Patent ID: 8606415

Claim:
An evapotranspiration (ET) based irrigation system, comprising: a stand alone irrigation controller including a control panel including a display and a plurality of user inputs that enable a user to enter a watering schedule including a run time, and to manually adjust a percentage adjustment value of a percentage adjustment feature, said percentage adjustment feature configured to change said watering schedule by said percentage adjustment value; a computer processor operatively connected to the control panel; a memory operatively connected to the computer processor; a plurality of switches operatively connected to the computer processor for turning a power signal ON and OFF to a plurality of valves that deliver water to a plurality of sprinklers; and programming stored in the memory to accept input from the user via the plurality of user inputs to implement the watering schedule, wherein during said run time, the computer processor operates ones of the plurality of switches to turn the power signal ON to one or more of the plurality of valves thereby delivering the water to ones of the sprinklers to irrigate an irrigation site, the programming further accepting input from the user via the plurality of user inputs to implement said percentage adjustment feature to increase or decrease the run time of the watering schedule by the percentage adjustment value; a stand alone weather station different from the stand alone irrigation controller including at least one environmental sensor; a soil moisture sensor; and a stand alone ET unit different from and operatively in communication with the stand alone irrigation controller, the soil moisture sensor, and the stand alone weather station, the stand alone ET unit including a memory storing programming that, automatically increases or decreases said percentage adjustment value of the percentage adjustment feature in response to the at least one environmental sensor, and communicates a command to the computer processor of the stand alone irrigation controller to automatically inhibit irrigation when a level of soil moisture detected by the soil moisture sensor is above a threshold.