What Lives At The Bottom of Jacob’s Well?

Written by Niccoy Walker
Updated: September 8, 2023
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The Grim Reaper stands over the bodies of deceased scuba divers, and the sign reads, “Stop. Prevent your death!” Jacob’s Well is one of the deadliest diving sites in the world, and the placard reminds you that you’re swimming in a watery grave. 

If you were to stare down this seemingly bottomless hole, you might feel existential dread of the horrors below. Unfortunately, that doesn’t stop people from jumping into it. What makes this cave system so dangerous, and what lives at the bottom of Jacob’s Well?

What is Jacob’s Well?

Jacob's Well Texas

Jacob’s Well is an artisan spring and one of the longest caves in Texas.

©Christian Perry/Shutterstock.com

Jacob’s Well is a karstic spring from the bed of Cypress Creek in Wimberley, Texas. It is a 12-foot mouth filled with water that plunges 30 feet before continuing at an angle through 14-stories of an intricate cave system. Its water source comes from the Trinity Aquifer, which spans southwest Texas. The artisan spring once gushed water out of the cave mouth with a flow of 170 gallons per second. Now, it’s a mere ripple and will even cease flowing for some time.

In 1850, European settlers found this magnificent hole with a fountain of water shooting up to 5 feet. The name “Jacob’s Well” is referred to in the bible, and the explorers named it for its religious significance. As its fountain calmed to a light flow, more people began using the spring as a swimming hole. While many preferred to lounge around the mouth and dip their toes in, some were more adventurous. 

Amateurs could get away with diving down several feet, but to get inside the cave takes much more skill and experience. The caves of Jacob’s Well are an unforgiving environment and an extremely challenging 5-hour scuba dive. What makes this dive so dangerous, and what happens if you make a mistake?

Why is Jacob’s Well So Deadly?

cave diving

12 people have died while scuba diving in Jacob’s Well. It is one of the most dangerous diving sites in the world.

©Jellyman Photography/Shutterstock.com

At least 12 people have died trying to dive or swim in Jacob’s Well. Thrill-seekers from all over the country flock to this famous swimming hole to face the challenge of accomplishing one of the deadliest dive sites in the world. Inexperienced divers often tried to get into the cave system, which became such a problem that officials had to put a metal grate 40 feet down into the hole. But why, exactly, is it so dangerous?

The layout and formation of the underwater caves are confusing. The system features false passageways, narrow chambers, and multiple twisty tunnels. It’s easy to become disoriented when navigating through a complex cave. An oxygen tank can only last so long, and if you don’t know where you are and which way you should go, it’s only a matter of time before you can no longer breathe. Experienced cave divers understand how serious a situation can get just from losing your light source. 

Most of the people that perished in these caves did so by trying to enter the third and fourth chambers. The third chamber has a false passage, or a dead-end, that claimed one man’s life when he could not get out. The fourth chamber is pretty much impassable. It’s very narrow and prone to gravel slides, which is how two divers in the late 1970s lost their lives. 

It was so dangerous that rescue was unable to get them out, and one almost lost his life attempting. Officials eventually flushed one of the bodies out in 1981, but they didn’t remove the other until 2000. Many attempts have been made to seal the caves, but determined divers always find their way back inside.

What Lives at the Bottom of Jacob’s Well?

Animals that are blind – Texas blind salamander

Blind Texas salamanders, eel, catfish, perch, and crayfish live at the bottom of Jacob’s Well.

©Matt Jeppson/Shutterstock.com

Catfish, crayfish, eel, perch, and blind salamanders live at the bottom of Jacob’s Well. Closer to the mouth of the spring, you will find turtles, aquatic insects, and crustaceans. People don’t seem to have animal problems in Jacob’s Well, but you may want to steer clear of the Moray eel. They can bite when threatened. These eels are not poisonous, but their bites can lead to infection.

 The only native species that lives deep inside the cave is the blind Texas salamander. Most of the other animals you see will stay closer to the mouth or will only be further down on accident. 

Blind Texas Salamanders

The blind Texas salamander is an unusual-looking creature that adapted to live in underground water, like caves. It is white, can’t see, and features red external gills, which it uses to get oxygen from the water. This strange creature is one of the top predators in Jacob’s Well, and it moves its head from side to side, searching for food at the bottom of caves. 

Its diet typically includes tiny snails, shrimp, and other aquatic invertebrates. This rare species of salamander requires a constant supply of clean water. Pollution and human water usage threaten its safety.

Some More Interesting Facts

  • Jacob’s Well is one of the longest underwater caves in Texas, and it serves as headwaters to the Cypress Creek that runs through Wimberley, Texas. 
  • The deepest point in the entire cave system is 140 feet.
  • The water stays at a near-constant 68° Fahrenheit and maintains excellent visibility. 
  • Local rescue diver put a covering over the hole in an attempt to prevent more fatalities, but adrenaline seekers pulled it off and left a note stating, “You can’t keep us out.”
  • If you were to lose your flashlight in the caves, it would be pitch black. You probably would not know which way was up, down, left, or right. 
  • You can only dive into Jacob’s Well today if you have a special permit from the County stating you are an expert.

The photo featured at the top of this post is © Matt Jeppson/Shutterstock.com

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About the Author

Niccoy is a professional writer for A-Z Animals, and her primary focus is on birds, travel, and interesting facts of all kinds. Niccoy has been writing and researching about travel, nature, wildlife, and business for several years and holds a business degree from Metropolitan State University in Denver. A resident of Florida, Niccoy enjoys hiking, cooking, reading, and spending time at the beach.

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