First Published September 5, 2017
Updated May 20, 2020
Will it be easy? Nope. Worth it? Absolutely.
–Unknown
This blog is to point out the large number of Albizia trees located in the lush valley of Mānoa, a district in Honolulu, Hawaii, home of The University of Hawaii at Mānoa.
The presence of the Albizia trees in Mānoa is the root cause of the dredging in the Ala Wai Canal.
“Why do Albizia trees matter?” you may ask. Albizia trees plus the cumulative effects of decades of “over-development” cause emergency-level flooding in the Ala Wai Watershed. Compared with other valleys, such as Pālolo Valley, which have little or no Albizia trees, the presence of the Albizia trees in Mānoa affects the conditions downstream, and is the root cause of the dredging in the Ala Wai Canal. The subsequent undesirable environmental conditions make it impossible to make significant progress with beautification in the Ala Wai Canal, and, ultimately, Waikiki.
I will tell you the methodology in how I identified the Albizia trees, and the site conditions, and how they make it challenging to identify Albizia trees. Then, pictures and videos below show what I saw of the trees and their subsequent effects.
What to Look For!
In some pictures below, some Albizia trees are circled in red. Also, other images that do not show mainly Albizia trees serve as reference points. Otherwise, everything green in the pictures, without things circled and without reference points, looks like a harmless mass, furthest from the truth, as the Albizia trees among the mass of green, are the biggest threat to Waikiki, which lies downstream of the greenery.
To make the most of your trip to view and identify Albizia trees in Mānoa, do not let the sensual effects of the sun, wind, and rain, that you see and feel distract you from your mission. Instead, you need to focus on the shape, dimensions, and texture of the Albizia trees! Therefore, when viewed as a group, the crowns of the trees look “feathery” in texture and “flat” in shape. So here are my experiences when I made on-site visits and did field research about Albizia trees and their effects.
The Site Conditions!
Starting at 6 a.m. on July 25, 2017, I traveled on foot and took pictures, so I show here the photos I took in chronological order.
The central location of the picture taking was Mānoa Valley District Park or the grassy area around Mānoa Valley’s public swimming pool, both have expansive views of Mānoa Valley, and for our purposes here, expansive views of the Albizia trees.
To get a good count of the number of Albizia trees by visual inspection is challenging, perhaps impossible, because even though Albizia trees tower over neighboring trees, the entire Mānoa valley, would appear to be a big verdant expanse! Because the crowns of Albizia trees are composed of a multitude of branches, it is hard to see where one Albizia tree begins and where another Albizia tree or other tree, ends. Furthermore, there are Albizia trees that grow right next to each other, while other times, there is a lone Albizia tree surrounded by non-Albizia trees.
While on foot, the weather was a rainforest or wetland type weather, alternating between drizzles and just rain, typical of that valley. Under an open umbrella, I stopped numerous times to seek more overhead shelter and wait for the rain to subside. Also, there was the variation of light to heavy wind-driven rain, typical of the valleys of Hawaii. So even though I was wearing canoe slippers, which is suitable to wear in hot and wet weather, my feet were still uncomfortable.
Also, there is Mānoa Valley’s version of morning rush hour traffic, and since I went on foot, I had to avoid the splashes of approaching automobiles. By 8:30 a.m. however, the clouds cleared up and the sun came out.
Thus, it is rather difficult to focus on identifying Albizia trees due to automobiles, the sheer amount of greenery to view, and the ever-changing weather. Now let us start the tour!
The Tour to Spot Albizia Trees!
I start at Mānoa Valley Swimming Pool, pass by the below locations, and return to the same area. Here are the following places I walk to in this order:
- Mānoa Elementary School
- Mānoa Valley District Park
- Mānoa Stream
- Mānoa Gardens Elderly Housing
- Mānoa Community Gardens
The above locations, in contrast to the mass of greenery, are used as reference points, so again, we embark on this tour to focus on the Albizia trees and their effects.
Outside of Mānoa Valley Swimming Pool








Mānoa Elementary School













Mānoa Valley District Park at 8:30 a.m.
It stops raining and the sun is coming out.






Now we enter an area for dogs, which is on the Southeast side of Mānoa Valley District Park and alongside Mānoa Stream.
“Mānoa Gardens Elderly Housing”
Now we are at 2801 Kahaloa Drive, which is highly vulnerable to flooding!
Here we are at the southeast border of “Mānoa Gardens.” which is alongside Mānoa Stream.
Mānoa Community Gardens
Back at Mānoa Elementary School
On the Northwest boundary of Mānoa Elementary School, along Olopua Street.
Above, At Olopua Street and Mānoa Road looking North
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Below, The same view above zoomed in.



Click here to see the effects of the Albizia trees downstream at the intersection of Pālolo Stream and Mānoa Stream. Hopefully, by now, you will have better understood the problem with the Albizia trees in Mānoa. Please browse or read further!
Related Links:
Frequently Asked Questions on the Ala Wai Problem
Ho’okuleana Design ©2016, 2017
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A Chinese American, Emy Louie (雷慧妮) was born in Hong Kong and raised in Honolulu, Hawai’i. She graduated from the University of Hawai’i at Mānoa in 1991 and earned a degree in Architecture.
In 1993, Ms. Louie relocated to the mainland United States and from 2007 to 2012, she hosted her radio show to interview the movers and shakers of sustainable design and green building and taught continuing education classes to design professionals.
She is president of Emy Louie, Consulting Services, which works on design, conservation, and environmental projects. Since 2018, Ms. Louie spends her time in Honolulu and Central America to do environmental field research.