We Went Tubing Down an Old Irrigation Ditch on Kauaʻi

I had a lot of questions.  

How cold is the water?  

How long is the drive?  

Am I going to freak out in the tunnels?  

Our guide answered all of my questions—“not very,” “not far,” “no worries”—before I hopped in the open-air, four-wheel-drive vehicle with my 6-year-old son to ride inner tubes down an old irrigation ditch.

Tubing down Hanamā‘ulu Ditch is fun for the entire family.
Photo: Courtesy of Kauaʻi Backcountry Adventures

This is one of the tours offered by Kaua‘i Backcountry Adventures, an outfitter based in Līhu‘e that specializes in eco-adventures. (Another popular tour is its seven-line zipline course.)   

The 3-hour tubing adventure starts with a 30-minute drive through an old sugar cane plantation—Līhu‘e Plantation—the land of which is owned by AOL co-founder and Hawai‘i native Steve Case. He purchased 18,600 acres of land here in 2001 for about $25 million. The bulk of the land is zoned for either conservation or agriculture. Case opted to keep and maintain the existing irrigation system left by the sugar company—which is what we are about to flume down.  

We meet at the outfitter’s headquarters in Līhu‘e, a quick 6-minute drive from the airport. It’s a huge, open-air space, with bathrooms, changing rooms and lots of places to sit while you’re waiting.  

This is where we get briefed for the tube ride. The outfitter provides the helmet and gloves you’ll need on the ride. If you didn’t bring water-friendly shoes like Crocs or reef walkers, you can rent them here.  

The guides go over what to expect on the tour, from the bumpy 30-minute drive inland toward Mount Wai‘ale‘ale, one of the wettest spots on the planet, to the lunch we’ll be eating after.  

On the drive our guide explains what we’re seeing, from the expansive undeveloped land that was once a thriving sugar cane plantation to the unique geological landscape around us.  

We’re heading toward Mount Wai‘ale‘ale, a massive shield volcano that looms 5,148 feet above sea level. Often shrouded in clouds, it’s one of the world’s wettest spots, averaging 450 inches of rainfall a year. (By comparison, average yearly rainfall in Honolulu is 23 inches.) Fitting since its name means “overflowing water” in ‘ōlelo Hawai‘i (Hawaiian language). All seven of Kaua‘i’s rivers originate at the summit of Wai‘ale‘ale, including Wailua, the largest navigable river in Hawai‘i at 20 miles long. And erosion from all this water has carved canyons in the mountain’s flanks, most notably Kaua‘i’s Waimea Canyon, nicknamed the Grand Canyon of the Pacific. It stretches 14 miles long, 1 mile wide and more than 3,600 feet deep. Almost everything that lures visitors to Kaua‘i—the island’s magnificent waterfalls, the breathtaking canyon, the river-carved valleys—can be credited to Wai‘ale‘ale.  

And that includes the water in the ditch we’re about to ride. 

The cool water flows down from Mount Wai‘ale‘ale. 
Photo: Courtesy of Kauaʻi Backcountry Adventures

We arrive at the start of the flume, removing our bags, towels and whatever else isn’t going with us in the inner tube. (The outfitter brings our stuff to the lunch site.) The guides help us ease into the tubes, warning that if any of us says the water is cold, they had permission to splash us. (The water wasn’t actually that cold.)  

We are floating in Hanamā‘ulu Ditch, which was dug by hand in 1870. It served as the conduit from Wai‘ale‘ale, carrying water 4 miles down the mountains to the sugar cane fields Līhu‘e Plantation Co., which originated in 1849 to 2000. (When it closed it was owned by Amfac, which also operated Kekaha Sugar Co. About 400 workers lost their jobs.) Today, the irrigation system provides water for cattle ranchers—and Kaua‘i Backcountry has access to sections of it for this exclusive tubing tour.  

The ditch varies in width, wide at first, then narrows to fit just a single tube. I immediately get separated from my son, who, I found out, is happily riding with another family. I take a deep breath and literally go with the flow.  

It feels more like a lazy river at first, a gentle push down the fern-lined open-air ditch. I lean back and take in the trees looming overhead.  

There are five tunnels along the ditch, all dug by hand with pickaxes and shovels, explain our guide. The shorter ones are straight; the longer ones are S-shaped.  

We come to the first tunnel. It’s short, about ¼-mile long. Our guide, who’s at the front of the pack, spins his tube around, pulls out an ‘ukulele and starts playing, “Sunday Morning” by Maroon 5. I have to say, the acoustics in the tunnel are amazing—and  his singing helps me forget I’m floating in a dark tunnel.  

After the second tunnel, you have the option of getting out—it’s called the Ladder of Shame, though there’s no shame in exiting the ride. The constant spinning and bouncing off the ditch walls, coupled with the dark tunnels, isn’t an experience for everyone.  

But if you make it past the second tunnel, you’ll reach the highlight—at least for my son and me—of the ride: a fun (and very gentle) 3-foot water slide. There isn’t a person who’s shooting down the slide that isn’t smiling or laughing.  

The third tunnel is the longest and darkest, and it takes a few minutes to get through it. The headlamps really help since the tunnel is S-shaped and I can’t see the end until the last turn. At least I can see the tunnel walls and the other riders around me. (I have no idea where my son is, but I can hear him laughing behind me.)

Kids as young as 5 can enjoy this unique adventure.
Photo: Courtesy of Kauaʻi Backcountry Adventures

It takes about an hour from the start of the flume to the end, when the ditch opens up and we can get out of our inner tubes and walk or swim. (I opt to stay in my tube and relax.) I find my son, wading in the cool waters with a huge smile on his face.  

“Mom! I found you!”  

“Were you looking for me?”  

“Not really.”  

The guides help us out of the water and we head to a few picnic tables on the bank of the ditch. We make our own sandwiches and load our plates with fresh fruits, chips and cookies. It’s nice to be in the sunshine—and sharing at least this part of the experience with my son.  

I’ve been to Kaua‘i dozens of times and I’ve done a lot of things, from snorkeling off the Nāpali Coast to hiking all over Kōke‘e State Park. This tubing adventure is, hands down, the most unique experience I’ve had so far—and the only one my son keeps asking to do again. 

TIPS  

• You can wear Crocs. They work as protective water footwear. The company rents them out if you don’t have water shoes.  
• Use sunscreen and bug repellent for mosquitoes. Even though much of the ride is shaded, you’ll be eating lunch on outdoor picnic tables.  
• Bring a waterproof pouch for your smartphone for photos. The company does snap photos at three locations on the ride.  
• The water is cool but not cold. You don’t need a wetsuit or rashguard unless you’re using it for sun protection.  
• Leave your sunglasses. You won’t need them because you’re mostly under trees or in tunnels. If you want to bring them, attach a strap or retainer to them.  
• Claustrophobic? Don’t worry. The tunnels are big, so you don’t feel confined. (Our guide played music and sang, and that really helped!) 

$149 per person, ages 5 years and older, 300-pound weight maximum, must be at least 43 inches tall. Cost includes lunch and water. (808) 245-2506, kauaibackcountry.com  

This story was originally published in our Winter 2024 issue. Buy a copy here.