WEBVTT - How the Hoover Dam Works, Part II 0:00:00.480 --> 0:00:04.760 Hey, everybody, This is Chuck Hello, New York. Specifically, I'm 0:00:04.800 --> 0:00:08.800 coming out there next week, next Tuesday, to perform as 0:00:08.800 --> 0:00:12.440 a part of UH, the We Knows Parenting podcast. My 0:00:12.480 --> 0:00:16.439 buddies Beth Newell and Pete McNerney. Pete, He's Peter. What 0:00:16.480 --> 0:00:19.919 am I talking about? Uh? They're performing live We Knows 0:00:19.960 --> 0:00:23.440 Parenting for the first time at Little Fields in Brooklyn 0:00:23.840 --> 0:00:27.160 on Tuesday night, and I'm gonna be there. I'm coming 0:00:27.240 --> 0:00:28.880 up for this. I'm gonna take the stage with them. 0:00:28.880 --> 0:00:30.920 I'm gonna talk kids, and it's a good chance to 0:00:31.160 --> 0:00:33.519 uh to say hi. Emily is gonna be there to everyone, 0:00:33.880 --> 0:00:35.720 So come on out if you are in the New 0:00:35.800 --> 0:00:41.239 York area Tuesday. That's this Tuesday at Little Fields in Brooklyn. 0:00:41.960 --> 0:00:44.560 Go to We Knows Parenting dot com and buy tickets 0:00:44.600 --> 0:00:47.000 there and UH, I would love to meet you. So 0:00:47.159 --> 0:00:50.960 come on out and say hello. Welcome to Stuff You 0:00:50.960 --> 0:01:00.480 should know, a production of I Heart Radios How Stuff Works. Hey, 0:01:00.560 --> 0:01:03.840 and welcome to the podcast. I'm Josh Clark, There's Charles w. 0:01:04.160 --> 0:01:06.559 Chuck Brian, there's Jerry over there. And this is part 0:01:06.720 --> 0:01:12.600 due the sequel of Hoover Damn. Let's find out what happens. 0:01:13.040 --> 0:01:16.480 So I think the last thing I said was they 0:01:16.480 --> 0:01:21.280 poured the last bucket of concrete on and the end, 0:01:21.360 --> 0:01:26.759 so let's do listener mail. Okay, I'm getting definitely worth 0:01:26.760 --> 0:01:30.800 the two part um. Okay, Chuck. So they poured the 0:01:30.840 --> 0:01:34.040 last bucket of concrete, they grouded everything off, and all 0:01:34.040 --> 0:01:40.160 of a sudden, you now have one solid sheet of damn, Hoover, damn, 0:01:40.360 --> 0:01:43.440 and um. At the bottom, it's much much wider than 0:01:43.480 --> 0:01:45.800 it is at the top. It's like six plus feet 0:01:45.959 --> 0:01:48.000 at the bottom, that's how wide it is. At the 0:01:48.040 --> 0:01:51.600 top is forty five, which still feels substantial. And indeed 0:01:51.640 --> 0:01:55.320 it's enough to have a two lane highway going over it, 0:01:55.840 --> 0:01:59.760 and for a very long time, for sixty something years, 0:01:59.760 --> 0:02:04.280 I've leave that was how you got um from Arizona 0:02:04.360 --> 0:02:06.920 to Las Vegas. You had to drive over the Hoover 0:02:07.040 --> 0:02:10.040 dam on top of it, which seems just about as 0:02:10.080 --> 0:02:13.079 bone headed as it gets. But I guess they were. 0:02:13.160 --> 0:02:15.560 They were They really wanted the gift shop money from 0:02:15.639 --> 0:02:18.120 everybody they could get their hands on. Yeah, it was 0:02:18.160 --> 0:02:20.280 kind of cool to have been forced to do that, 0:02:20.560 --> 0:02:22.360 because whether you liked it or not, you were gonna 0:02:23.040 --> 0:02:26.680 see an amazing thing. Um. But eventually, like you, like 0:02:26.720 --> 0:02:29.679 you were hinting at, traffic just picked up and picked 0:02:29.760 --> 0:02:31.200 up and they're like, you know what, this isn't great 0:02:31.240 --> 0:02:33.960 to have all these cars um driving over this thing 0:02:34.000 --> 0:02:36.800 every day. So let's build a bridge. You know what 0:02:36.840 --> 0:02:40.000 we'll do. Let's build the longest concrete gravity arch bridge 0:02:40.320 --> 0:02:43.560 on in North America. Which is appropriate because again, if 0:02:43.560 --> 0:02:45.400 you take a gravity arch bridge and lay it on 0:02:45.400 --> 0:02:48.480 its side, you've got basically the Hoover Dam right there. Yeah. 0:02:48.480 --> 0:02:51.639 So it spans over a thousand feet about a thousand 0:02:51.680 --> 0:02:55.000 sixty feet of the Black Canyon, just south of the 0:02:55.000 --> 