Portland Community College
OP-T2-48: Weather-Informed Irrigation

Yes. PCC uses a centrally controlled irrigation management system, which allows us to monitor and control any site from one computer monitoring flow rates to ensure proper watering and monitors weather to know when to water. Maxicom is a hardware and software package that offers genuine central management of irrigation systems. Maxicom manages irrigation systems by sending out instructions, or schedules, and by constantly monitoring feedback to verify the instructions are carried out. Maxicom can monitor current flow, check for breaks or leaks and turn off the offending zone or main line. Maxicom manages flow throughout the entire system to take maximum advantage of available water the long-term benefit is a healthier, more attractive landscape at a reduced maintenance cost. This is accomplished by automatically applying the proper amount of water at the proper time. Many of the more visibly troubling aspects of an irrigation system, such as watering in the rain, broken heads, and watering at inconvenient times are eliminated. Over-watering, and its resulting problems, such as increased susceptibility to disease and decreased playability on sports fields are reduced.

PCC’s weather station gathers minimum and maximum temperatures, wind speed, rainfall, solar radiation, and humidity data. At a user-entered time, the Maxicom system contacts the Weather Station and downloads the data, usually just before the irrigation cycle. Maxicom converts the data to an ET figure, which is used to fine-tune the runtimes of all irrigation schedules. In this way, Maxicom replaces—precisely--the water lost during the previous day to evaporation and transpiration. If schedules are not written to run every day, Maxicom keeps a running total of ET and replaces the total since the last day the schedule ran. PCC also has on site rain gauges. The site Rain Gauge measures rainfall over time in hundredths of an inch and reports that information to the Cluster Control Unit or Site Satellite. Monitoring schedules pause or interrupt irrigation schedules using user-entered thresholds. Systems with multiple sites can have Site Rain Gauges at each site for maximum accuracy. Site rainfall data can also be used to fine tune ET for a site when its associated weather station is at a remote site.