Umauma Falls facts for kids

The Umauma Falls are beautiful waterfalls found on the Umauma River. They are located on the Big Island of Hawaii, about 16 miles north of Hilo.

What makes Umauma Falls special is that it's actually a series of three waterfalls very close to each other. You can easily see them from a special viewing spot. This spot is on private property that belongs to a botanical garden. You can visit it for a small fee. The viewing area was built in 1996 by Walter L. Wagner. He wanted it to be part of his World Botanical Gardens tourist attraction. Later, around 2008, the viewing spot became part of a different place called Umauma Experience, which is also a botanical garden.

How Umauma Falls Were Formed

The Umauma Falls and River have been forming for millions of years. This started when the Mauna Kea volcano, where the river flows, slowly rose from the sea. As the volcano grew, it created layers of volcanic ash and hardened lava. These layers erode, or wear away, at different speeds.

Eventually, Mauna Kea reached its current height. Then, it entered a final stage where it mostly had cinder cone eruptions. These eruptions left a thick layer of ash, which is now the rich, fertile soil you see today.

Rain and River Flow

Because of the trade winds, the southern parts of Mauna Kea get more rain than the northern parts. The Umauma River is right on the line between these two areas. The word "Umauma" means 'constantly flowing' in the Hawaiian language. It is the most northern river on the island that flows all year, even during dry seasons.

Sometimes, the rain can be very heavy. Records show that two feet of rain can fall in just a few hours! This makes the rivers swell up and flow very fast. The strong water can even move large rocks and boulders downstream.

The Story of Waterfalls and Pools

As boulders tumble down the river, they hit the ground and cause erosion. This creates small waterfalls. Over time, as more boulders fall over a waterfall, they dig a deep hole at the bottom. This hole is called a plunge pool. When the river flow is low, these plunge pools are great for swimming! Many waterfalls on Mauna Kea have these cool swimming holes.

Eventually, the rock face behind a waterfall can get worn away by the plunge pool. When this happens, the rock can collapse into the pool, filling it with debris. Later, heavy rains wash away this debris, leaving a new, clear plunge pool. But the waterfall itself has moved a few feet upstream! Over long periods, waterfalls slowly move higher up the slope.

Sometimes, a waterfall might hit a very strong rock layer that resists erosion. If this happens, lower waterfalls can "catch up" and merge into one bigger, deeper waterfall. This process is slowly moving Umauma Falls upstream over a very long time. You can still see the plunge pools at the base of all three Umauma Falls. (There are many other waterfalls on the Umauma River, and they are also moving upstream!)

To imagine what Umauma Falls might look like far in the future, you can visit the nearby KoleKole River. It has a very large single waterfall called Akaka Falls. This waterfall formed in the same way, long ago. It is further upstream than Umauma Falls and gets much more rain.

Discovering the Viewing Spot

For a long time, the only way to see Umauma Falls was to walk along the riverbed. But in 1995, the person who started the World Botanical Gardens was exploring the edge of the Umauma River valley. He was looking for a good place to view the falls. He found the current overlook, which had been hidden by many wild guava trees and sugarcane plants.

Soon after, he cleared the area. He removed the overgrown plants and built the current viewing spot. It now has a concrete platform, retaining walls, and a steel railing, just as you see it today.