Smart Controllers are no Silver Bullet

John OssaHigh-efficiency landscape water management can be critical to growing your irrigation and landscape business. All over the country, increasing demands on unpredictable or scarce water supplies require the landscape industry use water more efficiently. As a nation we have great faith in technology and love a quick fix. Seeing a need, technology entrepreneurs have contributed to developing so-called SMART controllers. Once programmed with key, site-specific parameters, these controllers are self-adjusting according to weather inputs gathered from weather stations via the Internet or on-site weather or soil moisture sensors.

Now that these controllers have been deployed for a period of time, some things have become very clear. SMART controllers are no silver bullet, no magic box. There is no way around the need for irrigation and landscape professionals to understand the basics of landscape water management. More specifically, if a contractor does not understand the basics of soil/plant/water relationships, and does not truly understand the actual inefficiencies in how water is distributed by any irrigation system, installing a SMART controller will only automate a sub optimum result.

The recent study released in May 2009 by the California Department of Water Resources entitled “Evaluation of California Weather-Based ‘SMART’ Irrigation Controller Programs” made this very clear. Quoting from the report: “While the overall findings show reductions in water use through the installation of smart controllers, it is also significant that 41.8 percent of study sites experienced an increase in weather-normalized irrigation application after the installation of a smart controller.” Without understanding, any tool can be used incorrectly. The new tools are potentially wonderful in the hands of knowledgeable operators, but we cannot skip the step of understanding the basics in the rush to deploy a silver bullet.

What are the basics that will help a landscape professional get the most out of the new technology and thereby build his or her business? Start with shaping the expectation of the customer. Accurately defining the expected outcome can be half the battle. The desired outcome is higher system efficiency, which leads to reduction in water use and a healthier landscape. Explain to the customer all of the areas for potential efficiency gain are part of this equation. Consider a three-part proposal:

• The first part is to ensure that all of the existing hardware is operating at its best on the system. In other words, do a diagnostic of existing system condition and repair broken or dysfunctional hardware.
• The second portion of the proposal could be optional, although depending on the existing system, highly recommended. Propose doing a system renovation targeting correct operating pressure and head spacing. Pressure and spacing are often the two greatest opportunities to improve distribution uniformity.
• The third part of your proposal is installing a SMART controller to make daily adjustments to irrigation scheduling to hit the moving target of changing plant water requirements dictated by weather.

Spend time explaining to your customer that their landscape has a variety of plants with differing plant water requirements. Those same plants have water needs that increase to a peak need during June/July, and decrease toward fall and winter. What that means is there is never a fixed schedule of irrigation that is “right” from day to day. Include in your proposal plenty of time for the accurate calibration and subsequent fine-tuning and adjustment of parameters such as soil type, root depth and system efficiency (this is a critical step and may require multiple site visits). Once accurate “base-line” data have been installed, you have completed the basics and have reasonable assurance of success.