This is adapted from something i wrote on Facebook today, blog-iffied upon request. I will try to go back to adding the occasional blog post here, if I can.
As of the morning of February 13rd, the immediate risk has lessened as the water has stopped pouring over the emergency ‘spillway’ – which is actually an un-reinforced 30 foot tall concrete dam. Water is being routed down the main spillway, which is also damaged, and there are more storms on the way. And after those, comes the spring melt of the enormous Sierra snowpack. The risk of lots of loss of life has thankfully decreased a lot. But the risk of very bad things hasn’t gone away. The engineers who run the dam have to somehow dump out more water than comes in until they can fix the spillways, which may not even be possible given the amount of time available.
It sounds like the emergency spillway very nearly collapsed. As mentioned above, it includes a ~30 foot tall concrete dam. Some very quick research: Lake Oroville holds about 25 square miles of water. Some of that is under 30 feet deep, but even given that, if this ‘spillway’ gave out, my rough calculation is it would release more water than the entirety of Lake Castaic, a large reservoir in southern California. If that had happened yesterday, before people got out, it would have probably amounted to the worst loss of civilian life in this country due to disaster since the Galveston hurricane of 1900. Or worse. if that came at all close to happening, then some VERY serious questions need to be asked.
California’s water situation is …complicated. Many think the state is all desert or it just never rains. The truth is much more complicated. Most of the state is not desert. However precipitation ranges widely from year to year. The one constant is that it almost all falls in the cold season. Oddly, very dry series of years often occur just before or after single very wet years. During wet years, storms cross an ocean that covers half the globe before hitting the Sierras and Transverse Ranges – 10,000 to 14,000 foot tall walls of granite. The amount of precipitation that falls is mind blowing – storms with over 20 inches of rain in the mountains over a day or two are not unheard of.
California’s Central Valley, home to several large cities and the largest and most productive factory farms perhaps on Earth, is mostly a floodplain. In the 1860s a flood turned it into an inland sea. Now, huge dams protect the valley from most floods and provide water in the summer – though a repeat of the 1860s flood would certainly overwhelm all the dams. Even in smaller floods, dams are not without risk. They can break, and in a geologically active place like the Sierra with high erosion most dams fill with sediment and become useless in 50 to 250 years anyway.
I realize that’the whole valley should have been left natural’ is probably not realistic. But on the other hand, if more space had been left for rivers and wetlands, more water could be released for the dams earlier, reducing risk. If flexible farming like that in the Yolo bypass took up the entire central valley, and people did not build permanent homes in the flood areas, the valley could be allowed to flood, and would replenish aquifers. Instead, the rivers are reduced to gutters and when it does flood the precious water is dumped into the sea. California needs to do a better job protecting its rivers, floodplains and wetlands downstream from its dams to reduce damage from floods. We also need to protect the watersheds upstream to reduce sedimentation and floods entering the dams in the first place.
A lot of weird garbage is flying around the Internet. People or things getting blamed, mostly in error:
-‘Liberals’ and ‘tree huggers’. – aren’t the ones who built dams or built in the flood plains. and ‘tree huggers’ actually warned of this possible disaster a decade ago. So… nope. And for you sick weirdos who take pleasure in ‘liberals’ potentially being drowned in this flood? Butte County went for Trump as did most other parts of the Sacramento Valley. Though it doesn’t really matter. you are a seriously screwed up individual if you wish drowning on people who vote for a different person, even one as awful as Trump.
-‘Trump’ – speaking of which – no, he’s an asshole, but he hasn’t been around long enough to cause this problem. He doesn’t know anything about California dams, nor does he care. Bush, Obama, and Clinton didn’t fix the dangerous emergency spillway situation. And considering Trump’s incompetence, cries to get him involved seem a bad idea to me. He’d probably appoint someone horrifically incompetent to deal with the problem anyway.
-‘The Delta Smelt’ – a poor little fish that is going extinct due to bad land and water management. The punching bag of certain people who want unlimited water to waste on their fields and lawns. If anything trying to save the smelt meant slightly more river left intact and slightly lower flood risk. Anyhow, there’s a good chance it is extinct anyway.
-‘Climate Change’ – it is likely it made this particular flood worse by causing higher snow levels and more precipitation to fall as rain instead of snow. But did not cause the underlying problem. The extreme rains have a historic precedent. There were worse floods in the 1800s. Climate change is a big deal and we need to stop adding to it, but blaming every California drought or flood or tree death on it ignores the other much deeper and more complex problems facing the watersheds and ecology of the state.
-lack of infrastructure maintenance – yeah a legit problem. But who to blame? Happened under the watch of both parties and many others. Apparently people don’t want to properly maintain dams. One could argue this is an example of apathy towards the well-being of rural people, but if the dam broke people in the larger cities would face serious problems later on as well.
-People living in flood plains – not the fault of the people living there, they are just trying to get by and there aren’t many other options. These aren’t wealthy towns. When a whole valley is a flood plain, that is where your farm is, and there aren’t other options, you just do what you do and hope for the best. the whole Central Valley should have been developed very differently but that isn’t the fault of the people who live there now.
-Complete failure of land use planning, conservation, water use, oversight of any of these problems over the last 150 years by both/all parties – yeah I am gonna go with this. Definitely this.
Moving forward, if we are lucky the spillway will not fail, but the dam is also not able to do its intended job in reducing floods. This will cause impacts all the way down to the sea, because the Feather River is huge by California standards, probably the biggest tributary of the sacramento. At least one levee failure in the Delta was apparently already happening. if too many delta levees fail, salt water may intrude into the new ‘bay’ and make the California aqueduct unusable. Which is a Big Deal. So… still a LOT to watch here.
I am hoping we avoid the worse scenarios here. I am also hoping that this event causes a rethinking of water and watershed management in the state, though I am not hopeful.
Sorry this is kind of an unedited and ragged post. I will try to share more as it comes.