The government-backed project is aimed at preventing flooding in downstream areas but the possible environmental impact on local communities could outweigh the dam's benefits.
More than 400 dams are currently proposed for Central America's rivers, but thanks largely to a feisty indigenous resistance—as well as a non-profit—they are still yet to be built.
Dams have been linked to habitat degradation, worsened biodiversity, and negative changes in river ecology.
Heightening the dam will increase the size of California's largest reservoir, but it could also create problems for local fish and wildlife populations.
The infrastructural failure could release a torrent of water into portions of the city that are already submerged—including downtown.
The last few months have seen heavy rainfall in the Golden State, which could spell trouble for California’s dams.