Las Vegas is apportioned a tiny 1.8% of water from Lake Mead. However, any water it recycles and pumps back into the lake doesn’t count against the apportionment. So, Vegas recycles all indoor water, including that from toilets, and meticulously saves rain water. The whole system is carefully designed so no pumps are needed. Water flows downhill to treatment plants, into marshland for further cleaning, then back into Lake Mead.

Just to be sure, Vegas now has a third straw in Lake Mead at 860 feet. At 900 feet, no water can flow out. However Vegas will still have water to use. No one thinks it will every get that low. However Vegas is always thinking ahead on water, because it has too.

People who worry about those issues sometimes focus their scorn on Las Vegas, which appears culpable mainly because, of all the cities that draw water from the river, it lies the closest to its banks. But, in actuality, Nevada was so thinly populated when the river was divided up that its allotment is very small—just two per cent of the total—and it actually takes less than that, primarily because Las Vegas has some of most stringent water-conservation regulations in the country.

When the pumping plant for the third straw is completed, Nevada will be the only lower-basin user with the infrastructure required to draw lake water from below the level known as “dead pool”—roughly nine hundred feet above sea level, the elevation of the lowest openings in the four intake towers on the upstream side of Hoover Dam.

However, the entire Colorado River is a single system and needs to be viewed that way, especially since seven states rely on its water.

We may be citizens of a community, and a state, and a country, but we are also citizens of a basin,” [Patricia Mulroy] said. “What happens in Denver matters in L.A. What happens in Phoenix matters in Salt Lake. It’s a web, and if you cut one strand the whole thing begins to unravel. If you think there can be a winner in something like that, you are nuts. Either we all win, or we all lose. And we certainly don’t have time to go to court.”

Water years in California go from Oct 1 – Sep 30. The drought has broken, and spectacularly so. It’s already been one of the wettest years ever. If rainfall in the remaining months is normal, it will be the wettest year on record. Amazingly, more storms are coming, and they will fall in northern California watersheds and the Central Valley. This is great news for California, and for Southwest states, because the more water California has, the less pressure there in on the crucial Colorado River, whose water is shared by seven states and Mexico. Several major reservoirs in California are above their historical capacity now, which is way better than things were last March.

Now that we’re more than 2/3 of the way through California’s wet season, it’s pretty clear that much of the state has experienced its wettest 3-6 month period on record. Virtually every corner of the state is above average to date, though anomalies have been much more impressive in the north. The Northern Sierra watersheds are currently sitting at just above 200% of average precipitation for the season to date–a rather extraordinary statistic. If California receives at least average precipitation for the rest of the season, 2016-2017 would become the state’s wettest Water Year on record.

What is pretty clear, though, is that this year’s extreme wetness on the seasonal scale has pushed parts of California’s aging water infrastructure to the brink.

Water levels are rising so fast at Oroville Dam in California due to storm runoff and snow melt that the spillway, which was badly damaged by recent rains may need to be used again. Water levels are now just 5 feet from when the spillway will need to be used. If they release water slowly it could undermine the already compromised spillway, so water will be released in spurts at high volume.

This sounds ominous.

On Thursday, Butte County Sheriff Kory Honea revealed a new warning and evacuation plan for the county’s residents, many of whom were forced to flee to high ground with only an hour’s notice last month when state officials feared a portion of the reservoir’s emergency spillway was nearing failure.

“Our goal is to give people 12 to 24 hours’ notice” and reduce choke points for fleeing residents, Honea said.

Meanwhile, enormous amounts of debris, 715,000 cubic yards, have been removed below the spillway at a cost of over $4 million a day.

It was the best of times, it was the worst of times. The major amounts of rain and snow this winter will boost water levels in Lake Mead and Lake Powell, and this is good news indeed. However more is definitely needed and these crucial lakes are still historically low.

Plus, because the politics of the Colorado River are always more convoluted that they might seem,  needed water this year could mean less emphasis for negotiating the Drought Contingency Plan which would cut water use in the Lower Basin and plan for shortfalls in the Upper Basin. Long-term, that could be a problem.

For those trying to get the damn deal done, the big snowpack is a setback.

So it’s worth reminding ourselves where we’re at. From the perspective of the last few years, a 4 million acre feet bump is great news. But as the graph above makes clear, we’ll still end up the water year down 20 million acre feet from the start of the 21st century. We’re along way from being out of the hole.

Journalist and blogger John Fleck, author of Water is for Fighting Over: and Other Myths about Water in the West points out in his newsletter that Obama now favors the Sacramento Delta tunnels project (and Trump almost certainly will too.) Yes, it will be hugely expensive. Yes, the Delta may suffer. However the delivery of that water impacts the entire Southwest, yes it does.

Because the more water Southern California gets from Northern California, the less it will need from the Colorado River, water which seven states rely on.

From his email newsletter.

The interconnected nature of the West’s water system means California’s success or failure at dealing with the Sacramento Delta impacts the rest of us. Problems there make it harder for Southern California to make the deal that needs to be made to conserve water on the Colorado River. Non-Californians watch all of this nervously.

There’s a second California water issue that also makes me nervous. I had an op-ed Dec. 23 in the Sacramento Bee about the Salton Sea, arguing that without a solution to the Sea’s problems, it is hard for Southern California to join a Colorado River water conservation deal.