The Northern Virginia Regional Commission (NVRC) is making it easier to share rain data and learn about flood patterns with the launch of the NoVa Flood Map rain gauge platform.
The collaborative platform, launched in March 2025, represents the region’s first synchronized rain gauge network, bringing together near real-time data from multiple localities across Northern Virginia.
The initiative builds upon Alexandria’s public-facing rain gauge portal, which the City launched in 2021 to expand early warning information and better prepare residents for flash flood events. Alexandria’s system takes measurements at gauges positioned across the city’s eight local watersheds.
As other jurisdictions followed Alexandria’s lead with their own rain gauge portals, NVRC recognized an opportunity to create a unified regional approach.
“The NoVa Flood Map helps to integrate data from across Northern Virginia partners and monitors rainfall across locations, tracking storms and water levels across rivers, streams, and lakes,” according to project staff quoted in the latest Flood Action Alexandria newsletter.
This information is described as “critical in preparing for flooding, understanding climate patterns, and managing water resources.”
The platform offers an intuitive user experience, allowing visitors to browse the map and narrow their search by rain gauge locality. Users can hover over selected rain gauges to find detailed information and access previous rainfall logs.
(via Flood Action Alexandria)
Measurements update every five minutes, providing near real-time monitoring capabilities during weather events. Additional information is also available through tiles positioned underneath the map interface.
The development of the NoVa Flood Map was made possible through funding from a Community Flood Preparedness Fund (CFPF) grant and the Regional Greenhouse Gas Initiative (RGGI).
NVRC will maintain the platform for five years, during which time staff are exploring several expansion opportunities. These include growing the rain gauge network with additional monitors, developing more options for dashboard specifications, and creating post-rain event data analysis capabilities.
