Guidelines for Preventing Biting Insect Problems for New Rural Residential Developments or Subdivisions in the Top End of the NT
Medical Entomology
Centre for Disease Control
Department of Health
Northern Territory Government
Darwin NT
October 1997
Updated August 2014
DEPARTMENT OF HEALTH
Guidelines for preventing mosquito problems for new rural residential 2014 Page 1
Guidelines for Preventing Biting Insect Problems for New Rural Residential
Developments or Subdivisions in the Top End of the NT
1. A contour map showing the Q100 line and/or seepage areas is the minimal requirement for informed comment to planning applications. All permanent and semi-permanent swamps, creeks, lagoons or other wet season inundated areas that are in or adjacent to the development should be shown on the development plans
2. Each block must have a minimum of 1ha above the Q100 or seepage line.
Any septic tank and absorption trench should be sited on the area above the Q100.
3. There should be no residential development with block sizes of less than 2ha within 1.6km of large or uncontrolled areas of mosquito or biting midge breeding, unless specific medical entomology investigations are carried out.
The major potential mosquito breeding areas are seasonally flooded brackish reed swamps or flood plains and relatively large areas of mangroves that are only reached by the highest tides of the year. The major biting midge breeding sites are relatively large areas of dendritic mangroves.
4. Large, shallow brackish swamps or tidal areas and dense forested areas contiguous with these wetlands and their wet season extensions should be excluded from any subdivision.
5. Permanent to semi-permanent fresh water lagoons, billabongs or wetlands that are likely to be, or that are demonstrated significant sources of mosquitoes (including their wet season flood extents), should be excluded from any subdivision unless the water features are contained within one block.
6. Subdivisions with block sizes between 2ha and 10ha, which are within 1.6km of brackish swamps or the significant permanent to semi permanent wetlands listed above, should have a notification requirement that these habitats are significant sources of mosquitoes and could pose significant pest and disease risks. Subdivisions with block sizes between 2ha and 10ha, which are within 1.6km of large areas of dendritic mangroves, should have a notification that these habitats are significant sources of pest biting midges.
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2014
7. Rural landholders of lots of between 2ha and 10ha, within 5km of extensive wetlands including floodplains, coastal marshes and significant lagoons could be subjected to severe mosquito pest problems. Rural landholders within 1.6km of large areas of dendritic mangroves would be subject to severe biting midge problems. These landholders should be made aware that local government or Medical Entomology of the Department of Health will not be responsible for biting insect problems and their control in these areas.
8. There must be no impedance of the natural flow of surface water by site development (e.g. construction of access roads) to prevent the creation of mosquito breeding sites. Access roads may need to be fitted with culverts of sufficient size to prevent upstream flooding for periods that will enable mosquito breeding. The invert of culverts should be level with the upstream invert of the creekline/floodway.
9. Appropriate temporary and permanent erosion and sediment control should be provided where applicable, to prevent the downstream sedimentation of waterways and subsequent increase in mosquito breeding. Best practice advice should be sought from the Department of Land Resource Management.
10. Detention basins should not pond water for periods greater than 5 consecutive days. Detention basins may require a central invert to minimise the potential for shallow ponding. Detention basins should be maintained on an annual basis to remove any silt accumulation.
11. Any artificial depressions (e.g. from extractive industries) within a development with block sizes of less than 10ha, or within 1km of any development boundary, or developments with block sizes less than 2ha, that are capable of holding water for a period greater than 5 consecutive days must be rectified by filling or rendered free draining to prevent the creation of mosquito breeding sites.
12. Storage dams or other constructed water features in developments with block sizes of less than 10ha should be constructed with steep straight sides, have a level bottom and be relatively deep (over 1.8m) to prevent the establishment of marginal semi-aquatic vegetation that will promote mosquito breeding.
13. Drainage reserves or easements should be declared over permanent and semi-permanent freshwater swamps, lagoons, creek lines, or other wet season inundated areas within or adjacent to the development.
14. Drainage easements should be declared between water features that will be connected during the wet season, to prevent the impedance of water along
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Guidelines for preventing mosquito problems for new rural residential 2014 Page 3
natural flow lines within or adjacent to the developments with block sizes less than 2ha.
15. There should be no part of a subdivision below the maximum tide level.
There should be an access easement around the maximum tide level in vulnerable areas to allow for the monitoring of mosquito breeding and to prevent the creation of new mosquito breeding sites.
16. Subdivisions adjacent to wetlands or mangroves that contain significant mosquito or biting midge breeding habitat, must have buffer lots with a minimum size of 2ha surrounding the habitat(s). Buffer lots must be rectangular in shape, with the shortest boundary of the lot adjacent to the wetland/mangroves.
