East and West Breakwaters
Kahului Harbor, Maui, Hawaii*
Construction and Rehabilitation History
The Kahului Railroad Company constructed the original harbor which
consisted of a berthing area, a dredged channel, and a 400-ft-long
east breakwater (Figure 5, location map).
The first breakwater improvements constructed by the Corps of
Engineers were completed (Figure 6 . These improvements included
a 400-ft-long extension of the east breakwater.
The Corps constructed the west breakwater to a length of 1,950 ft.
Extensions of the east and west breakwaters to lengths of 2,766 ft
and 2,315 ft, respectively, were completed.
Maintenance costs exceeded
,000,000. Routine maintenance and
repair involved approximate restoration of damaged breakwater
to their original conditions.
On 14-17 October
the east breakwater was damaged. Approxi-
tons of rock on the extreme east end were dislodged and
washed into the inner harbor area. Approximately 150 ft shoreward
of the east breakwater light a larger mass of stone was dislodged
and washed into the harbor. This break was on the inside of the
east breakwater and covered an area approximately 75 ft long and
20 ft deep. The Estimated repair quantity was 250 tons.
On 1 April 1946 a tsunami damaged the west breakwater. No details
concerning the damage were found.
*Design conditions are characterized by two primary wave types: (1) North-
east trade winds of 10-20 mph which generate the predominant wave from May to
September. Typical waves are characterized by periods of 6-10
of 4-12 ft. (2) Northern swells which generate the predominant waves from
October to March with deepwater wave heights of 5-25 ft and periods of
Hindcasts and refraction analyses show waves as high as
deepwater waves. Toes of the seaward ends of both
breakwaters are in approximately 42 ft of water. Assuming a design storm
ft mllw and using controlling depth criteria, the design
water level at
wave height for the outer ends of both breakwaters is
(Sheet 1 of