Hiking the Kahuwaiʻiki Falls Trail on Oʻahu, Hawaiʻi
Distance: 2.0 miles / 3.2 km
The Kahuwaiʻiki Falls Trail in Mānoa Valley on Oʻahu is a short but challenging day hike off the popular Mānoa Falls Trail to one of the six different waterfalls that line the back of Mānoa Valley!
That said, the roundtrip distance is a bad indicator of the trail’s difficulty, and I say this to suggest that hiking to Kahuwaiʻiki Falls is more challenging than a 2.0-mile (3.2 km) hike might lead you to believe.
This is because 0.6 miles (1.0 km) of the one-way distance is the Mānoa Falls portion of the trail. After that, the remaining 0.4 miles (0.6 km) is where the Kahuwaiʻiki Falls Trail becomes challenging, as it traverses a rugged, overgrown, unmaintained gulch with tons of fallen trees and boulders to navigate.
It is because of this final 0.4-mile (0.6 km) stretch that Kahuwaiʻiki Falls is the most challenging of the six waterfalls in the back of Mānoa Valley!
For context, the real order, from least to most difficult, is ʻAihualama, Mānoa, Waiakeakua, Luaʻalaea, Naniuapō, and Kahuwaiʻiki.
This is all to say that the Kahuwaiʻiki Falls Trail should only be attempted by experienced Oʻahu hikers, as the remote, slow, muddy, and tedious adventure up Kahuwaiʻiki Stream is not at all reflective of the easy Mānoa Falls Trail used to get there.
Kahuwaiʻiki Falls Trailhead Parking
Parking for the Kahuwaiʻiki Falls Trail is located at the Mānoa Falls Trailhead at the very end of Mānoa Road in a small parking lot just prior to the trailhead.
Before arriving, be aware that there is a small fee to park, and know that parking is illegal along the side of the short road prior to the paid parking area.
Google Maps Directions: Kahuwaiʻiki Falls Trailhead
Hiking the Kahuwaiʻiki Falls Trail
The Kahuwaiʻiki Falls Trail begins on the Mānoa Falls Trail.
Walking to the Trailhead
To get to the start of the Mānoa Falls Trail, hikers must walk about 0.1 miles (0.2 km) up the road toward the Lyon Arboretum and the ʻAihualama Falls Trail.
To skip ahead to the Mānoa Falls Trailhead, click here.
At this first split in the road, go right to continue up to the Mānoa Falls Trailhead.
What is the Lyon Arboretum & ʻAihualama Falls?
Just steps before the Mānoa Falls Trailhead, Mānoa Road passes the entrance to Lyon Arboretum on the left-hand side.
That said, the Harold L. Lyon Arboretum is a jointly managed arboretum by both the State of Hawaiʻi and the University of Hawaiʻi at Mānoa, located just minutes down the road from the Mānoa Falls Trail.
The arboretum itself is a beautiful collection of tropical plants from around the world, but what makes it so special in Hawaiʻi is that it is one of the most important places when it comes to growing and propagating some of Hawaiʻi’s rarest and endemic plant species—many of which would otherwise be extinct if it wasn’t for Lyon Arboretum and a few others scattered throughout the islands.
All of this is to say, visitors are welcome at Lyon Arboretum, and advanced reservations are no longer required.
To learn more about visiting Lyon Arboretum and the trail to ʻAihualama Falls, I recommend reading all the details in my separate article linked below.
Read My Separate Post: ʻAihualama Falls Trail (Lyon Arboretum)
Mānoa Falls Trailhead
This is where the Mānoa Falls Trail begins at the very end of Mānoa Road.
That said, the 2.0-mile (3.2 km) roundtrip distance posted above begins here, not at the parking area down the road.
To skip ahead to the start of the Kahuwaiʻiki Falls Trail, click here.
Once past the trailhead, the Mānoa Falls Trail begins on a fairly flat path that continues for most of the hike to the Kahuwaiʻiki Falls junction, about 0.6 miles (1.0 km) away.
Hau is one of the very few native Hawaiian plants on the Mānoa Falls Trail, and it’s one of seven Hibiscus species that are native to Hawaiʻi!
This unique container bridge is a 'more recent' replacement of an old, deteriorating bridge, following a multi-year project that began in 2019 to essentially reconstruct the hike to Mānoa Falls, giving us the trail we have today.
I write all this because, prior to the 2021 reopening of the Mānoa Falls Trail, the hike was significantly more challenging to traverse, as it was muddier, more slippery, and more eroded.
However, following the reconstruction, the Mānoa Falls Trail became much easier to hike, as the State of Hawaiʻi took a once very muddy and heavily-trafficked trail and transformed nearly every muddy and eroded section into a hardened, more stable surface to walk on.
Apart from Mānoa Falls itself, this wide-open stretch is one of the most photographed sections of the entire trail!
Mānoa Falls-Luaʻalaea Falls Junction
At about 0.25 miles (0.4 km) into the hike, the Mānoa Falls Trail reaches this small bridge, which is where the Luaʻalaea Falls Trail branches away.
That said, go straight to continue on the much more popular Mānoa Falls Trail, as Kahuwaiʻiki Falls is unlike most of the waterfalls in Mānoa Valley, in that it is not the easiest to connect with the others.
