Evidence Of Large Karst Sinkholes In Ewa Gentry Community Properties - Updated to 2021
Ewa Cultural History Historian John M. Bond
A fascinating look at some of the major sinkholes in the Ewa area.
The entire Ewa Plain is approximately 25 square miles of sinkholes and caves,
some very big and some very small.
The Ewa Gentry area was built
over numerous huge karst sinkhole caves as early cultural oral history
will tell you, and also visible on old USGS maps. One of the really big ones still
exists and has never been filled in.
Holomua Elementary School which is directly north of this big
sinkhole is known for being haunted with mysterious sounds and
noises. This is likely due to the large underground karst cave
channels that carry rainwater from the mountains and dumps into
the shoreline.
This area has one of the largest subsurface waterways
that emptied into the Puuloa reef area. Puuloa was known for
large caves, including royal burial caves, and the massive rain
water discharge feed the copious amounts of limu that once
existed there.
Limu feeds the ecosystem of the fisheries however
much of this has since been destroyed by developments.
Image Below: Holomua Elementary School seen mauka (north) of this
huge Ewa Plain sinkhole cave site.
It has been used as a flood drainage basin- with the water traveling out through
the porous karst to the Ewa Puuloa shoreline near the entrance to Pearl Harbor.
Huge water problem soaks Ewa community - Honolulu Star Advertiser October 2021
This particular development in the Honolulu Star Advertiser story of October 2021
is directly south of a huge Karst sinkhole cave site as was documented in
this Kanehili Ewa Karst blog in 2014 and now updated.
One of the largest still existing huge deep sinkhole caves is directly adjacent
(north) to this Gentry development project. I was told many years ago that
this was left undeveloped because it drains water from the nearby developments.
However many others like it were filled in and over time rains cause the coral fill to
subside and wash away exposing pipes underground to corrosion and breaking
under stress which causes water leaks and eventually breaks.
This happens all over Oahu's south shore because it is all ancient
coral reef and the subsurface water erosion is continuous
causing water and sewer pipes to corrode and break, usually flooding streets.
coral reef and the subsurface water erosion is continuous
causing water and sewer pipes to corrode and break, usually flooding streets.
The karst in this area is especially dense with lots of evidence of ancient sea creatures
This site along Kapolei Parkway was later filled up and turned into Geiger
park as they probably didn't want to put homes over it.
This site exhibits classic groundwater near the surface as it is near the
Kalo'i waterway that empties by Hau Bush Ewa shoreline park.
