A green lawn can still be wasting thousands of gallons of water. Wet sidewalks, dry patches between sprinkler heads, puddles at the curb, and unusually high water bills are all signs that a system is running without delivering water where it belongs. Knowing how to assess irrigation efficiency helps property owners catch those problems before they damage landscaping or increase monthly costs.
An efficient irrigation system applies the right amount of water, in the right places, at a rate the soil can absorb. That sounds simple, but sprinkler performance changes over time. Heads get blocked, nozzles wear out, pipes leak, plant growth interferes with spray patterns, and controllers may keep running on an outdated schedule.
Start With a Visual Irrigation Inspection
Run each irrigation zone during daylight and walk the property while it operates. This is the fastest way to find obvious waste and coverage problems. Watch the entire zone, not just the first few heads you see. A broken component on the far side of a yard can waste water every time the system runs.
Look for sprinkler heads spraying pavement, siding, fences, or vehicles. Some overspray is easy to correct by adjusting the arc or replacing the nozzle, while other situations require moving a head or changing the nozzle type. Water should stay within the landscaped area as much as possible.
Also look for misting. A sprinkler that produces a fog-like cloud instead of defined streams is often operating under excessive pressure or has a damaged nozzle. Fine mist can drift away in a light breeze before it reaches the root zone. Low pressure creates a different problem: short spray patterns and dry areas near the edges of the zone.
Check for pooling around sprinkler heads, soggy ground, water bubbling from the soil, or a zone that continues dripping well after it shuts off. These conditions can point to cracked pipes, damaged fittings, leaking valves, or drainage problems. If water appears when the system is off, shut down that zone if possible and arrange for a professional inspection.
How to Assess Irrigation Efficiency With a Catch-Can Test
A catch-can test shows whether a zone is applying water evenly. You do not need specialized equipment for a basic test. Use several straight-sided containers of similar size, such as clean tuna cans or irrigation catch cups. Place them across the watering area, including spots near heads, between heads, and at the outer edges of coverage.
Run the zone for 15 minutes, then measure the water in each container. If one container has much more water than another, the system has uneven distribution. Major differences often come from clogged nozzles, tilted heads, incorrect spacing, mismatched nozzle sizes, pressure issues, or obstructions such as shrubs and grass.
Multiply the average water depth collected in 15 minutes by four to estimate the zone's precipitation rate per hour. For example, an average of one-quarter inch in 15 minutes means the zone applies about one inch per hour. This gives you a useful reference for setting runtimes instead of guessing.
Uniformity matters as much as total output. If one part of a lawn gets enough water but another stays dry, extending the runtime usually makes the wet area wetter without solving the real issue. Repairing or adjusting the zone is the better path. A properly designed zone should use matched sprinkler types and nozzles so water is distributed consistently across the area.
Check Whether the Soil Can Absorb the Water
Even coverage is not efficient if water runs off before it can soak in. Watch the ground during a normal watering cycle. Runoff is common on slopes, compacted soil, clay-heavy ground, and areas with long runtimes or high-output nozzles.
If water starts flowing into the street, driveway, or drain before the zone finishes, the cycle is too long for that soil condition. A practical adjustment is cycle-and-soak watering. Instead of running one zone for 20 minutes straight, run it for two 10-minute cycles with a pause between them. The break gives water time to move into the soil.
This approach is not a fix for every problem. Persistent runoff may also indicate poor grading, incorrect sprinkler selection, excessive pressure, or a damaged component. Newly planted areas can need different scheduling than mature turf, and drip irrigation may be a better fit for beds, shrubs, or narrow planting strips.
Compare Watering Time to Plant Needs
Irrigation efficiency is not just about using less water. Underwatering can weaken turf, stress trees, and leave landscape beds vulnerable during hot weather. The goal is to avoid both waste and water stress.
Check the soil several hours after watering. For most lawns, moisture should reach several inches below the surface rather than sitting only at the top. A screwdriver or soil probe can help you check depth. If it slides into the soil easily to the root-zone depth, the lawn likely received a useful soak. If the surface is wet but the soil below is dry, consider a longer total watering time split into shorter cycles.
Your schedule should also change with weather. A controller that runs the same program through spring, summer, fall, and periods of rainfall will waste water. Reduce watering during cooler or rainy periods and increase only when heat, wind, soil conditions, and plant needs justify it. Watering before sunrise generally reduces wind loss and gives foliage time to dry.
Avoid judging plant needs by the clock alone. Shade, sun exposure, soil type, and sprinkler output can vary across one property. A sunny slope may need a different schedule than a shaded lawn area, even when both are part of the same landscape.
Use the Water Meter to Find Hidden Leaks
A water meter can reveal leaks that are not visible above ground. First, make sure no water is being used inside or outside the property. Turn off irrigation at the controller, avoid running appliances that use water, and check the meter's leak indicator or small flow dial. If it continues moving, water may be escaping somewhere in the plumbing or irrigation system.
To isolate the irrigation system, shut off its supply valve if one is available and check the meter again. If the movement stops, the irrigation system is a likely source. A slow leak may not create a wet spot right away, especially if it is underground, but it can still raise water use and erode soil around pipes.
A meter test does not identify the exact repair. It does tell you when a closer inspection is worth scheduling. Underground leaks, valve failures, and wiring issues are best diagnosed with the right tools before digging or replacing parts.
Review Zones, Heads, and Controller Settings
Each zone should water a similar type of landscape with similar water needs. Mixing spray heads, rotors, and drip irrigation in the same zone is a common source of uneven watering because these components apply water at very different rates. The controller may be working correctly, but the zone design may not be.
Inspect heads for level, clearance, and correct direction. Grass that has grown over a spray head can block the pattern. A head sitting too low may be affected by soil or turf, while a head sitting too high is easier to damage with mowing equipment. Replace missing filters and damaged nozzles rather than trying to compensate with extra runtime.
At the controller, confirm the current date, time, seasonal adjustment, start times, and zone runtimes. Multiple start times can accidentally make a full program run more than once. If a zone runs at an unexpected time, the issue may be programming rather than a valve problem. A rain sensor should also be checked to make sure it is connected and functioning as intended.
When a Professional Assessment Makes Sense
Home checks can identify many visible issues, but certain problems need a full irrigation evaluation. Call for service when zones have weak or inconsistent pressure, a valve will not shut off, the water meter suggests a leak, sprinklers have widespread poor coverage, or the controller will not operate zones reliably.
A professional can test pressure and flow, inspect valve operation, evaluate nozzle selection, identify buried leaks, and determine whether a repair or system update makes better financial sense. For a property with repeated dry spots or runoff, the right solution may be a targeted adjustment rather than a complete replacement. In other cases, aging components and poor zone layout make an installation upgrade the more dependable option.
ASM Irrigation provides same-day consultations and estimates for irrigation repairs and installations, helping property owners move from a suspected problem to a clear scope of work without unnecessary delay.
A short walk-through during a scheduled watering cycle can prevent a small adjustment from becoming a dead lawn, a high bill, or a larger repair. Check the system before peak watering season, then act quickly when the water is not landing where it should.