Read My Separate Post: Luaʻalaea Falls Trail
After the Luaʻalaea Falls junction, the Mānoa Falls Trail passes through a handful of Eucalyptus trees, again one of the more photogenic spots on the entire hike.
Following the Eucalyptus trees, the Mānoa Falls Trail simply winds its way through the dense tropical rainforest, gaining elevation gradually, until it reaches the 0.6-mile (1.0 km) mark and the junction for Kahuwaiʻiki Falls.
The big ferns that can be seen growing up in the trees are known as ʻĒkaha ferns, which are native to Hawaiʻi and thrive in the shade of a large overstory canopy.
That said, the overstory canopy does not have to be native for ʻĒkaha ferns to grow, as is the case on the Mānoa Falls Trail, but where the ferns do grow in Hawaiʻi’s native forests, they serve as a good indicator species of an unhealthy native forest because if they start to die off, it generally means something is wrong with the larger trees on which they depend.
I think it’s worth mentioning that a bright, sunny day in the back of Mānoa Valley, such as this, is not the most common.
It’s not that it’s at all uncommon either, but it’s important to keep in mind that Kahuwaiʻiki Falls is a rain-fed waterfall, meaning that it’s not uncommon to hike the entire trail when it’s raining.
To add to this, it’s actually quite impressive how much more rain the back of Mānoa Valley gets compared to both the University of Hawaiʻi and Waikīkī just down the road, which is why I highly recommend coming prepared with a good rain jacket—especially during the wetter winter months.
In addition to a rain jacket, some hikers may want to bring trekking poles for the Mānoa Falls Trail because, while the trail certainly is less muddy following the 2019 reconstruction project, it is much rockier and can be very slippery in spots.
Kahuwaiʻiki Falls-Mānoa Falls Junction
After 0.6 miles (1.0 km), the Kahuwaiʻiki Falls Trail finally branches away the Mānoa Falls Trail at this unmarked junction.
Once at this unmarked junction, go right to begin the short but tedious hike up the unmaintained gulch to the waterfall.
Read My Separate Post: Mānoa Falls Trail
Kahuwaiʻiki Stream
Immediately after leaving the Mānoa Falls Trail, the Kahuwaiʻiki Falls Trail will cross the confluence of both the Waihī (Mānoa) and Kahuwaiʻiki Streams.
This is also a good place to see if Kahuwaiʻiki Falls will be flowing, as the waterfall is rain-fed, meaning that if Kahuwaiʻiki Stream isn’t flowing, the falls up ahead most certainly won’t be flowing either.
At the start of the Kahuwaiʻiki Stream, there is no more trail. This is what makes Kahuwaiʻiki Falls the hardest waterfall in Mānoa Valley to hike to, as the only way there is to simply navigate your way up the rugged gulch through all the previous storm debris.
Additionally, at the confluence, you can follow the ridge between the Waihī and Kahuwaiʻiki Streams for a little bit to save some time, but you need to know when to head back down into the stream before hiking too high.
This side trail up the ridge is only good for about 0.1 miles (0.2 km), so it’s probably easier to use it on the way out than in.
Warning
Other than Kahuwaiʻiki having no trail, the gulch also poses the highest flash flood risk of any waterfall in Mānoa Valley, as there is essentially nowhere to escape a flash flood because of the steep canyon walls and all the storm debris that would limit your ability to hike fast.
You will likely find that it’s easier to hike up on one side of the stream over another, but make sure that you’re always following the water.
On the left side of Kahuwaiʻiki, there is a small fork in the stream that could be easy to follow if you’re not paying attention.
I have to imagine that it doesn’t go very far, but it’s typically dry when Kahuwaiʻiki should be flowing.
Kahuwaiʻiki Falls
This beautiful, long cascade is Kahuwaiʻiki Falls, and it’s the end of the short hike off the Mānoa Falls Trail.
If you’re interested in hiking to more of the waterfalls in the back of Mānoa Valley, I previously mentioned that Kahuwaiʻiki Falls is the least accessible in terms of reaching other gulches across the valley, because it requires hiking all the way back to the Luaʻalaea Falls junction to continue east, or at the very least, knowing where the hidden connection to ʻAihualama Falls is to continue west.
Either way, Kahuwaiʻiki Falls is, in the truest sense, a remote gulch, which is why it feels so isolated from the others in Mānoa Valley.
Native Plants on the Kahuwaiʻiki Falls Trail
The Kahuwaiʻiki Falls Trail is a very low-elevation trail by Hawaiʻi standards, meaning that it is predominantly covered with non-native, invasive species.
However, there are a few native plants to look out for on the hike to Kahuwaiʻiki Falls, including ʻĒkaha, Hau, and Māmaki, scattered along different points of the trail.
If you are curious about trying the native Hawaiian Māmaki tea, I kindly ask that you don’t harvest Māmaki from our native forests but, instead, buy from one of the local reputable vendors, such as those listed below.
If you would like to learn more about these and many other native Hawaiian plants from across the islands, I encourage you to check out my separate post linked below.
Read My Separate Post: Native Hawaiian Plant Guide
