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Chapter Feature: ESW-KCC's Rain Garden

The ESW Chapter of Kapiolani Community College (KCC) is one of our newest chapters, and is already breaking ground with cool projects.  One of their major projects thus far: the design and implementation of a water delivery system for an on-campus rain garden.

The idea for the project was brought to ESW-KCC by undergraduate biology student Carin Jaber and faculty advisor Wendy Kuntz, an ecology professor at KCC.  The project was initially started as an entry for the Environmental Protection Agency’s (EPA) Campus RainWorks Challenge, in which the EPA asks students nationwide to redesign a portion of their campus to be an “innovative green infrastructure” that “shows how managing stormwater at its source can benefit the campus community and the environment”.  Although a design was not finalized in time for entry into the EPA's 2014 RainWorks Challenge, the rain garden eventually became a reality for KCC’s campus.

The rain garden was designed to address the EPA’s RainWorks Challenge.  Jaber and Kuntz decided to grow only native plants in the garden, which could then be used as a “living laboratory” for biology, botany, and Hawaii studies classes.  In addition, the garden’s location, next to the campus’s `Iliahi Building, was chosen to catch rainwater as it flows down to the lower part of KCC’s campus, which floods when rain is heavy.  Jaber and Koontz enlisted the help of ESW-KCC to design the water delivery system, designating the building modifications that needed to take place.

Rain gardens take advantage of rainfall and stormwater runoff to water their plants, but KCC, located in Honolulu, Hawaii, has sporadic rainfall.  It is common to have one to three days of heavy rainfall, followed by two to three weeks of completely dry weather; in general, annual rainfall is low, about 29 inches per year.  A typical rainwater delivery system would not work for KCC’s rain garden, because the ground would be flooded for a day, and then dry for almost a month.

Under Project Lead Geena Wann-Kung and President Jason Salseg, the system was successfully designed and installed.  To address the sporadic nature of rainfall, ESW-KCC’s system was designed to utilize a few inches of rain and distributes water to the garden over a period of three weeks, effectively stretching out the rain received with minimum storage.  The system uses two 50 gallon storage tanks alongside a vented tube system.  Water collected from the roof goes into the tanks, and orifice tubes in a vented tube determine the water level in the barrel.  Based on the water level, rainwater then flows through orifices into the garden or an external tubing system.  After completing the design phase, the installation process involved collaborating with campus facilities to resolve a few issues; the design of the system involved cutting into the building, and downspouts had to be modified.  Furthermore, ESW-KCC had to ensure an aesthetically pleasing design.

The final phase of the project was funded by Project ‘IKE: Indigenous Knowledge in Engineering, a six-campus University of Hawaii collaboration aimed to increase access to a quality pre-engineering education by focusing on a framework supportive of Native Hawaiian students in engineering fields.  High school ‘IKE students were able to do much of the hands-on planting portion of the project.

As the first project of its kind on KCC’s campus, the rain garden was received well by the community.  It draws lots of attention; students, faculty, and staff walk by it every day, and on Saturdays, a farmers market brings in many tourists and locals.  People are curious to see what it is and what kinds of plants are growing.  The rainwater delivery system’s unconventional design is a point of interest as well.

The rain garden’s future is a promising one, as it will likely be turned into a service learning project for gardening and general maintenance.  This will serve as a learning tool for students and help the students in charge of the garden keep up the maintenance with no cost to the university.  As such, the rain garden definitely has proven itself as an innovative green infrastructure, benefiting the campus community and the environment.


ESW-KCC was among many in making the rain garden a reality.  The project was highly interdisciplinary, involving biologists, botanists, hydrologists, and engineers.  Collaborators include, but are not limited to: facilities adviser Gordan Mann, faculty adviser Dr. Wendy Kuntz, KCC Ecology Club, KCC STEM Program, ESW-KCC, Andy Hood, Prof. Ross, Dr. Aaron Hanai, Prof. Anderson, Alex Lum, Malama Maunalua, O'ahu Resource Conservation and Development Council, and Hui O Ko'olaupoko.