Catch Basins & Storm Drains

Catch basins and storm drains act together to collect and discharge stormwater and can be important habitats for mosquito larvae, including Culex species such as Culex quinquefasciatus, Cx. pipiens, Cx. restuans and Aedes species such as Aedes aegypti. These species are mosquitoes that can carry arboviruses such as West Nile virus, Dengue and Zika virus. Therefore, storm drains and catch basins should be part of local mosquito control district’s surveillance and control programs.

In residential areas, a drainage system such as a storm drain can be found to hold water throughout the year and can serve as important development sites for mosquito larvae. Catch basins are like storm drains in that they are underground vault-like structures that slow down and hold water before it eventually drains to a larger body of water or wastewater treatment facility.

These types of habitats are identifiable by a grated cover and larvae can be discovered here by surveillance methods such as larval dipping.

Because Public Health, That’s Why

Catch basins and storm drains have been gaining increasing attention as potential larval habitat in recent years. Diseases such as West Nile Virus, St. Louis encephalitis, Dengue and Zika are all major sources of concern regarding public health. Controlling mosquito populations in stormwater structures has become more important than ever, specifically in a location where they are not designed to limit mosquito production. Mosquito species such as Culex nigripalpus and Cx. quinquefasciatus, which are known to transmit WNV to birds and mammals can be found in large numbers in the nutrient-rich water trapped in catch basins and storm drains (Rey et al. 2006).

catch basin and storm drain mosquitoes

The Two Main Types of Basins Used to Manage stormwater:
Dry Detention & Wet Retention Basins

Dry detention basins are designed to hold water during storm events and then release the water within 3 days. Because these systems are designed to hold water for only short periods of time, they are not a suitable habitat for mosquitoes. The larval stages of mosquito species require approximately 7-10 days to emerge into adults.

Wet retention basins are designed to hold permanent pools of water. These systems are usually between 3 and 8 feet in depth. Most mosquitoes only breed in shallow standing water (i.e. less than 3 feet) or deeply vegetated waters so mosquito breeding should not occur. However, catch basins hold standing water and require maintenance to ensure that leaf litter and other debris does not accumulate.

If maintenance of these systems, such as cleaning out sediment or the use of screens to keep debris out, is not done on a regular schedule, mosquito control involving the use of insecticides to kill the larvae may be necessary.

storm drain

Ways to Limit Mosquito Production in Catch Basins & Storm Drains

  1. Ensure structures quickly collect, store and transport runoff away from developed areas to prevent flooding
  2. Minimize contact of runoff with pollutants
  3. Use vegetated areas like swales and rain gardens to slow the velocity of water
  4. Proper inspection and maintenance of catch basins and drains
    1. Remove debris and sediment from inlets, outlets and the bottom of ponds
    2. Eroded areas must be repaired
    3. Bare ground must be seeded to prevent soil loss
    4. Harvest plants as needed
  5. Insecticides to control larvae and adults

How Can Mosquito Control Districts Prevent Mosquito Emergence?

Mosquito control districts can also do their part to limit mosquito larvae in catch basins and storm drains. Surveillance efforts involving field inspections via larval dipping can help to determine when and where insecticide applications are necessary.

If you need help determining which insecticides you need to apply, contact us today to help you determine the right product for the right habitat. In addition, these are three trusted products we recommend:

MetaLarv XRP is a biorational, extended release pouch for pre-hatch and standing water control of mosquito larvae in catch basins and storm drains. It features 4.25% (S)-methoprene and utilizes Valent BioSciences’ proprietary Triple Release Technology™.

MetaLarv XRP

VectoMax WSP is a dust-free, clean to the touch, and easy to apply product that is malleable and slips into tight spaces, while not getting hung up on debris, or enclosed in sediment at the bottom of your catch basins.

VectoMax WSP

Need a more economical treatment for catch basins with many of the benefits of VectoMax WSP (malleable, fits in tight spaces, dust-free, clean to the touch)? Use VectoLex WSP’s for half the cost!

VectoLex WSP

Have Questions? We’re here to help!

ADAPCO, an Azelis company, has technical experts that can help you select the right solution to control problem vectors in your region. We are ready to share our knowledge and experience with you!

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