This type of audit you don’t need to be afraid of, even if you do get soaked. A lawn sprinkler audit done annually is one of the best home improvement investments you can make so your lawn stays lush and your water bills stay low.
“Nationwide,” according to the U.S. Environmental Protection Agency, “landscape irrigation is estimated to account for nearly one-third of all residential water use, totaling nearly 9 billion gallons per day.”
And as much as 50 percent of that irrigation may be going to waste, due to inefficient or improper watering, the EPA says.
When to audit
Auditing your irrigation system to make sure it’s working well can be done anytime weather permits, but early spring is an especially good time since it comes before your lawn’s growing season. As far as what part of the day, early morning is the best time to test your sprinkler system. The sun isn’t yet at its peak, so you won’t lose much water to evaporation, and water pressures are high.
Big-picture considerations for a sprinkler system
There is more to a lawn irrigation audit than checking hoses and sprinkler heads for leaks. First, experts advise, take a step back and figure out what you have and what you need.
Your lawn’s size in square feet and shape will heavily influence your watering decisions. If the area is compact and rectangular, a simple hose-end oscillating sprinkler may be all that is needed.
There are three main types of soil, each with different watering requirements:
- Clay soils: Require less watering because they hold the most water. Because water seeps slowly into clay soils, water at low rates over a longer period.
- Sandy soils: Water passes through sandy soils quickly., so water more frequently but for shorter periods of time.
- Loam soils: These lie in-between sandy and clay soils in their moisture retention, so take a medium course — moderate watering over a moderate period.
Grass types influence watering needs
Grasses vary greatly in their drought tolerance. The more tolerant they are, the less water they will need
|Drought tolerance of common types of grass|
|Warm-season grasses||Cool-season grasses|
|Good||Bermudagrass, Zoysia japonica, Seashore paspalum||Tall fescue|
|Fair||St. Augustinegrass, Centipedegrass, Bahiagrass||Kentucky bluegrass|
|Poor||Zoysia matrella||Bentgrass, rough bluegrass, perennial ryegrass|
|Sources: Texas A&M University Extension Service, Cornell University Sports Field Management|
Conducting your lawn sprinkler audit
The goal is to achieve lawn irrigation to a depth of six inches. Here is how you figure out how much to water, and how to adjust your sprinkler system to achieve that six-inch depth.
- Place cups or cans at various spots around your lawn. There are specialized “catch cans” designed for the job that you can purchase online, from some county extension service offices or water utilities. Shallow-sided cans, such as tuna or cat food cans, or even milk cartons with their tops cut off, do best for this test.
- Evaluate your spray patterns and adjust and replace your sprinkler heads and relocate other sprinkler devices until the cans are catching a relatively even amount of water. Fix any cracked or clogged sprinkler heads.
- Water for a half hour.
- Measure the water in each watering can, and average them.
- Take soil probe or a spade and note how deeply the lawn was watered.
From the two figures — the average amount of water and the depth of saturation — you should be able to figure out your desired watering time.
For example, if a half hour of watering filled your cans to an average of 0.5 inches, and moistened the soil to 3 inches, you know you’ll need to water for an hour to get the water to soak 6 inches down.
If you also have a drip irrigation system, check it as well. There may be some wear and tear that calls for the replacement of parts. This would be a good time to flush out the system, as the No. 1 problem with drip irrigation systems is an accumulation of dirt that causes clogs.
Some water utilities offer free sprinkler audits
Your water utility has an interest in preserving water, so much so that many public and private services offer sprinkler evaluations at no or low cost.
Free programs are offered in many cities and counties across the United States, including
In Colorado: A consortium of 30 water districts, including those serving Denver, Boulder and Fort Collins.
In Utah: Counties around and including Salt Lake.