City of St. Paul Park 

Summer lawn watering creates large demands on local water utilities.  Water supply treatment and storage facilities are often built two, three and even four times larger to supply additional demands created by lawn watering.   This extra capacity is not used for most of the year and adds significant costs to the design, construction and operation of the water system.  Water customers and communities can save money by using water more efficiently.  These water efficient lawn watering practices can help maintain a beautiful yard and conserve valuable supplies.

General Information

• Adjust sprinklers to water only grass areas and not impervious surfaces such as streets, driveways and walkways.
• Mow grass to a height of 2 1/2 to 3 inches.  Taller grass shades the roots and soil surface, which helps reduce the amount of water that is lost to evaporation.
• Use sprinklers that spray low large drops vs. high fine ones.
• Use hand held soakers for small trees, shrubs and plants.
• Use shut-off nozzles on hoses and repair leaky hoses and fittings.

When to Water

• About one inch of water per week (including precipitation) is adequate for maintaining a healthy lawn.   Use a can or rain gauge to help determine the amount of water applied by the sprinkling system and supplied by rainfall.
• Don't use a fixed schedule for lawn watering.  Apply water only when it is needed.  Over watering can promote diseases and affect the health of the lawn.
• A simple test for determining if grass needs water is to walk on the lawn and if you leave foot prints, it may be time to water the lawn.
• Using a spade or gardening tool to check soil conditions 2 to 6 inches below the surface can provide information on soil moisture and the need to water.
• A good soaking once or twice a week is better than watering every day.  Allowing the soil to dry between watering will allow the roots to grow to greater depths and help make turf more drought tolerant.

Best Times for Lawn Watering

• Water during the cool part of the day to minimize water lost to evaporation.  Early morning hours (4 a.m. to 8 a.m.) are the best, and peak water consumption hours (4 p.m. to 9 p.m.) should be avoided.
• Avoid watering during midday hours when it is hot and sunny to prevent scalding the turf.
• Watering at night is not recommended because the lawn stays wet for a long period of time, which can promote diseases and affect the health of your lawn.
• Avoid watering during rainy or windy weather conditions.

Automatic Lawn Watering Systems

• An automatic timer is part of most buried sprinkler systems, but can be added to any sprinkler system for a very low cost.  Automatic timers make it easy to set sprinkling systems to apply specified amounts of water during the best times of the day.
• Set systems to turn on between 4:00 a.m. and 8:00 a.m.
• Set the system to turn on for three 10 minute sessions with each session 1/2 hour apart to improve water infiltration and reduce runoff.
• Equip the system with moisture sensors so the system does not run when it is raining.
• Set the automatic timer to water every 3 to 4 days adjusting the time and frequency, as needed, to accommodate changes in seasonal water demand.

Watering Restrictions

Local watering restrictions are sometimes necessary due to limited treatment capacity or reduced water supplies caused by mechanical problems or drought conditions.  Water efficient lawn watering practices can help reduce the need for watering restrictions and expensive expansions to the water system.  Here are a few recommendations in the event lawn watering restrictions are needed.

• Water less frequently and gradually reduce the amount of water.  This will help reduce stress and condition the turf if a total ban on lawn water becomes necessary.
• Reduce the amount of foot traffic allowed on the lawn as much as possible.
• Allow the grass to grow longer to reduce moisture loss from the soil.

New Lawns and Landscaping Alternatives

• Adding organic matter before seeding will help improve water and nutrient retention.
• Reduce water requirements by using the drought-tolerant grass seed and sod.
• Reduce turf areas by planting drought-tolerant trees, shrubs, and plants.