Greening Up For Mosquitoes: A Comparison of Green Stormwater Infrastructure in a Semiarid Region

Excited to share a new paper published on the potential for green stormwater infrastructure as a climate maladaptation in the Journal of American Mosquito Control Association (AMCA) with Heidi Brown, Valerie Madera-Garcia, Anissa Taylor, Nicholas Ramirez, and Irene Ogata!

Schematic of green stormwater infrastructure with generic mosquito life cycle embedded. Green stormwater infrastructures (GSIs) where stormwater pools for longer periods may become a source for mosquito emergence. (Brown et al., 2022)

We engaged a group of interdisciplinary undergraduate and graduate students across the University of Arizona through this project to help assess the potential for green stormwater infrastructure as a climate maladaptation that could potentially encourage the breeding of mosquitos. The good news is that the curb cuts we sampled did not retain water long enough for mosquito breeding. The bad news is that one of the larger basins consistently held water longer than designed and had the Culex quinquefasciatus mosquito larvae, a West Nile virus vector.

We highly recommend that any future green stormwater infrastructure design, construction, and maintenance include vector control experts and considerations to ensure it does not unintentionally become a climate maladaptation.

Funding for this project was provided by NOAA Climate Assessment for the Southwest (CLIMAS) and the CDC Pacific Southwest Regional Center of Excellence in Vector-Borne Diseases (PACVEC).

Abstract

Green stormwater infrastructure provides environmental, economic, and health benefits as a strategy for building resilience against climate change impacts. However, it may inadvertently increase vulnerability due to improper design and construction or lack of maintenance. We engaged city stakeholders and a diverse student group to investigate possible maladaptation. After rain events, student interns collected data at green stormwater infrastructure, identified in partnership with city stakeholders, for both water retention and mosquito larvae, if present. During the sampling period in 2018, 24 rain events occurred, with 28 sites visited 212 times including visits to basins (63%), curb cuts (34%), and a bioswale (2%). The largest basin consistently retained water (mean: 3.3 days, SD: 2.3 days) and was a positive site forĀ Culex quinquefasciatus, a West Nile virus vector. We found that while basins can become mosquito breeding habitat, there was no evidence that curb cuts were collecting and retaining water long enough. As cities turn to green stormwater infrastructure to address climate change impacts of increasing drought, flooding, and extreme heat, these findings can help in the selection of appropriate infrastructure design typologies.

The full paper is online at https://doi.org/10.2987/21-7055