0:02:58.680 old Route, nine feet above the canyon. Have you been 0:02:58.919 --> 0:03:02.639 to this bridge? Yeah, it's cool, Like I have driven 0:03:03.000 --> 0:03:05.480 over that bridge since I visited the damn itself in 0:03:05.560 --> 0:03:09.120 ninety six. And you get a great view from up there, yes, 0:03:09.440 --> 0:03:13.400 you do. You also get to experience the most terror 0:03:13.480 --> 0:03:17.320 you can possibly experience on a bridge because the railing 0:03:17.440 --> 0:03:21.200 is like less than five ft tall. There's no big barrier, 0:03:21.240 --> 0:03:25.799 there's no nuts, there's no nothing. It's just void right 0:03:25.880 --> 0:03:28.560 on the other side. It's so scary. But yes, the 0:03:28.639 --> 0:03:31.280 view is is unparalleled. I don't think you can walk 0:03:31.280 --> 0:03:35.440 across it, though, can you Yes, you can, Yes, I 0:03:36.000 --> 0:03:38.440 had no idea. Oh yeah, there's a no, there's a 0:03:38.440 --> 0:03:42.240 pedestrian walkway and the railing is less than five ft. 0:03:42.440 --> 0:03:45.120 I didn't notice that. Oh yeah, that's that's why you 0:03:45.160 --> 0:03:48.000 weren't terrified. You you walk across this thing and it 0:03:48.200 --> 0:03:50.920 is so scary. Oh my gosh, it's scary. But it's 0:03:51.000 --> 0:03:55.480 really really amazing, like the most amazing views of Hoover 0:03:55.640 --> 0:03:58.880 dam Um. Prior to the bridge opening. We're all done 0:03:59.200 --> 0:04:02.360 like from about this vantage point by helicopter. Now, any 0:04:02.360 --> 0:04:04.520 smoke can just walk out there, just park and walk 0:04:04.600 --> 0:04:07.760 and and see it yourself, and it's pretty amazing. You 0:04:07.800 --> 0:04:09.480 see all sorts of rainbows. We saw a bunch of 0:04:09.600 --> 0:04:12.120 rainbows while we were there, because the water is flowing 0:04:12.800 --> 0:04:16.400 out of the damn outlets and um, the sun shining 0:04:16.400 --> 0:04:19.280 and there's just rainbows. Like you can't you can't throw 0:04:19.320 --> 0:04:21.680 a rock and not hit a rainbow around there. Well, 0:04:21.920 --> 0:04:24.960 Bob mould would end up writing a great song, uh, 0:04:25.040 --> 0:04:28.279 after being inspired by a visit. There a rainbow connection. No, 0:04:28.600 --> 0:04:32.839 he Bob Moulden remember Sugar sure and Whisker do. Yeah, 0:04:32.920 --> 0:04:35.280 but Sugar was his band in the early nineties. And uh, 0:04:35.440 --> 0:04:37.960 he had a great song called Hoover dam I didn't 0:04:37.960 --> 0:04:43.279 not standing on the edge of the Hoover Damn. That's 0:04:43.320 --> 0:04:48.880 such a good bob mole. So March one, believe it 0:04:48.960 --> 0:04:52.240 or not, they finished this thing under budget two years 0:04:52.279 --> 0:04:56.240 ahead of schedule. Um, yeah, I want to say something 0:04:56.279 --> 0:04:58.760 about that real quick. Remember they called Frank crow the 0:04:58.760 --> 0:05:01.080 the guy who was running was the project manager for 0:05:01.120 --> 0:05:04.760 the whole thing. Crow. They called him hurry up Crow's right. 0:05:07.080 --> 0:05:11.599 So he um made the company eight million dollars. Remember 0:05:11.600 --> 0:05:13.640 how they bid the thing out at just twenty four 0:05:13.720 --> 0:05:18.520 grand over cost. By coming in under budget and that early, 0:05:19.120 --> 0:05:22.200 they saved eight million dollars. So he was he was 0:05:22.279 --> 0:05:28.120 quite the hero for the corporate overlords, old slow money bags. 0:05:28.160 --> 0:05:33.240 Crow right. So finally the moment comes, and I can't 0:05:33.240 --> 0:05:36.200 imagine what this must have been like, but they were 0:05:36.200 --> 0:05:40.200 able to release that Colorado River that had been on hold, 0:05:40.640 --> 0:05:43.279 we'll not on hold, but flowing in a different place 0:05:43.880 --> 0:05:47.600 all those years, back into that original route. And all 0:05:47.600 --> 0:05:51.440 of a sudden you have Lake Mead, the Lake Mead Reservoir. 