Honu'apo Park Resource Management Plan

Honuÿapo Park Final Resources Management Plan
flooding on the subject property. An irrigation system developed and formerly
maintained by the sugar plantations of Kaÿü has affected the surface hydrology of
the area and, according to verbal accounts, decreased the number of flooding
events at Honuÿapo. With the shutting down of the sugar industry in Kaÿü and the
subdivision of plantation lands into smaller parcels, the irrigation system is no
longer maintained.
2.3.3 Natural Hazards
Volcanic hazard in the vicinity of Honuÿapo is assessed by the USGS as “6” in the
southern and central portion of the park, and “3” in the northernmost zone of the
park, on a scale of ascending risk from “9” to “1”. This moderate to high hazard
designation is based on the fact that Mauna Loa is an active volcano, having last
erupted in 1984.
In terms of seismic risk, the entire Island of Hawai‘i is rated Zone 4 Seismic Hazard,
which means it is at risk from major earthquake damage, especially to structures
that are poorly designed or built. The most significant earthquake occurring in Kaÿü
in recorded history was in March and April 1868. Written accounts of Kaÿü
residents attest to the tremendous damage caused by the earthquakes and ensuing
tsunami. A written account by C. J. Waialoha (Ka Nupepa Kuÿokoÿa, April 11,
1868), a Hawaiian resident of Kaÿü describes the disaster (Handy et al. 1991:566):
… The earthquakes were terrible from the 27 th [of March] to the
30 th . The earth shook constantly. We had never before known
anything like this. The stones on our beaches and the cliffs are
scattered and broken… The famous cliffs of Pohina [at Honuÿapo]
were broken in places and some of the natives there feared a
similar fate… At three o’clock on Thursday, April 2, came a great
quake which made it impossible for man and animals to stand
upright. The earth below rose to the sky like a cloud, from the land
slides; big trees toppled over; gulches were filled and houses
collapsed… fifteen minutes after the earthquake, a tidal wave arose,
which killed a number of people. Those who died numbered 46
and those who barely escaped are not numbered… When the sea
ebbed, all kinds of fish were left ashore, except the whale and the
shark.
The houses at Kaÿaluÿalu, Paiahaÿa, Honuÿapo, Hokukano,
Kaÿalaiki, the two Hilea, Ninole, Wailau, Punaluÿu, and as far as
Keauhou, were all swept away by the sea.
The 1868 earthquake that caused the destructive tsunami was estimated to have
had a magnitude of 7.9. Another tsunami in 1946, generated by an earthquake in
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