If you received your report from a Slow the Flow consultation and were wondering what all of the test results at the bottom mean, look no further. Below you’ll find an overview of all of the tests results, what they mean, and how your system matches up to the ideal results.
Precipitation rate (PR) is a measure of how many inches of water per hour your irrigation system is applying. Different head types have different precipitation rates. The precipitation rate determines how long you need to run your sprinklers. The ideal range of Precipitation Rates for spray heads is between 1 and 1.5 inches per hour. The normal range of Precipitation Rates for rotor heads is between 0.7 and 1 inch per hour. But if your PR falls outside of these ranges and you have a relatively high Distribution Uniformity, no worries, we took that into account when programming your schedule.
The distribution uniformity (DU) is a measurement of an irrigation system’s ability to apply water uniformly over the surface of a landscape. Since the amount of water put out by an irrigation system is not completely uniform, some parts of the landscape will receive more water than others. Minor adjustments to most systems can improve distribution uniformity and green up the dry spots. Ideally, Distribution Uniformity should be between 40%-70%. Anything under 40% is too inefficient and would require adjustments to the system in order to fix before recommending a new schedule. If you have a Distribution Uniformity above 70%, your system is in great shape and running very efficiently!
On average a lawn requires 27 inches of water per square foot over the course of the watering season, while shrub beds require 18 inches of water per year. The water usage estimate that we provide is based on your landscape size, the amount of grass area and non-grass areas, and average weather for the Front Range.
Most sprinkler heads apply water most efficiently at a water pressure between 20 and 30 PSI (pounds per square inch) for spray heads and 25-80 PSI for rotor heads. Sprinklers cannot cover the desired area if the pressure is either too low or too high. If your pressure is low, try watering when less people are watering or modify your system so there are fewer sprinklers on each valve. High pressure causes misting and wears out your sprinklers faster. If your pressure is high, pressure regulating heads or a pressure regulator can be installed to lower pressure, minimize misting, and maximize irrigation efficiency.
For a healthy lawn, roots should be 6-12 inches deep. This is accomplished by deep, infrequent watering, which greatly enhances your lawn’s ability to withstand extreme temperatures and increased intervals between watering. So if your grass root depth is below this range, our recommended watering schedule using Cycle and Soak will help to get those roots a bit deeper.
Clay is the most common soil type that we find along the Front Range and it absorbs water at a slower rate than Sandy or Loamy soils. The Cycle and Soak method that we recommend when creating your watering schedule improves absorption of water that’s applied, especially in Clay-rich soils.