Mosquito risk in rainwater tanks

With dengue fever already reported in far north Queensland, the mosquito-awareness campaign is sure to be prevalent this summer.  As in the past, we can expect the dire predictions regarding the role of rainwater tanks in the spread of mosquito-borne disease.

Truth is that well-maintained tanks pose no greater threat – perhaps even less – as mosquito breeding sites than the myriad of water-pooling opportunities present in the average suburban backyard. However, the potential risk is perceived as being greater due to the ideal breeding conditions which would be presented by large volumes of neglected, stagnant tank water in the community.

Current research being conducted by the Queensland Institute of Medical Research (QIMR) will expand on previous findings regarding the increased threat of mosquito breeding in relation to household water storage practice.  This research will involve up to 10,000 Brisbane houses and is planned to continue until 2012.  In all probability, significant mosquito infestation will be detected in tanks which have not been adequately maintained.

Important points to consider to avoid your rainwater tank turning into a mosquito haven:

• Ensure all tank inlet and overflows are adequately screened (minimum 1mm mesh)

• Tank overflows should be fitted with a flap valve to prevent blockage but still retain mosquito-proofing

• Wet systems must have drainage points, rain heads and flap valves fitted to avoid mosquitoes breeding inside inlet pipes
  

• Avoid water pooling on catchment areas and in gutters

• Microscopic mosquito larvae can enter the tank through screens but can be eliminated by adding a water sanitiser

• First-flush diverters must be emptied after each downpour.  Mosquitoes can breed in pooled water held in blocked diverters.
  

• Regular, routine maintenance ensures system integrity and water quality are consistently monitored

• If in doubt, seek professional advice and assistance.  Call WATER TACTICS on 07 33248774
  

And as if you needed added incentive…

Under the Queensland Public Health Act, tank owners can be fined if mosquitoes are found breeding in rainwater tanks.

rainwater harvesting, tank maintenance, water treatment