Water Conservation Experiment

Post date: 01-03-2012

In a quest to gather hard evidence that smart irrigation products do in fact save resources, the Green Team for the Borough of Avalon, N.J. collaborated with their Public Works Department, Hunter Industries, Toro, John Deere Landscapes, Garden Greenhouse and Nursery, and Exclusive Land Design to develop a water conservation experiment.

The group started with three median islands similar in size and plant material. Each island was then fitted with a different irrigation system to learn which configuration could save the most water while maintaining healthy turf.

New sod was installed on the first island, and the irrigation system contained a rain sensor, 30 traditional spray heads and 15 half nozzles, which use 1.8 gallons of water per minute. The plan called for the new sod to be watered for 20 minutes per day.

The second island was also fitted with new sod. The irrigation system used the existing water lines and spray heads, but the nozzles were replaced with water-conserving rotary nozzles. These are designed to spray a bigger water droplet to avoid wind drift and to apply water at a slower rate, allowing for better soil absorption. An ET sensor was utilized to increase or decrease run times based on the weather.

The third island featured a drip irrigation system. Requiring more preparation, six inches of soil had to be removed and replaced with screened topsoil mixed with leaf compost. Tubing that emits one gallon of water per hour was installed every 12 inches across the island. The island was then covered with new sod.

The median island transformations were completed in March 2011 and after a few months of allowing the sod to take root, the experiment began. Several soil tests were taken to ensure the islands were healthy and that overwatering was not necessary.  The irrigation systems were turned on at the beginning of May and measurements on both the water usage and grass blade height were taken weekly. By the end of September, the team had gathered enough data to evaluate the results of the experiment.

  • Island 1 water consumption averaged 4,146 gallons weekly.
  • Island 2 consumed an average of 2,494 gallons of water per week.
  • Island 3 used a weekly average of 9,989 gallons of water.

The results clearly showed that island 2, fitted with the smart irrigation system, had the most efficient use of water. Island 3 showed that although drip irrigation can be very efficient, the best utilization of drip might not be in turf zones.

Jim Collins, Green Team Chairman, was pleased with the experiment, stating, "We have learned beyond a question of a doubt that rain sensors and so-called 'smart systems' definitely reduce the volume of water needed to provide green, healthy grass."

John Deere Landscapes Branch Manager Ron Brown, who assisted with the experiment, reflected, "Doing hands-on research makes a huge difference compared to reading numbers and theories. I have found myself more enthusiastic about introducing new water-saving products and features to the contractors that visit our store."

In response to the experiment results, the Borough of Avalon is now re-examining all of their current outdoor water use rules and codes. This will lead to future water conservation for the Borough and possibly neighboring communities as several have been keeping a close eye on Avalon's experiment.