The Hawaii Kai Marina Community Association (HKMCA), as a non-profit organization, diligently oversees the routine sampling and testing of water quality at various points within the marina. The most recent water quality report can be found here.
Historically, the Hawaii Kai Marina was originally known as Kuapa Pond, which was once Hawaii's largest fishpond. Kuapa Pond was an embayment separated from Maunalua Bay by a natural barrier beach, used by early Hawaiians to catch fish in shallow inland waterways. Before its transformation into a marina, this area functioned as a vital ecological filter. As a basin, it captured terrigenous sediments carried by runoff, thereby safeguarding the bay and its coral reefs.
On October 22, 1991, the Estate of Bernice Pauahi Bishop (now Kamehameha Schools) officially transferred the waterways and properties of the marina to HKMCA. The Hawaii Kai Marina continues to act as a sediment catch basin for the surrounding watershed. Urban development has introduced a storm drain system that channels runoff directly into the marina, affecting the sedimentation process and necessitating regular maintenance dredging to manage accretion.
The Deed transferring ownership of the Marina to HKMCA contains provisions relevant to water quality and provides some context. It notes in relevant part:
"The Hawaii Kai Marina shall at all times be subject to all drainage and flowage (including any siltation as a result thereof) with respect to the Hawaii Kai area, including all such drainage and flowage (including any siltation as a result thereof) with respect to all unimproved areas and all lots and dwelling units and other improvements now or hereafter developed, redeveloped and constructed in the Hawaii Kai area..."
"The design of the sewerage system of East Honolulu Community Services, Inc. is such that there may be spillage from the Hawaii Kai sewage collection system into the Hawaii Kai Marina due to emergency, malfunction, storm waters entering the system or other causes, and that the Hawaii Kai Marina is, and the Association's interest therein shall be subject to an easement and rights in the nature of an easement for such spillage..."
Thus, HKMCA's ownership of the Hawaii Kai Marina is subject to all drainage and flowage from the surrounding watershed, and to periodic overflow of the sewerage system.
As can be seen in the historical water testing results, tidal flow generally keeps the Marina's waters within acceptable contamination levels; however, there are times, particularly when heavy rains occur, when Marina waters exceed levels suitable for swimming and water recreation. With that in mind, it is best to avoid swimming in Marina waters after rainfall until tidal flow can sufficiently flush the waterways.