Sweetwater Wetlands Mosquito Abatement

Tucson Water is a partner in local efforts to protect residents from the West Nile and Zika viruses. Both can be transmitted to humans through bites of infected mosquitoes. To avoid being bitten while at the Sweetwater Wetlands:

  • Limit your visit around dawn and around dusk. Mosquitoes are most active during these times.
  • Wear long sleeve shirts and pants when possible.
  • Use protection by applying mosquito repellents that contain DEET, Picaridin, or Oil of Lemon Eucalyptus.

The wetland ponds contain areas of deep, open water alternating with zones of shallow water planted with bulrush and cattail. Shallow vegetated zones are prone to produce mosquitoes, which are potential carriers of the West Nile and Zika viruses.

To avoid a potential public health risk, the City of Tucson has a mitigation program to control the mosquito population at the Sweetwater Wetlands and protect visitors from potential threats:

  • Staff applies bacterial larvicide (AQUABAC and VectoLex) to the ponds to stop mosquito larvae from growing into adults on a regular basis.
  • This larvicide is specific to mosquito larvae and does not harm any of the other wildlife or the habitat itself.
  • To kill adult mosquitoes, Tucson Water implements fogging at 11 p.m. every three days during the monsoon season since mosquitoes thrive in higher humidity.
  • Every spring, Tucson Water and the Tucson Fire Department conduct a controlled burn that reduces mosquito habitat.

In addition to the Mosquito Abatement Program at Sweetwater Wetlands, monthly monitoring of adult mosquito populations takes place at Tucson Water's CAVSARP and SAVSARP facilities in Avra Valley. Additional mosquito-related information includes: