there is no explanation of where the millions of gallons of water per month are going.
The article says "The hotel and conference facility on the property is not operating". They've been building on the site since the late 1800's, the current hotel was built in 1939, and Wikipedia says "In March of 1992, the resort went for sale with no buyers. [...] The resort was vacant till sold to San Manuel in 2017."
How about a leak? The property has over 130 years of buildings being put up, burnt down, and demolished; the current building had 25 years of neglect and isn't even currently being used. How about burst waterpipes? Doesn't even have to be one at the current hotel, could be one from the old resort that everyone's forgotten about. Or could be one under the current hotel that's in the process of making a massive sinkhole. That's my guess.
Regardless, I'm glad of this. The whole private companies making money off of public resources really bothers me.