PROJECT NAME: Nu’uanu Reservoir No. 1 Dam Improvements
Honolulu Ahupua`a, Kona District, Island of O’ahu

PROJECT DESCRIPTION:
TMK: 1-9-001: 001 (por.)
The Honolulu Board of Water Supply (BWS) is proposing to undertake priority maintenance and make improvements to the dam embankment and discharge features at Nu’uanu Reservoir No. 1 to meet DLNR Dam Safety Program requirements. These improvements include channelizing the spillway; building a side-loading weir at the spillway inlet; constructing a riprap and concrete apron at the spillway outlet; installing a new outlet works, including an intake structure and 24" diameter discharge pipe; installing monitoring wells on the crest of the dam; buttressing the downstream wells on the crest of the dam; buttressing the downstream slope of the dam embankment with additional earth fill; modifying and building the historic spillway; and adding a new outlet structure in the impound; and modifying the historic profile of the downstream embankment.

PROPOSED PROJECT AREA: Approximately 10.204-acres within a portion of Tax Map Key [1] 1-9-001: 001.

POTENTIAL HISTORIC RESOURCES:
The State Historic Preservation Division’s letter dated February 18, 2025 concurs with BWS’s determination of “Effect, with proposed mitigation commitments” per HAR §13-275-7(a)(2).

If you have any questions or concerns about this project disturbing identified historic properties, please email Michael Domion at capitalprojects@hbws.org within 30 days of this advertisement.

Very Truly Yours,
Ernest Y. W. Lau, P.E.
Manager and Chief Engineer
Honolulu Board of Water Supply

(SA1500613 7/28/25)