0:05:51.680 --> 0:05:55.280 It is um a hundred and ten miles stretching a 0:05:55.360 --> 0:05:58.240 hundred and ten miles upstream from the Hoover Dam and 0:05:58.640 --> 0:06:03.600 attracts ten million people a year two water, ski and 0:06:04.040 --> 0:06:07.799 sun and boat and do fun things. Yeah. Because again 0:06:07.800 --> 0:06:18.240 it was the designated as the nation's first national recreation area, recreation, recreation, recreation. Uh, 0:06:18.279 --> 0:06:21.680 it's the biggest reservoir in the world and um, which 0:06:21.720 --> 0:06:25.000 is saying something because there's some gigant or reservoirs out there. Yeah, 0:06:25.000 --> 0:06:28.520 this one is one point to four trillion cubic feet. 0:06:29.320 --> 0:06:31.960 They so there's so much water in their chuck that 0:06:32.000 --> 0:06:37.000 they measure it by acre feet, which is how much 0:06:37.080 --> 0:06:40.479 water it takes to flood an acre a square acre 0:06:40.600 --> 0:06:45.760 of land. And there's something like twenty eight million acre 0:06:45.839 --> 0:06:52.120 feet in in Lake Mead at its capacity. That's a 0:06:52.200 --> 0:06:54.880 lot of flooded acres. As a matter of fact, it's 0:06:54.920 --> 0:06:59.080 like twenty eight million square flooded acres of water right there. 0:06:59.640 --> 0:07:02.440 That's a lot of water. Yeah, And like me decide 0:07:02.480 --> 0:07:05.599 we should probably go over some of them, some of 0:07:05.640 --> 0:07:09.680 the stats for Hoover Damn itself, because it's it's done now. 0:07:10.440 --> 0:07:13.000 It's the um at the time was the tallest damn 0:07:13.040 --> 0:07:16.880 in the world by more than three feet um seven 0:07:17.360 --> 0:07:21.080 six ft from the canyon floor. And now it is 0:07:21.640 --> 0:07:26.160 the second tallest still the second tallest concrete gravity damn 0:07:26.320 --> 0:07:30.200 in the United States, behind the Araville Dam in California, 0:07:30.280 --> 0:07:32.000 which I don't know if you looked at that, but 0:07:32.640 --> 0:07:36.400 it's no Hoover dam Oh is it schlubby? I mean 0:07:36.440 --> 0:07:39.440 it's fine. Looks like a big giant slipping slide. It's 0:07:39.440 --> 0:07:43.120 got this huge ramp. Yeah, it's fun. But again, Bob 0:07:43.160 --> 0:07:46.280 Mule didn't write a song called the Araville Damn. Can 0:07:46.320 --> 0:07:48.960 I hear a little snippet of it? If you have 0:07:49.240 --> 0:07:52.520 no no, no, no no, just just play the first 0:07:52.520 --> 0:07:58.400 one again and I'll do this. Aura Ville's so good 0:08:00.240 --> 0:08:04.240 Today Hoover Dame is still uh second in the country 0:08:04.280 --> 0:08:08.960 in power production and ranks eleventh in the world in 0:08:09.040 --> 0:08:13.480 power production. It's second in the country still for power. Yeah, 0:08:13.560 --> 0:08:16.920 for power production. Wow, that's that's that's crazy and the 0:08:16.960 --> 0:08:21.520 biggest until nine when the Grand Coulee hydro electric Dam 0:08:21.520 --> 0:08:25.000 in the Columbia River in Washington State took it over, right, right, 0:08:25.120 --> 0:08:27.200 But so that there and there's still one and two 0:08:27.240 --> 0:08:30.840 I guess then is the thing that's right. But what's craziest, 0:08:30.840 --> 0:08:35.439 So the hydro electric power from the Hoover Dam generates 0:08:35.480 --> 0:08:41.000 like four billion kilowatt hours annually. Okay, that that must 0:08:41.000 --> 0:08:44.160 be like enough to power the entire US. That's actually 0:08:44.280 --> 0:08:49.000 not the case at all. Um, it's about I believe 0:08:50.640 --> 0:08:55.160 quarter or a five of the annual power consumption of 0:08:55.280 --> 0:08:59.720 just Los Angeles County, just Los Angeles. Um, it's about 0:08:59.760 --> 0:09:03.640 a of it, but so sure, and it is having 0:09:03.679 --> 0:09:06.760 a significant impact. I read that if they stopped producing 0:09:06.800 --> 0:09:11.760 electricity at the Hoover Dam, everyone in California and the 0:09:11.760 --> 0:09:16.520 Southwest power bills would go up by like a month. 