Alice Springs experienced high summer rainfall between January and March 2010, resulting in PWC discharging large volumes of effluent into the Ilparpa swamp A area. ME carried out an aerial mosquito larval control operation in Ilparpa swamp in March, and adult mosquito numbers remained relatively low as a result of this control operation. This control operation was assisted by the efficient drainage of rainwater and effluent out of the swamp via the Ilparpa OUD into St Mary’s Creek. However, the lack of drain maintenance is of great concern, as vegetation growth and silt deposits might hinder the efficient operation of the drainage system in the future. Thus, it is very important to resolve the issue of drain maintenance, and potentially enhance the drainage system to ensure efficient drainage of the swamp in the future to minimise the potential for arbovirus borne disease. Additional rain and effluent release in April did not lead to increased mosquito numbers. Culex annulirostris numbers decreased to very low numbers in Ilparpa swamp by 28th April 2010.