If the word Oroville seems familiar and you’re not remotely familiar with California, there’s a reason for that. First, the tallest earthen dam in the nation at 880 feet is the Oroville Dam that created Lake Oroville in the 1960s, but more interestingly, you’ve heard of Oroville because the town made national news in Feb 2017 after heavy winter rains in the mountains above Lake Oroville, the lake filled up so quickly, they couldn’t release the water fast enough, and water topped over an emergency spillway rushing downhill and taking the hill with it in the process.
If you're curious, just search "
dam failures caught on tape" on YouTube & you can see what this would look like if it had collapsed. It thankfully didn't. The lake level is completely level with the top of the emergency spillway. That's a lot of water.
Officials thought the emergency spillway might collapse sending a 30-ft wall of water into the town of Oroville. A mandatory evacuation order was issued to 188,000 people to get to higher ground immediately, you can imagine how that went trying to fit 188k people onto local two-lane roads at the same time. To get the water out of the lake & release the pressure on the emergency spillway, a concrete spillway was opened and massive amounts of water were released, so much so, the concrete spillway failed and began to disintegrate with massive blocks of concrete being washed away.
At the time, it was a crazy story and quite fascinating to those of us who lived nearby. As soon as the rains stopped, and the water receded, the finger pointing started. But one thing was obvious, the concrete spillway had to fixed as fast as possible just in case the next winter brought the same amount of rain. They did fix it with a gargantuan effort and it cost over $1Billion to rebuild & upgrade the spillway.
Oroville is about 70 miles north of Sacramento as the crow flies. I told the group part of today’s mystery route is we were headed to see the nation’s tallest earthen dam and check out the completed repairs. Plus, the lake is still pretty full from the crazy winter we had a few months back.