0:09:16.880 --> 0:09:20.079 That's pretty substantial. Um, but it's it's still I'm I'm 0:09:20.120 --> 0:09:22.360 I guess I'm saying like I'm surprised it's the number 0:09:22.400 --> 0:09:25.920 two guy on the block. Still. Yeah. They the way 0:09:25.920 --> 0:09:29.600 they distribute it to is, Um, California gets about almost 0:09:29.640 --> 0:09:34.360 fifty of the power. Uh, Nevada, Nevada, they both get, 0:09:36.760 --> 0:09:40.400 and then Arizona gets about close to n Did they 0:09:40.440 --> 0:09:45.240 split that yeah, Nevada, Nevada. Yeah, Yeah, but that's only 0:09:45.320 --> 0:09:49.200 fifty three or fifty seventy three. That's still not I 0:09:49.200 --> 0:09:54.120 wonder where if the rest where the rest goes downstream 0:09:54.640 --> 0:09:57.600 the power? Yeah, well no, always so you're talking about 0:09:57.600 --> 0:10:00.240 the power of the water. The power. Oh, I don't know, 0:10:00.200 --> 0:10:04.320 because I wonder how much of that operates the damn itself. 0:10:05.440 --> 0:10:07.679 Can't be that much. I mean, that's a lot left over. 0:10:08.000 --> 0:10:11.080 I'm not sure. Yeah, I'm not really sure. So, um, 0:10:11.120 --> 0:10:14.240 regardless of where that that phantom electricity goest Chuck, I 0:10:14.240 --> 0:10:20.680 want to talk about another extraordinarily foresightful um part of 0:10:20.720 --> 0:10:23.920 this project. Do you remember when they diverted the river 0:10:24.640 --> 0:10:29.160 in those four tunnels around the damn project site? What 0:10:29.160 --> 0:10:32.679 what are you talking about? Well, let's go back. Well, 0:10:32.760 --> 0:10:35.160 we'll go back and replay the entire episode real quick, 0:10:35.520 --> 0:10:39.040 and they'll be in there somewhere. So, so they diverted 0:10:39.040 --> 0:10:41.800 the river so they could build the dam, and they 0:10:41.880 --> 0:10:45.319 saved those those tunnels. They didn't just like cover them 0:10:45.360 --> 0:10:47.240 up and say forget you, we don't need you anymore. 0:10:47.440 --> 0:10:49.760 They said, no, no, no, we can actually use you 0:10:49.800 --> 0:10:53.280 in the future. So one on each side is now 0:10:53.400 --> 0:10:55.920 called the penn stock. It's a it's they they've been 0:10:56.080 --> 0:11:00.439 um encased in steel and then um narrow rowed from 0:11:00.440 --> 0:11:03.199 fifty ft to thirty ft in diameter, which is still 0:11:03.240 --> 0:11:08.000 pretty substantial, and they use those to send water from 0:11:08.320 --> 0:11:13.200 the lake mead to the power station turbines on either side, 0:11:13.200 --> 0:11:15.840 the Nevada side and the Arizona side, and that's where 0:11:15.840 --> 0:11:19.640 the hydroelectric power is is generated. So they use the 0:11:19.679 --> 0:11:23.480 diversion tunnels to generate the hydroelectric power. Now, yeah, it's 0:11:23.520 --> 0:11:28.000 amazing the water falls into these things. Uh go down 0:11:28.040 --> 0:11:31.719 about five feet into this power station, which, by the way, 0:11:31.760 --> 0:11:33.000 part of the tour is you get to go down 0:11:33.040 --> 0:11:38.679 into the bowels. We miss that, which is kind of neat. Um. Yeah, 0:11:39.240 --> 0:11:41.520 you didn't about the word bowels just turned you off, 0:11:41.559 --> 0:11:45.400 So that's why did um. So it falls about five 0:11:45.760 --> 0:11:48.760 feet into the power station. Uh, it's flowing here at 0:11:48.760 --> 0:11:52.040 about two thousand cubic feet between two and three thousand 0:11:52.120 --> 0:11:56.160 cubic feet per second, And anyone who knows what hydro 0:11:56.200 --> 0:11:59.000 electric power means, all you're doing is using that water 0:11:59.559 --> 0:12:03.240 to spin turbine and connect that to a power generator 0:12:03.320 --> 0:12:07.040 and all of a sudden, Arizona, Nevada, and California are 0:12:07.040 --> 0:12:10.680 getting juice, right, which is pretty ingenious because if you 0:12:10.720 --> 0:12:14.760 think about it, when when that water is flowing from 0:12:14.920 --> 0:12:20.000 Lake me down these um these pen stocks to the turbines, 0:12:20.440 --> 0:12:22.720 they're not using any pumps or anything like that. It's 0:12:22.720 --> 0:12:25.920 all just gravity um sending it over like a six 0:12:26.000 --> 0:12:28.840 hundred feet drop and what did you say? It was 0:12:28.920 --> 0:12:34.280 like two thousand to three thousand cubic feet per second, 0:12:34.600 --> 0:12:37.800 So that chuck is a lot of water. That is 0:12:37.800 --> 0:12:41.800 a tremendous amount of water, so much so that converted 0:12:41.840 --> 0:12:45.640 into big Max per second. You're talking eighty nine thousand, 0:12:45.760 --> 0:12:48.839 three hundred and sixty seven big Max per second if 0:12:48.840 --> 0:12:52.120 you're moving water to two thousand cubic feet per second. 