The Sweetwater Wetlands is closed to the public one day a year. In early March (early November in 2021), Tucson Water and the Tucson Fire Department conduct a controlled burn to remove dead and thatched bulrush and cattail, which, if not removed, will eventually stifle new spring growth.
The annual exercise also provides new fire staff with valuable training and experience controlling fast-moving fires months before the normal wildfire season begins. The dead, thatched vegetation must also be removed to allow applications of granular mosquito larvicide to contact the water, which greatly improves the effectiveness of Tucson Water's Mosquito Abatement Program.
Above: Video of the annual controlled burn on March 8, 2018.
Important Facts About Annual Controlled Burn
- The roots of the bulrush and cattail remain viable during the burn and the vegetation quickly grows back within three to four months.
- No more than one-third of the Wetlands is burned in any one year to leave plenty of healthy habitat during the remaining winter migratory bird season.
- The burn is scheduled early enough to avoid April black bird nesting.
- Local wildlife and animal experts are onsite in case their assistance is needed.
- On the day of a burn, migratory water fowl typically lift off at the first sense of fire and return to the open ponds after the fires have burned out in the late afternoon.
- The Sweetwater Wetlands reopens to the public the next day.