Water conservation in irrigation has become an increasingly popular topic due to water restrictions and the costs associated with water and energy consumption. As a direct result of these concerns, improvements have been made not only in available equipment, but also in irrigation system design principles. Combined, these changes prove that dramatic reductions in usage and costs can be realized.

In the past, an irrigation system often was thought of as a necessary evil that robbed construction funds from the landscape budget. Its real importance as a management tool was overlooked and one of the first items cut when reductions were implemented. When a modern irrigation system is properly designed, installed and maintained, however, it proves to be a management tool that allows the landscape staff to actually save labor, energy and money.

Just as plastic piping revolutionized the industry 25 years ago, state-of-the-art electronics are revolutionizing the industry today. Although solid-state controllers were introduced more than 10 years ago, many people still shy away from them because of programming difficulties in the earlier models. Today’s controllers are as easy to program as a microwave oven or alarm clock and can retain program memories for days after major power outages, providing the accurate timing that should be demanded from a system. On large sites, such as parks and golf courses, the control system is often linked directly into a weather station that monitors evapotranspiration (ET) rates, adjusting the system to perfectly program output to match the ET rate.

Pump station manufacturers have seen an increase in industry competition. This forces them to provide increasingly efficient pump stations and controls, thereby reducing the user’s energy costs. Computer control circuits and surge-protected, solidstate electronic equipment provide reliability and precise control of the pump’s sequence cycle, system flow, and/or alarm and emergency functions. Solid-state flow and pressure transducers provide continuous, accurate data to the computer circuit. Today, pump controls are usually compatible with most modern computer-based irrigation controls and can provide instantaneous digital displays of flow, pressure and total volume used. An irrigation consultant can assist in analyzing an irrigation system and help select pumps, motors, automatic valves, and coordinate controls that will reduce the cost of operations and save money year after year.

In parks and golf courses, the large 80’to 120’ radius rotor sprinklers used in the ‘60s and ‘70s required pressures of 80-100+ psi. These have fallen to the side of the road. The more economical 65’ radius rotors that work at 60-65 psi not only save 25% or more in energy consumption, but provide the user with more uniform distribution and superior water management control.

Because it is incumbent upon the designer to be informed, the real saving is in the irrigation design. Irrigation has become increasingly sophisticated, and the need for professional services covering all aspects of irrigation design has also grown. Today, approximately one-third of landscape site development budgets go to irrigation systems. If the designer is not involved with irrigation on a day-to-day basis, unfamiliarity with new advances in this field could result in a system quickly becoming obsolete.

Many Landscape Architects are not overly concerned with irrigation because it is considered a “minor” part of their entire project scope. In some offices where irrigation designs are produced in-house, it is passed on to the least experienced person when it actually should be done by the most experienced person. This is where the Professional Irrigation Consultant assists the Landscape Architect the most, not only by freeing the LA of this burdensome task, but by allowing the LA to concentrate on other aspects of the project.

The irrigation consultant, being a fulltime professional, is informed of the latest industry developments and can provide the client with the newest technology in design and equipment selection. The Landscape Architect can justify the cost by recognizing that responsibility to the client has been fulfilled by protecting the client’s investment and providing the best service possible.

Now, electronics are the latest developments in the design field. Increasing numbers of designers are using CADD systems. Other technologies, such as Denso-grams and computer analysis of sprinkler test results, also are rapidly becoming available. These new technologies allow consultants to test drive a system while it is still on the drawing board. They also enable designers to obtain scheduling coefficients and make changes to the design to improve efficiency. This results in savings to the client and demonstrates the professionalism of the irrigation industry and the Landscape Architect involved in the project.

To be of real service, an irrigation consultant should be brought on board early in the design stage. The consultant can assist by working out water requirements, water source development and electrical requirements, and work with the project’s other design consultants. During installation, the consultant can spot problem areas that the untrained eye may overlook and ensure that the system is in its peak condition at the time it is accepted. Once the irrigation system is installed, the consultant should work with the client on water management programs that optimize water consumption seasonally, which result in drastic water and energy savings for years to come.

The owner of Irrigation Hawaii, Allan Schildknecht has been an irrigation consultant for 19 years. He is a member of the American Society of Irrigation Consultants, the ASLA, the Hawaiian Turfgrass Assoc. and the Landscape Industry Council of Hawaii. He is editor of the Hawaii Chapter ASLA Executive Committee Newsletter.