Tj, is definitely on to something there. Unfortunately, in your climate, wetlands would suffer just as much evaporation and the water would become too heated to be useful and it wouldn't take long before it was a salt flat.

You could could use wetland plantings around your water to absorb some of the salinity:
https://www.sciencedirect.com/science/article/pii/S0378377415000761

Types that are native to your area, since CA has strict regs for "invasive species":
https://www.calflora.org/cgi-bin/species_query.cgi?where-taxon=Phragmites+australis