Surge irrigation is a modification to surface and furrow irrigation systems. Instead of flooding a field continuously, the water is released in surges, as the name implies. This method requires the addition of microprocessor-controlled surge valves. The first pulse of water creates a layer of mud that ``seals'' the soil, allowing subsequent pulses to continue down the field more quickly and uniformly. Adding surge valves to existing systems has the potential to increase efficiency by about 20% (Postel, 1999, 187).