Using the Lawn Watering Guide

The daily Lawn Watering Guide is designed to help you use the right amount of water on your lawn.

The guide lists how many inches of water a lawn needs. Cumulative totals are given for three, five and seven days. When the total reaches one-half inch, it’s time to water.

Lawn watering accounts for nearly half of the water used annually by most homes, and up to 70 percent of water demand on a summer day. Lawns are often watered too often and sprinklers are left on too long.

A lawn loses water through evapotranspiration (ET) and is replenished through rainfall and sprinkling. The ET rate tells how many inches of water a typical lawn uses through surface evaporation and plant transpiration. ET is calculated based on temperature, humidity, wind and sunshine. Watering guide amounts are based on the ET rate for bluegrass, minus any effective rainfall.

To find out how much water your sprinklers apply to the lawn, sign up for a free sprinkler system audit. You can also measure sprinkler output for each zone or station with three steps:

1. Randomly place six soup cans of equal size within the spray of the sprinklers.
2. Turn on the sprinkler for 10 minutes.
3. Pour all the water from the cans into one can. Measure the depth of the water. The result is the “inches per hour” that your sprinklers are delivering to that zone.

Use this formula to find how many minutes it will take to deliver half an inch of water: Divide half an inch by “inches per hour” and multiply by 60. For example, if a zone delivers 2 inches per hour, it would take 15 minutes to apply half an inch.

Learn about waterwise lawn care, other water conservation tips or contact Fort Collins Utilities for more information.