0:12:52.600 --> 0:12:55.040 And that's actually accurate based on the dimensions of big 0:12:55.080 --> 0:12:58.640 MACA did the calculation. That's how many big Max would 0:12:58.640 --> 0:13:01.560 be flying past you in a second if if it 0:13:01.640 --> 0:13:04.000 were big Max instead of water they were sending down 0:13:04.040 --> 0:13:07.400 there the other stat which staggers me and uh, because 0:13:07.400 --> 0:13:11.839 I was thinking, like, there's no way Julia actually figured 0:13:11.840 --> 0:13:15.480 out the horse power of this whole thing, and she 0:13:15.640 --> 0:13:18.880 did well, she found someone who did, and this thing 0:13:19.679 --> 0:13:28.960 can crank out almost three million horsepower combined. I know 0:13:29.040 --> 0:13:30.880 that's a lot of horse power, but I'm just trying 0:13:30.920 --> 0:13:33.560 to like put it in other terms, like how many 0:13:33.800 --> 0:13:38.000 how many trains is that We'll just think about standing uh, 0:13:38.000 --> 0:13:40.480 in the middle of a desert and seeing three million 0:13:40.520 --> 0:13:43.559 horses charging at you. It's a lot of horsepower. That's 0:13:43.679 --> 0:13:47.200 a lot of horses. It is so the way that 0:13:47.240 --> 0:13:52.079 the water gets from Lake Mead down to the turbines, 0:13:52.120 --> 0:13:53.880 I mean, it's all very much control. And the way 0:13:53.880 --> 0:13:55.960 they control it is if you ever go to the 0:13:56.000 --> 0:13:59.440 Hoover Dam, just on the Lake Mead side of the dam, 0:13:59.760 --> 0:14:02.439 there these four towers that rise out of the water, 0:14:02.920 --> 0:14:05.920 and those towers have gates that can be opened and 0:14:06.000 --> 0:14:09.800 closed to let water in. And those are the gates 0:14:09.840 --> 0:14:11.440 that let the water and that send it to the 0:14:11.440 --> 0:14:15.320 pen socks down in into to power the turbines and 0:14:15.360 --> 0:14:18.319 the power stations, apparently to the tune of three million 0:14:18.360 --> 0:14:22.360 horse power. It is amazing. Again, all of this if 0:14:22.360 --> 0:14:23.920 you step back and just kind of look at it 0:14:23.960 --> 0:14:26.320 as a kid, you're like, yeah, put a hole here 0:14:26.560 --> 0:14:28.880 to make the water go there, to make the turbine spin. 0:14:29.560 --> 0:14:32.680 It's really simple in a lot of ways. But the 0:14:32.800 --> 0:14:36.720 amount of ingenuousness it took to actually execute it, that's 0:14:36.760 --> 0:14:41.240 where the chef's kiss lines. All right, let's take a 0:14:41.240 --> 0:14:44.640 break here and uh, we're gonna come back and talk 0:14:44.680 --> 0:15:18.800 about uh spill ways right after this. Alright, chuck. So 0:15:19.560 --> 0:15:23.880 they used two of the four diversion tunnels to feed 0:15:23.920 --> 0:15:28.160 the turbines to generate hydroelectric power that leaves to other ones. 0:15:28.600 --> 0:15:31.280 And I know they didn't just forget about those what 0:15:31.400 --> 0:15:35.400 are they using those four? And this is sort of 0:15:35.440 --> 0:15:39.240 the final component here, because what they had to do was, Um, 0:15:39.280 --> 0:15:41.840 I mean, when this thing is working great, which it 0:15:41.840 --> 0:15:44.480 almost always has, we'll get to that in a second. Um, 0:15:44.560 --> 0:15:47.640 everything's awesome. People are getting power, people are waterskiing on 0:15:47.720 --> 0:15:52.200 Lake Mead. Um, people are getting water, Crops are getting water, 0:15:52.360 --> 0:15:55.720 cows are drinking water. Everybody's happy. But they did have 0:15:55.760 --> 0:15:57.960 to think about the fact