Well, the mission is now part of a national park, although the Church is still functioning and holds masses, the mill is now only run for demonstrations. The water used to come from a series of canals and aqueducts built by the indians, but in the 1950s, the Corps of Engineers changed the river so that the system didn't work any more.
There were still a lot of Hispanic people who had used the irrigation water for their crops for hundreds of years, and threatened to sue. The Corps lawyers laughed, and pointed out that federal law gave them complete jurisdiction.
Then the lawyers for the farmers explained the intricacies of the Spanish land and water grants, and the details of the Treaty of Annexation with Texas, and the Corps lawyers stopped laughing.
Cost them a bundle.