Irrigation control systems and method of operating an irrigation system are described for irrigation systems including one or more orifices, e.g., sprinkler heads, arranged in one or more irrigation lines. The control system can include one or more sensors such as moisture meters and flow meters that measure water output associate with the irrigation system. The irrigation control system can be linked to one or more networks for access, e.g., through the Internet. The control systems and methods can utilize moisture calibration to avoid or reduce a need for continuous use of moisture sensors.
