities bill in gallons, and applying water is measured in inches.

Here is what that looks like. One irrigated acre in Boise, Idaho, with typical plant demand, the usual rain and a 50 percent allowance for the inefficiency of the system, comes to a target of about 1.67 million gallons for the April through October season, and about 371,000 gallons in July alone. If a property of that size applied 2.4 million gallons (an illustrative figure), the gap of about 725,000 gallons is the opportunity, and it is what every proposal should be tested against. Without a water-use target, you have nothing to measure a proposal against, and nothing to tell you whether the current system is the problem or how it is being managed.

Step 3: Test each line item

Ask which problem each line item solves and what result is expected. EPA's estimates for typical conditions give a starting range.

Replacing a standard clock timer with a WaterSense labeled controller: about 15 percent less irrigation water.
Replacing spray sprinkler bodies with WaterSense labeled, pressure-regulating bodies: more than 20 percent when system pressure is 60 psi or higher. EPA's table runs from none at 30 psi or below to 24 percent at 70 psi or more.
Converting plant beds from spray to drip: 20 to 50 percent less water than spray in those areas.

These are estimates, and results depend on how equipment is programmed and managed afterward. If the property already has a controller with these features, the better question is whether it is set up and run correctly. Apply the figures to your own baseline. Fifteen percent of EPA's 230,000 gallon example is 34,500 gallons. Price it at what your water, or the power to pump it, costs you. On a small baseline that may not repay a large proposal by itself. The rest of the value sits elsewhere: the break that is shut off in seconds, the repair bills that stop climbing, the zone that stops over-applying, the turf and trees that stay healthy.

Step 4: Put a price on the failure you are avoiding

A 1-inch line that breaks can discharge on the order of 35 gallons per minute at about 30 psi, about 50,000 gallons a day. A 2-inch line can discharge about 80 gallons per minute, more than 115,000 gallons a day. That is water and pumping cost, plus the repair, the damage to landscape, paving and foundations, and the plants lost. A leak of 1 gallon per minute, easy to miss, loses 43,200 gallons a month by EPA's figures. Where local rules treat a broken irrigation system as wasteful use, the property can also face enforcement. Flow monitoring with automatic shutoff addresses all of these and produces the record that shows the system performed as scheduled. Value that, and compare it with the cost of the monitoring.

Step 5: Build the phased plan

Put the pieces in order, based on what the analysis shows. Sometimes the first phase is monitoring and control, so a break cannot run unnoticed. Sometimes it is heads, valves or wiring. Sometimes the equipment in place only needs to be programmed and managed properly. Order matters. If the mainline is going to be replaced, that is the time to do the valves, because they connect to it, and new heads should not go on laterals that are about to be replaced. Schedule pipe and larger replacements for when they are needed, and put them in the reserve study so the board funds them over time. Irrigation systems rarely fail all at once, so phasing is normal. Each phase should have its own return and its own measure, and together they should meet the goals of the board. Back the plan with an irrigation repair and maintenance specification, which spells out the exact heads, valves, parts and methods for every repair, so each repair moves the system closer to the goal instead of away from it.

Step 6: Measure the result

After each phase, compare irrigation-season water use with the water-use target, and compare the repair bills with the baseline. Adjust for the weather. A rainy summer should lower use and a hot, dry one should raise it. If use does not follow the weather, that is a sign the system is set and forgotten rather than actively managed. This is why the target is built from historical weather rather than last year's bill. Check for rebates before buying: many utilities offer them for WaterSense labeled controllers, and EPA maintains a rebate finder.

A one-page test for any irrigation proposal

Does it state our current irrigation water use and how it was measured?
Does it state our water-use target, the amount the landscape needs?
Does each line item name the problem it solves and the result expected?
Does it say what is urgent, what can wait, and what the long-term plan is?
Does it address how the system is managed, who will monitor it and receive alerts, and whether that person can assess water use and set a water-use target?
Does it say how the result will be measured after the work is done?
Does it include an irrigation repair and maintenance specification, so every future repair moves the system toward the goal?

This completes the series. Part 1: Should You Repair, Upgrade or Replace Your Irrigation System? Part 2: How Do You Know You Are Getting the Right Irrigation Advice?

A water-use target turns an irrigation proposal into a decision you can defend to your board or owner. If you manage a large irrigated site, the question to ask is how much water your site actually needs. This is not a guess or an estimate based on how much water you used last season. It is based on data. If you don't know your number, chances are you are over-irrigating.

At Irrigation Managers we call our approach AIM: Analyze, Implement, Manage. We map the area that is irrigated and use historical weather data to build a monthly water-use target, then make real-time adjustments to match actual weather and manage the site to our full irrigation season water-use target. Give us a call or send a message. There is no obligation, and we are glad to walk you through it. IrrMgmt.com. 1.800.473.7673.

Common questions

How do I calculate ROI on an irrigation upgrade? Divide the cost of the work by the annual value of the lower repair bills, the water and power reduced, the avoided leak and break losses and any avoided penalties. Each needs a baseline from your own records, so work out what the landscape needs first. The value of a healthy, vibrant landscape is harder to price, but it is the reason the system exists, so judge every line item on how it helps the plants first.

How much water does a smart irrigation controller reduce? EPA estimates about 15 percent for a WaterSense labeled controller replacing a clock timer. Actual results depend on how it is programmed and managed, and are larger on sites that are heavily over-irrigated. Many Irrigation Managers clients see water use drop by 50 percent or more once the site is managed to a water-use target.

How do I find my property's irrigation water use? If you are on a municipal supply or otherwise get a water bill, use 12 months of water bills: average the months the system is off, and subtract that baseline from the irrigation season. A dedicated irrigation meter gives a direct reading and works for sites on wells or surface water.

Sources

U.S. EPA WaterSense, Water Efficiency Management Guide: Landscaping and Irrigation, EPA 832-F-17-016b (November 2017), epa.gov/watersense/commercial-buildings. Includes the seasonal comparison method and example, the 15 percent controller estimate, the spray body table, drip estimates, leak figures and the rebate finder.
Reserve Advisors (a firm that prepares reserve studies for HOAs and condominiums), "Landscaping and Irrigation: Are They Included In Reserve Studies?" (T. Walter, PE; updated April 2026), reserveadvisors.com.
Irrigation Managers, An Irrigation System's Only Purpose, 2026 IRPA Conference, Twin Falls, Idaho, April 22, 2026 (the Boise example in Step 2).