Tom Howarth is a Newsweek reporter based in Bristol, U.K. His focus is reporting on nature and science. He covers climate change, biodiversity, extreme weather, zoonotic diseases and more.

Map of at-risk watersheds in the US Western ... its secondary impacts to the water supply could affect thousands. These watersheds can carry harmful burn materials hundreds of miles downstream ...

Though unseen, groundwater is also an important source of the water supply. Aquifers ... This gorgeous map from Anna Riling of Four Corners Mapping shows the vast Navajo Aquifer in northeastern ...