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Grady Hillhouse

practical.engineering

Entertaining, educational engineering projects and topics by Grady Hillhouse.

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Science & Space 27Tech Industry & Business 2

1

How French Drains Work

[Note that this article is a transcript of the video embedded above.] In February of 2017, one of the largest spillways in the world, the one at Oroville Dam in northern California, was severely damaged during releases from heavy rain. You might remember this. I made a video about it, and then ano

2

Why is desalination so difficult?

[Note that this article is a transcript of the video embedded above.] This is the Carlsbad Desalination Plant outside of San Diego, California. It produces roughly ten percent of the area’s fresh water, around 50 million gallons or 23,000 cubic meters per day. Unlike most treatment plants that cle

3

The Engineering of Landfills

[Note that this article is a transcript of the video embedded above.] This is the Puente Hills Landfill outside of Los Angeles, California. The first truckload of trash was dumped here in 1957, and the trucks just kept coming. For more than five decades, if you threw something away in LA County, t

4

Is the world really running out of sand?

[Note that this article is a transcript of the video embedded above.] If you have to know the answer right away, it’s no; or at least, my goal with this video is to convince you that the world is not running out of sand. But if it were that simple, I wouldn’t be here (right?) and you probably woul

5

The hidden engineering of runways

[Note that this article is a transcript of the video embedded above.] September 2025 was an unusually bad month for runway overruns in the US. On the night of September 24th, an Embraer 145 with 53 people on board landed long at the Roanoke-Blacksburg Regional Airport in Virginia, overshooting the

6

The Los Angeles Aqueduct Is Wild

[Note that this article is a transcript of the video embedded above.] On the northern edge of Los Angeles, fresh water spills down two stark concrete chutes perched on the foothills of the San Gabriel Mountains, a place simply called The Cascades. It’s a deceptively simple-looking finish line: the

7

Why Bridges Don't Sink

[Note that this article is a transcript of the video embedded above.] The essence of a bridge is not just that it goes over something, but that there’s clear space underneath for a river, railway, or road. Maybe this is already obvious to you, but bridges present a unique structural challenge. In

8

What really happened at the Millennium Tower?

[Note that this article is a transcript of the video embedded above.] The Millennium Tower is the tallest residential building in San Francisco, with 58 stories above the ground and 419 luxury condominium units. The tower opened to residents in 2009, but even before construction was finished, engi

9

What happens when a reservoir goes dry

[Note that this article is a transcript of the video embedded above.] In June of 2022, the level in Lake Mead, the largest water reservoir in the United States formed by the Hoover Dam, reached yet another all-time low of 175 feet or 53 meters below full, a level that hasn’t been seen since the la

12

So you want to build a tunnel

[Note that this article is a transcript of the video embedded above.] It seems like homemade tunnels are kind of having a moment. Just about everywhere I look, it feels like someone is carving new spaces from the ground and documenting the process online. Colin Furze might be the quintessential ex

15

When Abandoned Mines Collapse

[Note that this article is a transcript of the video embedded above.] In December of 2024, a huge sinkhole opened up on I-80 near Wharton, New Jersey, creating massive traffic delays as crews worked to figure out what happened and get it fixed. Since then, it happened again in February 2025 and th

16

The Dangers of Low Head Dams (2019)

Dams serve a wide variety of purposes from hydropower to flood control to storage of water for municipal and industrials uses. But when a dam’s useful purpose fades away, the structure itself still remains. Dams come in all shapes and sizes, but contrary to what you might think, the most dangerous d

17

Myths about construction

[Note that this article is a transcript of the video embedded above.] Construction is something you probably either love or hate, depending on your commute or profession. Obviously, as a civil engineer, it’s something I think a lot about, and over the past 6 years of reading emails and comments fr

19

What is a black start of the power grid?

[Note that this article is a transcript of the video embedded above.] November 1965 saw one of the most widespread power outages in North American history. On the freezing cold evening of the 9th, the grid was operating at maximum capacity as people tried to stay warm when a misconfigured relay tr

20

Why are Texas interchanges so tall?

[Note that this article is a transcript of the video embedded above.] This is the Dallas High Five, one of the tallest highway interchanges in the world. It gets its name from the fact that there are five different levels of roadways crossing each other in this one spot. In some ways, it’s kind of

21

Whatever Happened to Fire Escapes

[Note that this article is a transcript of the video embedded above.] The idea is simple: If there’s a fire in a tall building that blocks the main stairwell, people need an alternative way to evacuate, preferably one that is somewhat protected or at least far away from where the fire is happening

22

What's Under Your Feet in New York City?

[Note that this article is a transcript of the video embedded above.] New York City is unlike any other city in the United States. It’s the most densely populated area in the country by far, absolutely packed with buildings, business, homes, and people. But for all that you can see walking the str

25

Why are smokestacks so tall?

[Note that this article is a transcript of the video embedded above.] “The big black stacks of the Illium Works of the Federal Apparatus Corporation spewed acid fumes and soot over the hundreds of men and women who were lined up before the red-brick employment office.” That’s the first line of one

26

The Hidden Engineering of Niagara Falls

[Note that this article is a transcript of the video embedded above.] Niagara Falls is one of the most spectacular waterfalls in the world. With a vertical drop of more than 50 meters or 164 feet and a flow rate that often exceeds 2800 cubic meters per second or 100,000 cubic feet per second, it’s

28

When Kitty Litter Caused a Nuclear Catastrophe

[Note that this article is a transcript of the video embedded above.] Late in the night of Valentine’s Day 2014, air monitors at an underground nuclear waste repository outside Carlsbad, New Mexico, detected the release of radioactive elements, including americium and plutonium, into the environme

29

How do traffic signals work? (2019)

If you live in a major city, I can take a pretty good guess at one of your most common frustrations: traffic. In city driving, the journey is rarely better than the destination. In most cases, we just want to get where we’re going. Traffic is not just frustrating, but it has consequences to the envi