California uses a dual doctrine, both prior appropriation and riparian. As does Oregon and Washington. Because these states straddle the Cascades/Sierra Nevada, which is the western wet/dry line.
The eastern wet/dry line is the 98th meridian so those states that straddle that line use the dual doctrine(prior appropriation and riparian). TX, OK, KS, etc.
So NM, AZ, NV, UT, CO, etc use the single doctrine prior appropriation.
Those states to the east use the single riparian doctrine, which is descended from English Common law.
On top of all this, in 1908, SCOTUS established the Winters Doctrine, aka Federal and Indian Lands Reserved Water Rights, commonly called Reserved Water Rights. This established that tribes with a treaty right to farm also had a right to water for irrigation, and Reserved water rights trump prior appropriation water rights. To put it another way, First in Time, first in right becomes second in line second in right behind reserved water rights.
Then, towards the end of the 20th century, in a series of decisions, the courts re-interpreted Reserved Water Rights to include a tribes' treaty right to fish as well as flora and fauna. These new Reserved Rights manifest as a minimum flow.
And as a practical example of this, the delta smelt had a reserved water right in the form of a minimum flow, and the delta smelts' reserved water right trumped those farmers' prior appropriation water right.
Anyway, back to Bundy, the court ruled against Bundy's claim of vested rights. And when Bundy himself paid the grazing fees to Clark County rather than BLM, he acknowledged that he had no vested rights. And Bundy and his father paid grazing fees from 1954 to 1992 acknowledging that Bundy had no vested rights.
Indian Water Rights - The Winters Act of 1908 was a judicial decision pertaining only to federal reservations and only assigning superior rights as of the date of the establishment of such reservation on federal land.
http://plainshumanities.unl.edu/encyclopedia/doc/egp.wat.041
Arizona (and Nevada) Indian Wars lasted well into 1890. Dates of establishment of Federal Reservations are after the first-in’s were in, so the first-in’s aren’t second-in’s at all.
Water rights of the signatory states to the Colorado River Compact (and the one 40-year hold-out, Arizona) were upheld and codified in 1922, again in 1928 with the Boulder Canyon Project Act, and finally in 1963 with the Supreme Court decision in Arizona vs California.
English common law - as practiced in Australia and Canada, and later copied in the US in the 19th century, held that “government grants of title override native title where there are inconsistencies between the two.”
http://www.nfsa.gov.au/digitallearning/mabo/tn_28.shtml
I don’t think “new Spain” had much influence in the Nevada/Arizona border area. The Spanish Trail wasn’t a safe route by any means and neither Beale nor Powell documented any rancheros in the area.
The Delta river smelt - What would Darwin do? It’s a transpacific dinosaur that magically reduced in numbers in 1993. Dinosaurs go extinct. Let it die. Raise them in aquariums if you will, and charge a quarter to see them, but call it a day and give the food farmers and ranchers back their water.