Landscape Irrigation: Water Conservation Strategies

An attractive lawn and landscape is a high priority for most organizations. It helps to maintain a good public image and creates a pleasant atmosphere for staff and visitors. These beautiful landscapes come at a high price, however. The increase in water consumption during the summer months for landscape irrigation often puts a severe strain on water supplies in many areas. While water may seem like an endless resource, our population and demand keep increasing while water supply remains constant. By implementing water-efficient landscape irrigation practices, your facility can significantly reduce its water consumption. This will not only lower your water bill, but will help to ensure the future of our nation's fresh water supplies.

No matter what type of landscape you have at your facility, there are two basic rules that apply to water-efficient landscape irrigation:

1. Apply water in the most efficient way possible.
2. Irrigate only when and where water is needed.

Water Saving Practices
The following tips and guidelines, if followed, can improve irrigation efficiency and result in significant and immediate savings:

• Water early in the morning. Wind and temperatures are generally at their lowest levels, allowing water to be applied evenly with little loss from evaporation. This can also lets you complete the watering before there are significant numbers of employees or visitors at the facility.
• Hit what you are aiming at. Position or adjust sprinklers to water grass, plants, and trees. There is no reason to water sidewalks or the parking lot.
• Irrigate deeply (down to 4–6 inches) instead of every day. Deep watering will help plant roots grow deeper and enable them to become more drought tolerant.
• Schedule your watering cycles to reduce runoff and increase absorption. Try to water only as rapidly as the soil can absorb the moisture.
• Do not irrigate when it is windy or raining.
• Avoid over-watering. Measuring moisture at the root level will help to determine when plants need water.
• Raise lawn mowers blades to three inches. A lawn cut higher encourages grass roots to grow deeper, shades the root system, and holds soil moisture better than a closely clipped lawn.
• Avoid using water to clean parking lots, sidewalks, and similar surfaces.

Maintenance and Replacement Options
These maintenance and replacement tips for sprinkler systems, while requiring varying amounts of upfront time and investment, can result in significant long-term reduction in your facility’s water usage:

• Perform an irrigation audit. This is a good way to jump-start any long-term water conservation effort. Irrigation audits consist of three main activities: site inspection, performance testing, and irrigation scheduling. Each activity in itself can result in significant water and cost savings. See the Irrigation Audit Datasheet for a good overview of the process. An irrigation professional can also perform an energy audit for you and recommend energy saving practices. See the U.S. EPA’s WaterSense program Web site to find a certified irrigation professional in your area.
• Increase the efficiency of the system's sprinkler heads. Sprinklers that produce a fine mist are susceptible to water waste from wind drift. Some sprinklers also don't apply water evenly over the landscape. Many times, existing sprinkler heads can be exchanged with more efficient heads designed to minimize the amount of water lost to wind, and distribute water in a more uniform manner.
• Make sure your irrigation system is watering uniformly. Regularly check your system every 2–3 months. Look for water leaks, spray heads popping up, obstructions within the water outlets, and that all of your zones are coming on.
• Install a moisture sensor. Known as tensiometers, these devices automatically test the soil to determine the timing and volume of water to be delivered.
• Install weather-sensing technology so that your plants are watered only when conditions are right. Rain sensors can prevent irrigation from taking place during periods of sufficient moisture. Wind and freeze sensing technology can also interrupt irrigation during inappropriate weather conditions.
• Consider smart sprinkler or irrigation controls. Smart irrigation control technology uses local weather and landscape conditions to tailor irrigation schedules to actual conditions on the site, or to historical weather data. Instead of irrigating according to a preset schedule, advanced irrigation controllers allow irrigation to more closely match the water requirements of plants.
• Consider retrofitting a portion of your trees, shrubs, or plant beds with low-volume irrigation, commonly known as drip irrigation. Many plant beds do not require the spray heads traditionally used to water turf areas. Drip irrigation can be more efficient, due to slow and direct water application to the plant root zones, which minimizes evaporation and runoff.

Landscape Design Considerations
Landscape design and plant selection options are available that can reduce irrigation needs.

• Redesign your landscape to require less water. Convert from high-water-use lawns, shrubs, and trees to water-efficient landscapes, which incorporate attractive plants and require less water.
• Consider using only local plants and grasses. These plants are well adapted to your region's climate and moisture levels and should require less intensive care and watering. Contact a landscape profession or your local Agricultural Extension office for suggestions.
  

Further Reading and Resources
See the Irrigation Association’s Turf and Landscape Irrigation Best Management Practices for a detailed discussion of implementing and managing an efficient irrigation system.