Vertical drainage was shown to be an effective method for the elimination of mosquito breeding sources under certain soil profile conditions. Drainage holes were effective where drilling penetrated through a highly impermeable stratum (e.g. clay or hardpan) into sand or loamy sand strata. For fields with no highly impermeable stratum within a meter of the surface, vertical drainage was not necessary and careful water management would eliminate mosquito breeding. Prolonged excessive irrigation and lateral, subsurface saturation from adjacent sources of water negated the benefits of drilling. The use of rate of infiltration (RI) values as described can prove very important in the determination of the cause for long-standing water.