BBC: Any moves to modify the Los Angeles River, to return parts of it to a more natural setting or to capture water, need to be implemented with care.
Scientists say the key job of the concrete channel, which has featured in countless films and pop videos, is to protect the city from damaging floods.
And that role is likely to become more challenging if climate change brings heavier rains, they argue.
Alternatives to the river's current brutalism will not be easy to find.
"This is not a simple...