When 2023 began with weeks of near-constant rainfall, Contra Costa Mosquito and Vector Control District (District) employees suspected this could be quite a year for mosquito activity. After all, where there is water, there is the risk of mosquitoes and mosquito-borne illness. Once the storms began to slow, District employees began looking for rainwater in both expected and unexpected areas of Contra Costa County.

Those unexpected places grew as the weather warmed and Sierra snow began to melt, adding to the abundant water. Then, with this week's king tides, which measured six inches above the predicted height, there is more water, particularly in coastal areas, than many District employees have ever seen. To assess the extent of the water due to rain, snowmelt, and king tides, the District is turning to new technology to increase the ability to conduct mosquito surveillance in large coastal and marsh areas: drones.