08/28/15 – Kaulunani, Hawai‘i Urban And Community Forestry Program, Installs Demonstration Forested Rain Garden In Kailua

Posted on Aug 28, 2015 in Forestry & Wildlife, News Releases

News Release


For Immediate News Release August 28, 2015


HONOLULU —  The Kaulunani Urban and Community Forestry Program is leading the way for urban forestry practices in Hawai‘i with a new cutting-edge forested rain garden project planned for next month in Kailua, O‘ahu. Kaulunani is a federally funded urban forestry program of the Department of Land and Natural Resources (DLNR) Division of Forestry and Wildlife, and is operated by the non-profit organization Friends of Hawai‘i’s Urban Forest (dba Smart Trees Pacific.) 

Why are rain gardens important? During dry periods, pollutants from cars, and other sources accumulate on paved surfaces and are washed into storm drains when it rains. These pollutants are highly toxic to aquatic ecosystems and human health. 

To be located in Kailua, O‘ahu at the intersection of Hamakua Dr. and Hahani St., the garden will treat runoff from the American Savings Bank parking lot. Pictured are images of the site before the rain garden is installed and an artistic rendering of the site envisioned at five years post-installation.Kaulunani is excited to begin the installation of this urban forestry demonstration project in Kailua. Installation of this rain garden is a multi-step process. First, the ground is prepared through solarization. If you are walking past American Savings Bank in Kailua over the next few weeks (August-September 2015) you might see black plastic covering the ground. Solarization occurs when black plastic holds in heat of the sun and kills off existing grass and weeds without using any chemical herbicides. 

Then, once the turf and weeds are removed, installation begins of underground infrastructure for the rain gardens that lays the groundwork for the garden. The final step is planting more than 700 native trees, shrubs and ground covers. Planting is planned for September 2015. 

In addition Kaulunani will conduct a year-long study to compare the benefits of forested rain gardens versus traditional rain gardens. Three separate rain garden plots will be constructed to allow comparison of different plant/tree compositions. Plot A: Native groundcover mix, shrubs, Kou tree; Plot B: Native groundcover mix, shrubs only; and Plot C: Native groundcover mix, shrubs, Alahe‘e tree. Installing two plots with trees gives a significant advantage by allowing us to compare the effectiveness of two different tree species; and also providing a backup in case one of the trees fails to thrive. 

Kaulunani selected Hamakua Marsh as the target water body for this water quality improvement project because of its natural resource significance. Hamakua Marsh/Kaelepulu stream is listed as an impaired water body. This means that there is a significant problem with pollution from the surrounding residential and commercial areas, mainly from roadways, parking lots and other non-point sources. Additionally, Hamakua Marsh is a Ramsar Convention Wetland of International Importance, which makes it a high priority for restoration.

Trees and vegetation act as the first line of defense for intercepting rain as it falls on paved surfaces. Tree leaves, bark and roots all play a role in the process of improving our watershed health by slowing down and cleaning storm water. If we allow storm water to flow into forested and vegetated areas, Earth’s natural filtration system can do its job to clean polluted water in urban areas. Kaulunani’s goal is to improve specific knowledge about the contributions trees make to facilitate their wider use in storm water management practices.

Project Support:   
Smart Trees Pacific, in collaboration with the Department of Land and Natural Resources Division of Forestry and Wildlife, received one of five nationally competitive grants from the USDA Forest Service for improving water quality in urban areas. The USDA Forest Service provided the initial award, which has been matched by grants from Hawaiian Electric, Community Restoration Partnership Fund at Hawai‘i Community Foundation, Matson Navigation Company, Inc. & Subsidiaries, and Sterling Planet, Inc.  Kaulunani is also grateful for the support from American Saving Bank Kailua and Evolution West Management. Service, LLC in making this project possible. 

Supporting this innovative project is an opportunity to contribute to the health of our community. This project is designed to allow other businesses, organizations and communities interested in helping reduce polluted storm water runoff to duplicate the process. 

Kaulunani also offers a cost-share grant program to support tree planting and education in Hawai‘i as well as a newsletter featuring current events in urban forestry, and Learning at Lunch speaker series. Over the past 20 years Kaulunani has provided $2,677,792 in funding to 376 projects which was matched with $7,080,627 in cash and in-kind contributions. Please visit the webpage to learn more about this project at:https://www.smarttreespacific.org/projects/water-quality. For more information on Kaulunani’s programs and cost-share grants please contact [email protected] 

Images are available on Google at: https://plus.google.com/u/0/101613020396360217549/posts

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Media Contacts: 
Teresa Trueman-Madriaga 
Kaulunani Urban Forestry Program 
Phone: (808) 672-3383 
[email protected]

Deborah Ward 
DLNR Communications specialist 
Phone (808) 587-0320