HomeMy WebLinkAboutUS_EPA_News_Notes_Issue_71_Excerpt Do Stormwater Retention Ponds
Contribute to Mosquito Problems?
Issue Number: 71
Chapter Name: Technical Notes
Date: 05/2003
The following is an excerpt from the USEPA Nonpoint Source News and Notes Issue Number 71. The full
document can be found at the USEPA website (http://www.epa.gov/owow/info/NewsNotes/).
Mosquito Control
Discussion of mosquito control in guidance manuals
written to date has been sparse, although that should
not imply that mosquito control is not being
addressed. Properly designed, operated, and
maintained ponds are not conducive to standing water
and as such should not be fertile breeding grounds for
mosquitoes. To help control mosquitoes in their wet
ponds, some localities introduce mosquito predators
such as mosquito fish.
Mosquito breeding potential depends on the depth
and location of the standing water. To prevent
proliferation of mosquitoes in wet ponds, guidance
manuals often contain recommendations for minimum
pool depths and the establishment of habitats that
promote colonization of the facility by mosquito
predators both aquatic and terrestrial (e.g., dragonflies
and mosquito fish). Improperly maintained dry ponds,
however, may contribute to mosquito problems. In
cases where the dry ponds are improperly designed
or maintained and do not drain within 72 hours after a
precipitation event, increased mosquito populations
have been observed.
The Florida Cooperative Extension Service reported in
Mosquitoes Associated with Stormwater Detention/ Retention Areas, one of a series of fact sheets by the
University of Florida's Entomology and Nematology Department (http://edis.ifas.ufl.edu/mg338), that properly
functioning, extended detention wet ponds are not a significant mosquito problem, but that dry pond systems
holding standing water as a result of improper design, construction, or maintenance (or neglect) are a problem. As
a result, Florida requires these dry ponds to be designed to drain within 72 hours to prevent the creation of
mosquito habitat.
Types of Ponds
Wet Ponds (Retention ponds)
Wet ponds are storm water control structures that
provide both retention and treatment of
contaminated storm water runoff. A wet pond
consists of a permanent pool of water into which
stormwater runoff is directed. Runoff from each
rain event is detained and treated in the pond until
it is displaced by runoff from the next storm. By
capturing and retaining runoff during storm events,
wet detention ponds control both storm water
quantity and quality.
Dry Ponds (Detention ponds)
A dry pond is designed to capture and slowly
release runoff water for a period of 72 hours or
less after a precipitation event. Dry ponds do not
treat the storm water and are typically constructed
in areas where flood control is the greatest
concern.