Subterranean streams “flowing through known and definite channels” are regulated by California’s surface water rights system.
The following physical conditions must be present in a subterranean stream flowing in a known and definite channel:
(1) a subsurface channel must be present,
(2) the channel must have relatively impermeable bed and banks,
(3) the course of the channel must be known or capable of being determined by reasonable inference, and
(4) groundwater must be flowing in the channel.