The State DLNR proposes to conduct maintenance on the existing Royal Hawaiian groin to make it a stable structure. The existing Royal Hawaiian groin, located on Waikiki Beach between the Waikiki Sheraton and the Royal Hawaiian hotels, is in an extremely deteriorated condition. Its failure would likely result in the destabilization and loss of 1,730 feet of sandy shoreline located to the east of the groin. The objective of the proposed project is to maintain the groin so that it can continue to support the beach’s intended recreational and aesthetic benefits, facilitate lateral access along the shore, and provide a first line of defense to the backshore in the event of storm wave attack. The existing coastal processes, including the chronic loss of sand and beach recession are expected to continue. The groin would be designed such that future beach maintenance could widen the beach to the width of the 2012 Waikiki Beach maintenance shoreline nourishment project. Beach nourishment is not a component of the present plan.

The proposed groin crest length would be shorter than the existing groin and constructed along the same alignment incorporating a portion of the existing structure as a core wall to prevent sand movement through the groin. The new groin would be constructed with rock rubble mound and a cast-in-place concrete crest cap. The groin would extend 125 feet from the existing seawall fronting the Waikiki Sheraton hotel along the existing groin, and then dog-leg to the east to create a 50-foot-long L-head. The total length (along the crest) would be 175 feet. The groin would be constructed of a single layer of keyed and fit 3,200 to 5,400 lb armor stone over 300 to 600 lb underlayer stone and 30 to 100 lb core stone. Following stone placement, a 5-foot wide by 3 to 5-foot thick concrete crest cap would be constructed to stabilize the crest and provide a modular foundation for future work should an increase in crest elevation be necessary to accommodate sea level rise. The concrete crest cap elevation would be +9 feet mean sea level (msl) on the landward end for the first 40 feet, then transition down to +6 feet on a 1V:8H slope moving seaward, then remain at +6 feet for the remainder of its length. The stone crest elevation would be + 7 feet for the first 40 feet and then transition down to +4 feet for the remainder of the groin length. The existing concrete block groin would be modified as necessary to construct the new groin. The +9 foot nearshore stem elevation, which is 2 feet above the present beach crest, would permit a future 2 feet increase in the beach elevation to accommodate near term sea level rise. No man-made increase in beach elevation or width is currently proposed.

Construction would require excavation of the existing beach adjacent to the existing groin to accommodate placement of the new groin stone. On the construction drawings, this region is approximately between Stations 0+00 and 0+60. Excavated sand would be stockpiled on the beach crest within the Worksite Staging Area, above the +5-foot contour and used to restore the natural beach shape following completion of construction. Rock, rubble and other non-sand material would be removed as necessary to place the new groin stone on the fossil reef platform and disposed of at an approved upland disposal site. A temporary second layer of armor stone may be placed on the east (Diamond Head) side of the groin to provide additional width for a construction work and access platform. Construction specifications would require that the stone be obtained from upland sources (field stone or quarried stone) that is free of waste products, soil or earthen material, organic material, debris and any pollutants hazardous to aquatic life. Any excess materials would be removed and disposed of off-site following completion of construction. A Best Management Practices Plan would be adhered to during construction.

The receiving State water, Mamala Bay, is classified by the DOH as Open Coastal Marine Waters, Class A.

Based on an evaluation of the Section 401 WQC Application, the supporting information, which are relevant to water quality considerations, and when all requirements and conditions contained in this proposed Section 401 WQC are fully complied with, there is a reasonable assurance that the discharges resulting from the proposed construction activities will be conducted in a manner which will not violate the applicable water quality standards and will comply with the applicable provisions of CWA, Sections 301, 302, 303, 306, and 307.

This proposed Section 401 WQC shall expire on midnight, two (2) years from the date of issuance. The Director may, upon receipt of written request from DLNR administratively extend the expiration date of the issued Section 401 WQC. The request shall be submitted at least 30 calendar days before the Section 401 WQC expires. The decision by the DOH to allow an administrative extension will be made on a case-by-case basis taking into account compliance history and impact to receiving State water quality.

Persons wishing to comment upon or object to the proposed determinations or request a public hearing should submit their comments or request in writing no later than 30 calendar days from the date of this notice either in person or by mail, to:

Clean Water Branch
Environmental Management Division
Department of Health
2827 Waimano Home Road #225
Pearl City, Hawaii 96782

All written comments and requests received on time will be considered. If the DOH determines that there is significant public interest, a public hearing may be held after at least 30 calendar days of public notice.

If the DOH’s position is substantially unchanged, after considering all timely written comments and all oral comments at any public hearing that may be held, the DOH will issue or deny the Section 401 WQC, as appropriate, and this action will be final.

Please notify anyone you know who would be interested in this matter.