When good ideas produce bad outcomes

When rainwater passes over hard surfaces, like roads and parking lots, it accumulates pollutants, which are then washed into nearby waterways. In Baltimore, polluted runoff waters are carried to the Chesapeake Bay, where they have negative impacts on the Bay’s ecosystem.

Like many urban areas, Baltimore has created rain gardens and other water features in order to protect water quality. The idea is to slow down the runoff from rain events, filter out sediments and pollutants, and deliver cleaner water to the Bay.

When well designed and maintained, these water features can be complete, functioning ecosystems with plants, fish, frogs, and other organisms. When not well designed and maintained, they become ideal habitats for mosquitoes.

“It’s these holding areas that can be problematic.”

Dr. Shannon LaDeau, a disease ecologist at the Cary Institute, has been studying mosquito habitats in Baltimore.

“Mosquitoes are tolerant of polluted waters and they don’t require that long to complete their development cycle.  So any water that stands for up to a week is good mosquito habitat.”

This is a situation where good environmental intentions can inadvertently cause a nuisance at best and a public health hazard at worst, because mosquitoes are vectors for diseases like West Nile virus.

If we are going to protect our water supply with these created ecosystems, we must commit to ensuring that they are properly maintained.


Photo: courtesy of northfield.org

Produced in collaboration with WAMC Northeast Public Radio, this podcast originally aired on May 7, 2013. To access a full archive of Earth Wise podcasts, visit: www.earthwiseradio.org.

Cary Institute of Ecosystem Studies | Millbrook, New York 12545 | Tel (845) 677-5343

Privacy Policy Copyright © 2018