THE NATURE CONSERVANCY • March 17, 2025
Culverts are human-made structures built to channel water beneath roads, bridges and other infrastructure. They’re necessary wherever roads intersect with waterways. An undersized or ill-placed culvert can easily get clogged or collapse. This leads to flooded and damaged roads. The impact is also severe on wildlife and natural habitat—when water can’t flow under roads naturally, the movement of sediment and nutrients is disrupted, and fish and wildlife struggle to migrate up and down stream to complete their life cycle. In 2006, TNC started working with the Maine Department of Marine Resources and the United States Fish and Wildlife Service to collect data on road-stream crossings. Ultimately, after 13 years, the teams assessed more than 25,000 crossings—over 90% of the total found in Maine. Upgrading undersized culverts is a powerful action that communities and private landowners can take to boost their climate resilience and reduce risks to people and buildings, while simultaneously making profound ecological impacts.