that the Colorado River used 0:15:58.000 --> 0:16:00.840 to be quite a bear and may get angry again 0:16:00.880 --> 0:16:04.040 one day, or this thing may fail one day. So 0:16:04.080 --> 0:16:06.640 we need to think about what happens if something does 0:16:06.720 --> 0:16:09.320 go wrong, whether it's a flood or the system breaks 0:16:09.320 --> 0:16:13.440 down or something. So they thought ahead and they they 0:16:13.560 --> 0:16:15.920 set up what we're called spill ways. They can actually 0:16:16.000 --> 0:16:21.400 divert once again, all that water into those two outer tunnels, 0:16:22.240 --> 0:16:24.960 uh that are now referred to as spill ways. But 0:16:25.000 --> 0:16:30.040 this is downstream, right right, so not the upstream tunnels 0:16:30.080 --> 0:16:33.560 that are being used UH for the flibbertyg of its. 0:16:33.880 --> 0:16:36.840 Have you ever seen a fish ladder? Surely you have, Yeah, 0:16:37.400 --> 0:16:41.200 we've I think we've even talked about them on something before. Yeah. 0:16:41.200 --> 0:16:45.040 That's basically like an upstream spill way. Yeah, okay, So 0:16:45.200 --> 0:16:47.280 this is the opposite that's sending it down, and it's 0:16:47.320 --> 0:16:50.480 it's it's the exact same principle and almost the exact 0:16:50.560 --> 0:16:53.600 same design as that little overflow hole that you have 0:16:53.680 --> 0:16:57.760 in your sink. So like you you can't flood your 0:16:57.800 --> 0:17:00.960 bathroom because eventually, if that water or level hits that hole, 0:17:01.000 --> 0:17:03.080 it's just going to go into the hole and down 0:17:03.120 --> 0:17:06.520 the drain. Anyway, this is the exact same thing. So 0:17:06.560 --> 0:17:12.639 they utilize those remaining two um diversion tunnels as the spillways, 0:17:12.880 --> 0:17:15.320 and they didn't lower them at all. Remember they reduced 0:17:15.320 --> 0:17:18.040 the other ones to like thirty ft from fifty ft. 0:17:18.080 --> 0:17:20.800 These are still fifty ft spill ways lined with like 0:17:20.880 --> 0:17:25.080 three ft of concrete. But they follow very similar trajectories 0:17:25.080 --> 0:17:27.480 where you know, the water hits a certain level on 0:17:27.560 --> 0:17:30.360 like a flood or whatever, and it goes through these 0:17:30.359 --> 0:17:33.680 spill ways and then it drops several hundred feet I 0:17:33.800 --> 0:17:36.800 think six hundred feet, which is a lot for a 0:17:36.880 --> 0:17:38.919 lot of water to drop. It starts to pick up 0:17:38.920 --> 0:17:42.680 a pretty pretty high velocity, and then it it all 0:17:42.720 --> 0:17:46.280 spills out of these gates a little further downstream beyond 0:17:46.320 --> 0:17:51.120 the hydroelectric plants, and everybody's saved and happy and nothing. No, 0:17:51.119 --> 0:17:54.439 no waters ever meant to go over the top of 0:17:54.440 --> 0:17:57.479 the Hoover Dam. If that ever happened, that would be 0:17:57.600 --> 0:18:01.440 colossally bad. It's never designed to do that. Um, it 0:18:01.840 --> 0:18:05.000 probably never will do that. Even if humans suddenly just 0:18:05.119 --> 0:18:10.159 vanish overnight, the spillways would probably still work. But um, 0:18:10.200 --> 0:18:12.240 that's what it's designed for. Is designed to just get 0:18:12.320 --> 0:18:16.080 rid of that water and reroute it, basically like they 0:18:16.119 --> 0:18:18.919 rerouted the Colorado River, but this time they're rerouting it 0:18:18.960 --> 0:18:21.399 around the power stations which would be swamped with that 0:18:21.480 --> 0:18:23.840 much water. Yeah, and they don't let it's it's not 0:18:23.880 --> 0:18:25.600 like they were like, all right, if this gets within 0:18:25.640 --> 0:18:28.840 like three or four feet, we're gonna take action. If 0:18:28.880 --> 0:18:31.720 it gets to within they said it at twenty seven feet. 0:18:31.800 --> 0:18:34.840 So if the water rises for any reason to within 0:18:34.960 --> 0:18:38.040 that twenty seven feet to the top of where those 0:18:38.160 --> 0:18:42.359 cards are driving, the spillway gates open up, uh, and 0:18:42.400 --> 0:18:46.159 it diverts that water and the dam uh is not 0:18:46.280 --> 0:18:49.240 able to breach, which like you said, would be catastrophic. 