The present disclosure is generally directed to an adjustable speed irrigation system having a control panel, at least one water conduit, at least one tower, and a position sensor. A user inputs a user-defined end destination at the user-defined arrival time into the control panel. The control panel receives a current position of the irrigation system from the position sensor. The control panel compares the current position to the user-defined end destination and calculates a new optimum ground speed required to reach the user-defined end destination at the user-defined time based on the current position of the irrigation system. The control panel then sends a signal to a speed control unit to adjust the speed of the irrigation system to match the new optimum ground speed.
