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For Immediate Release
September 13, 2018

Board of Water Supply Continues Pumping at Nuuanu Dam #1

No Danger to Community as BWS Takes Proactive Role Managing Dam Level

HONOLULU – The Board of Water Supply (BWS) is continuing to pump at Nu‘uanu Dam #1 in order to reduce the water level due to overnight rains from the remnants of Tropical Storm Olivia.

“BWS has been monitoring and siphoning the excess water from the reservoir since the beginning of the week to keep the water level below the spillway,” said Ernest Lau, Manager and Chief Engineer of BWS. “This is our standard practice prior to and during any major rain event. However, with the heavy rain Wednesday night, we proactively decided to add pumps to the siphons to more effectively lower the water level. We want to stress that the community was in no danger, but we felt it was important to communicate to our residents and businesses due to the increased activity in the area.”

“I would like to thank the management at the Board of Water Supply for proactively reducing the water level at Nu’uanu Reservoir No. 1 after the remnants Tropical Storm Olivia caused a rise of four feet in just a few hours,” added Acting Mayor Roy K. Amemiya Jr. “I’d also like to stress that at no time today were any of our residents downstream of the dam in any danger. We’ll continue to monitor water levels in our reservoirs during heavy rain events, and take appropriate action in the form of pumping and/or siphoning when necessary.”

BWS with the assistance of the Honolulu Fire Department (HFD) will continue to pump water from the reservoir until the level is significantly below the current level. This will most likely mean pumping well into the evening and possibly overnight.

BWS is very appreciative for the assistance of HFD, the Department of Emergency Management (DEM), the Mayor’s Office and Managing Director Amemiya, as well as other city agencies during this event.

An earlier press conference is on the BWS Facebook page and Mayor Caldwell’s Facebook page. The conference features comments from Managing Director Roy Amemiya, who is serving as acting mayor while Mayor Caldwell is away on businesss, Manager and Chief Engineer of BWS, Ernest Lau, and Deputy Director of DEM, Hiro Toiya.

For questions or more information, please contact Kathleen Pahinui at 748-5319 or 292-4672.

nuuanu dam evacuation map september 13 2018

A photo is attached for your consideration and use. The photo is courtesy of the Board of Water Supply.

About the Board of Water Supply

The Board of Water Supply (BWS), a semi-autonomous agency of the City and County of Honolulu, manages Oahu’s municipal water resources and distribution system.  As the largest water utility in the State, the BWS serves approximately one million customers on Oahu.  The BWS embraces its mission of “Water for Life – Ka Wai Ola” – to provide a safe, dependable, and affordable water supply, now and into the future.  Uwē  ka lani, ola ka honua – “When the heavens weep, the earth lives.”  For more information, visit



Kathleen Elliott-Pahinui
Information Officer
Honolulu Board of Water Supply
Phone: (808) 748-5319