0:18:49.640 --> 0:18:52.360 It let's out a big huray uh. And the good 0:18:52.400 --> 0:18:55.600 news is the system, that outlet system has never failed 0:18:56.200 --> 0:18:59.359 uh and it's only had to be used twice once 0:18:59.400 --> 0:19:03.720 for the test in one and then in nineteen eighty three. 0:19:04.080 --> 0:19:07.560 It was actually a flood that got within that caused 0:19:07.560 --> 0:19:10.280 that river to go up within twenty seven feet and 0:19:10.480 --> 0:19:14.280 they opened up that spillway, which I imagine there was 0:19:14.440 --> 0:19:15.959 I mean, it was probably kind of scary, but they 0:19:16.000 --> 0:19:18.880 were probably some engineers that were pretty excited to get 0:19:18.880 --> 0:19:21.800 to use those spillways finally, Yeah, because they I mean, 0:19:21.920 --> 0:19:23.440 you would have had to have been an old time 0:19:23.520 --> 0:19:25.520 or to have been there for the nineteen forty one 0:19:25.560 --> 0:19:28.880 test by the time three came around. So I'm sure 0:19:28.960 --> 0:19:31.119 all these people wanted to see this because they they 0:19:31.119 --> 0:19:33.920 had never seen it work before, and they also wanted 0:19:33.960 --> 0:19:36.320 to know if it did work. And it definitely worked. 0:19:36.560 --> 0:19:39.480 I mean it was it wasn't a drill like one. 0:19:39.520 --> 0:19:41.400 It was a straight up flood like this is what 0:19:41.440 --> 0:19:43.840 it was designed for, and it worked just fine. Yeah. 0:19:43.920 --> 0:19:47.240 But both times during the test and during that flood, 0:19:47.280 --> 0:19:50.640 those spill ways suffered some some damage. So let's talk 0:19:50.680 --> 0:19:55.120 about the um the failures that have happened over the years. Right. 0:19:55.520 --> 0:19:57.960 So in those those first few years, when everyone was 0:19:58.000 --> 0:20:00.360 still kind of biting their nails a little bit, there 0:20:00.359 --> 0:20:03.199 were there were a couple of problems. Um Air bubbles 0:20:03.240 --> 0:20:07.760 formed in these spill ways and seepage, like water started 0:20:07.800 --> 0:20:10.480 seeping under the base of the dam, which is not 0:20:10.600 --> 0:20:14.240 good at all. No, and those are actually two different things, 0:20:14.280 --> 0:20:18.680 so both we'll start with the the um air bubbles, right. 0:20:19.520 --> 0:20:22.480 So that's that's called cavitation. And when the spill ways 0:20:22.520 --> 0:20:25.720 were used, both in that ninety one test and in 0:20:25.760 --> 0:20:30.360 the actual flood, when that water, that huge, huge amounts 0:20:30.359 --> 0:20:33.840 of water fell, you know, six hundred feet down to 0:20:34.000 --> 0:20:36.879 the elbow of the spill way that led it the 0:20:36.880 --> 0:20:40.760 rest of the way out to the river um when 0:20:40.800 --> 0:20:45.000 it hit, when it impacted. By that time, these things 0:20:45.080 --> 0:20:50.960 called cavitations, a little like bubbles of vapor had formed 0:20:51.119 --> 0:20:54.560 in the water column. And these things were so strong 0:20:54.600 --> 0:20:57.000 that when they collapsed they had enough force that they 0:20:57.000 --> 0:21:00.879 could like shatter concrete. So when this the spill test 0:21:01.240 --> 0:21:02.840 was done, the spell way test, and then when the 0:21:02.840 --> 0:21:04.959 flood was over, and the spell ways were turned off. 0:21:05.000 --> 0:21:08.720 They went and investigated. There were huge chunks of concrete missing. 0:21:08.760 --> 0:21:11.280 The water had just sheared it away like it was nothing. 