Animal Care & Control
Stormwater Quality Features and Mosquito Breeding
CITY AND COUNTY OF DENVER
DEPARTMENT OF ENVIRONMENTAL HEALTH
Nancy J. Severson, Manager
| From: |
City and County of Denver |
|
Department of Environmental Health |
|
Division of Wastewater Management |
|
Neighborhood Inspection Services |
| | |
| Date: |
May 1, 2004 |
| | |
| Subject: |
Stormwater Quality Features and Mosquito
Breeding |
Dear Sir or Madam:
The City and County of Denver, in our continuing efforts to manage West Nile virus would like to offer the following information about stormwater quality features (SWQF) and mosquito breeding. Many of the developments
require SWQFs such as extended detention ponds, retention ponds, landscape
detention, porous pavement, etc on the property. SWQF’s help protect water quality by slowing down and cleansing some harmful constituents from stormwater before it reaches
our rivers, lakes, and streams. Because of their water quality benefits, they are often required elements of stormwater discharge permits. However, some SWQFs can be a problem when
they hold water long enough to allow mosquito breeding. Mosquitoes have always been a nuisance
problem, but in the wake of last year’s West Nile Virus epidemic, it is imperative that we ensure mosquitoes not breed in SWQFs or other standing water.
In most cases mosquitoes can effectively be controlled in SWQF by eliminating
standing water with proper maintenance or where this is not possible, by
regularly treating the feature with a larvicide to prevent the emergence of
adult mosquitoes. SWQF must be checked and treated as needed during the
mosquito season, which is from May through September in our area. Also, check
the schedule and pattern of irrigation for landscaped areas that drain into
your stormwater quality features. Make adjustments to correct the problem if
over-irrigation or the schedule or pattern of irrigation is causing water to
pool in the feature. Review the requirements for operation and maintenance of
the SWQFs as outlined in the Urban Storm Drainage Criteria Manual, Volume 3.
Assign and train staff to operate and maintain the features as specified.
Remember, The City and County of Denver’s Revised
Municipal Code states:
“Any lot or piece of ground within the city on which
there is a pond or pool of unwholesome, impure or offensive water or other
material shall be deemed a health nuisance” (DRMC Chapter 37, Article I, Sec. 37-12).
The following is a list of websites with information on maintaining SWQFs, mosquito larvae control, protecting you from
mosquito bites, and West Nile Virus.
The City and County of Denver would like to
thank-you in advance for your help in this matter. If you have additional
questions, you may contact the following people:
| Questions about water quality features |
Kevin Lewis |
303-446-3658 |
| Questions about mosquitoes or West Nile Virus |
Diane Milholin |
303-698-4964 |
|
Questions about Health Nuisance code enforcement |
Janet Burgesser |
720-865-5457 |
Online Resources
Recommendations for maintaining Water Quality Features:
EPA larvicides for mosquito control:
Sampling for mosquito larvae:
Purchasing mosquito dippers:
Equipment may be purchased from a number of suppliers; some of the online suppliers are
listed for your convenience.
EPA Re-registration of the insect repellent DEET:
West Nile Virus Information:
Revised Municipal Code:
|