Originally published at: California's atmospheric rivers | Boing Boing
Originally published at: California's atmospheric rivers | Boing Boing
Unfortunately all that rain is nowhere close to enough to counteract the ongoing (and possibly permanent) drought. Climate change is cruel.
Yeah, I’ve been thinking, “oh a couple more years like this, and the drought will be over,” but I just realized even that might not be true. Despite catastrophic flooding, we still haven’t hit “normal” seasonal rainfall and we might not get any more rain after this next river washes over us. (Since the latest drought started we had years where we got a lot of rain at the start of the season and then… nothing.) Locally we’re perhaps at less than half normal - we got a few days of heavy rain but it’s mostly been days of negligible precipitation, so even with the next week of rain, we could end up adding to the overall water deficit rather than starting to reverse it.
California’s future might be droughts alternating with flooding, but it’s just as likely to be droughts and flooding at the same time.
Since the reservoirs have been drawn down, is all this rain refilling them at all?
I’m just happy to have a storm that’s not made out of fire.
Well… some rain is going into some reservoirs. Locally, the reservoirs are at anywhere from 23% to 103% capacity right now. Mostly less than 50%. (I think the “fuller” reservoir numbers might be misleading, as they’ve dropped the capacity of some reservoirs while they work on their seismic stability. We’ve just spent recent decades hoping there wouldn’t be heavy rainfall and an earthquake, as it would have wiped out a good chunk of a major California metropolitan area…) Statewide, it seems some of the smaller reservoirs are at, or a little above, normal levels, but bigger ones are well below where they usually are.
But the state of the reservoirs is only a small part of the picture (more a symptom of drought conditions, really) - there’s also the groundwater levels (which are incredibly low in some parts of the state) which don’t get refilled very much (or at all) by events like this, water sources like the Colorado river whose sources are outside the state (and not necessarily being impacted by this at all), and most importantly the snowpack that keeps waterways full during dry months (and replenishes groundwater). If the atmospheric rivers don’t translate into snowfall in the mountains, they’re not doing much good. (Luckily it looks like they are.)
But the best case scenario here is not that the drought ends, but that various looming water-shortage catastrophes get pushed slightly further into the future.
So it’s the same problem anywhere drought conditions have prevailed for a while. Heavy rains don’t get absorbed into the over-dry land, but run off too quickly to make it into the aquifers, taking anything not fastened down with them. And that’s what these atmospheric rivers are producing.
Yeah, the rains being heavy isn’t terribly helpful, but the core issue is that on a state-wide level, it’s the (lack of) snow, more than the rain, that drives drought conditions. On a very local level, the rain is totally alleviating drought conditions - nearby ground water is heavily replenished from waterways fed by reservoirs, and even if the reservoirs don’t fill up, the ground won’t be completely dried out in a couple months like it was last year, trees will stop dying and native plants will be able to recover a bit.
That is in fact a definite possibility. We have to have consistent years of decent rainfall and snowpack in the Sierra. And those things are exhausted over the warm months because the snow melts and the reservoirs can only hold so much.
I highly recommend this lengthy (but worth the time) article from a couple years ago:
I first learned about this phenomenon in Kim Stanley Robinson’s Ministry for the Future. In the novel, its outcome does not bode well for L.A.
It constantly amazes me that, for a state with such a short history, so much of our policy is either based on, “Let’s assume that will never happen again,” and “Let’s assume this will never not happen,” especially when it comes to water issues.
I live in a house built before 1862, and as far as I know, it’s never flooded, but I’m not counting on that being the case in the future…
On the plus side, the snowpack in the Sierras is doing well, so far.
Yeah, overall it’s about 225% of normal for this time of year. In the Southern Sierras it’s currently at 267% of normal.
As It Happens interviewed a researcher studying it at Soda Springs, and he’s cautiously happy.
Skip to 10:00:
This intense rainfall, which results in devastating floods in some parts, isn‘t all bad for other parts. A synergy of policy, planning, technological advances, and engineering are building the capacities for local communities and groundwater basin management authorities to capture rainfall and allow it to infiltrate into our underground water sources, which is basically good. Land development laws and practices have progressed over the past 20 years and moved away from simply requiring that rainfall be piped into local creeks and channels and out to the ocean, and instead toward reducing pre-existing runoff flows and directing the rainfall to recharge local aquifers. The nasty first flush of the rainwater that occurs during the beginning of a storm, which collects motor oil and transmission drippings from the roadways, now must be diverted through configurations of vegetation and soil that function to detain and treat these surface pollutants, while the excess flows underground via porous basins. This is the case for any new development or redevelopment throughout California, and elsewhere, of course, but. Rain is especially beneficial here in the Los Angeles area, where we have extensive groundwater resources and aquifer capacity. For instance, the Santa Ana River now has many mechanisms along its course to capture floodwater and put it back into the ground.
That being said, we will not likely ever experience the artesian wells that once sprouted across the valley. Over the years, water tables have been sinking precipitously, the population continues trending upward, and even managed basins are at risk of depletion due to our perpetually sunny, desert-like conditions. As a result, people need to be learning to love life while simply subsisting on fewer gallons of water.
Refiling, yes, but most are still 50+ percent below average. So if this is it for rain for the winter…
It’s human nature. Reactive rather than proactive.
If my house floods, given where we sit geographically in the city, things would have to be truly fucked.
There’s that, but also a tendency to presume the stability of certain conditions based on very little history, purely out of wishful thinking. Making it very difficult to, for instance, reorganize agricultural water use because the system was codified around a completely unwarranted assumption about how much water there was going to be in the future, now demonstrated to be false.