0:21:11.880 --> 0:21:15.480 And the cavitation is still not really fully understood. It's 0:21:15.880 --> 0:21:20.399 part of like a really um infrequent unusual occurrence like that, 0:21:20.760 --> 0:21:24.080 like water typically doesn't flow that fast on Earth over 0:21:24.280 --> 0:21:26.000 you know, a man made structure, so it's not like 0:21:26.040 --> 0:21:28.600 something we have to worry about. But they figured out 0:21:28.600 --> 0:21:32.560 that if you insert aer raiders or air ducts something 0:21:32.560 --> 0:21:36.560 to insert air into that water to kind of lessen 0:21:36.680 --> 0:21:40.800 the blow kind of pad or pillow the the impact 0:21:40.800 --> 0:21:44.800 of those cavitations collapsing, it can protect concrete. And so 0:21:45.119 --> 0:21:48.080 after one they didn't really know what they were doing 0:21:48.359 --> 0:21:52.399 after somebody had figured out aeration by that time, and 0:21:52.400 --> 0:21:54.640 so they installed them right afterwards. And as far as 0:21:54.640 --> 0:21:57.159 I know, they haven't tested it to see if it works, 0:21:57.200 --> 0:21:59.720 but in other places it's been shown to work, so 0:21:59.760 --> 0:22:02.680 I think gets a pretty safe bat that if those 0:22:02.760 --> 0:22:05.840 overflow spill ways have to be used again, they probably 0:22:05.880 --> 0:22:09.560 won't cavitate because of the aeration that was inserted into 0:22:09.600 --> 0:22:11.960 the spill ways. Now, yeah, well, I actually saw in 0:22:12.040 --> 0:22:14.800 forty one they knew that they could do this with 0:22:14.880 --> 0:22:17.200 air ducks, but the government wouldn't pony up for the money. 0:22:17.480 --> 0:22:20.359 Oh is there right, Yeah, they denied the funds. And 0:22:20.600 --> 0:22:23.720 uh it took until that flood of eighty three when 0:22:23.720 --> 0:22:25.959 it happened again, when the government was like, all right, 0:22:26.040 --> 0:22:30.800 we'll pay for this stuff. Fine, Hoover's ghost came out 0:22:32.920 --> 0:22:36.480 for the don't get involved. It's not the government's job 0:22:36.560 --> 0:22:40.520 to pay for broken concrete. So, um, this seepage was 0:22:40.560 --> 0:22:43.600 the other was the other sort of engineering failure, and 0:22:43.640 --> 0:22:45.359 we should, you know, we need to point out that 0:22:45.400 --> 0:22:48.040 this thing is performed really, really well, Like none of 0:22:48.040 --> 0:22:51.280 these failures broke the damn. You know, that's a really 0:22:51.280 --> 0:22:53.440 good point, and I think it's definitely worth pointing out. 0:22:53.440 --> 0:22:57.359 Like the spill waves those were huge you know where 0:22:57.359 --> 0:22:59.920 where and tear that that probably shouldn't have happened in 0:23:00.040 --> 0:23:03.800 probably won't again. But yeah, the whole system still worked. Yeah. 0:23:03.840 --> 0:23:06.600 So if you have a damn like this, Um, the 0:23:06.600 --> 0:23:11.199 stability of this whole thing relies on keeping all that 0:23:11.240 --> 0:23:14.439 water out. So any seepage under the base of that 0:23:14.520 --> 0:23:18.320 damn is not good. It's gonna cause uplift pressure that's 0:23:18.320 --> 0:23:23.200 gonna shift the whole foundation, and this grout uh basically 0:23:23.320 --> 0:23:26.199 was was failing. Um, a grout curtain is going to 0:23:26.240 --> 0:23:29.240 prevent the seepage. So they were pressure injecting all this 0:23:29.359 --> 0:23:34.560 grout into these holes trying to fill cavities, but it, uh, 0:23:34.640 --> 0:23:38.040 it was not and they were getting some seepage in there. Well, 0:23:38.040 --> 0:23:42.960 they did a really poor job of geological exploration before 0:23:43.040 --> 0:23:45.560 they ever started the project. Yeah, that was the main 0:23:45.600 --> 0:23:49.040 issue there. So, like the same grout that they they 0:23:49.080 --> 0:23:52.679 introduced into those cooling pipes after they were finished building 0:23:52.720 --> 0:23:56.280 the actual damn itself, they were they were introducing that 0:23:56.480 --> 0:24:00.439 into these holes they drilled to kind of fill those cracks, crevices, faults, 0:24:00.480 --> 0:24:03.400 all this stuff that's in the bedrock. Because normally, when 0:24:03.440 --> 0:24:06.840 the Colorado rivers flowing chuck, it's like it's fine, it's 0:24:06.840 --> 0:24:08.800 allowed to keep going and it doesn't try to get 0:24:08.840 --> 0:24:12.040 anywhere aside from the river bed. But when it runs 0:24:12.040 --> 0:24:15.560 into the dam, then it's got issues. The water wants 0:24:15.600 --> 0:24:18.240