Bio Diversity: The Moiliili Karst Formation
The Moiliili Karst Formation is a pie shaped wedge that starts at the University of Hawaii lower campus and extends to approximately Kapiolani Avenue.
This entire section is a limestone base that was formed from an old coral reef. Rainwater runoff from Manoa Valley has caused the limestone to erode, forming the present day karst caves that lie underneath the busy University / King Shopping complexes.
According to Frank Howarth, stresses in a cave environment include, “perpetual darkness and humidity, lack of important environmental cues, complex mazelike living space, stressful or even lethal gas mixtures, patchy food resources, barren rocky substrates, wet and slippery vertical surfaces, and occasional flooding.”
The primary food resources in caves include organic substances that are brought inside by water and gravity. As William Halliday (pers. comm.) observed, the fish inside the (Moiliili) cave were eating something that dripped from a dribble of water. He also noted that “biota is concentrated near the entrance. Large and small roots are present, with mycelia present on some” (Halliday 1994).
Many residents of the Moiliili area are unaware that just a couple meters below their feet, cars, houses, and businesses lies a truly amazing formation. The Moiliili karst formation is not only a “natural laboratory for a largely unstudied groundwater zone,” but also important is the “integration of drainage and economic importance” (Halliday 1998:145).
History of Moiliili Karst
The Karst was an integral part of the economy and world above it. There were several ponds that were fed by karsic springs. One was located west of University Avenue, upslope of Beretania Street. The Kanewai underground pond was important to Hawaiian culture, because its water was said to have healing properties.
Originally the pond was a favorite of Queen Kamamalu (sister of Kamehameha IV and V). The pond served as an enjoyable picnic site for the Queen and her brothers. Hawaiian royalty loved swimming in the ponds, which were also said to have healing powers (Willows Flyer: Appendix A).
The pond became the site of the Willows restaurant, and served as an attraction to customers. It was stocked with koi, which interbred with the existing fish creating a school of colorful fish (Halliday 1998).
The 1934 Dewatering
In 1934, a construction endeavor downslope struck a master conduit of the karst. This caused massive water drainage of the upslope area (Halliday: 1998). According to William Halliday (1998:143), “for more than four months, an average of 3.8 x 107 L was pumped daily before the hole could be sealed and construction resumed.”
The total amount pumped before the leak could be sealed was greater that one billion gallons of water (Halliday 1997).
The lowering of the water table has had several consequences on the surrounding area. The dramatic changes in the karst from before 1934 to present time are a result of the dewatering. There is assumed to have been considerable economic loss as sidewalks split, water and gas mains ruptured, trees sank, and houses rose and settled (Halliday 1998).
The spring feed ponds vanished within 24 hours, taking some fish into the karst, while leaving others stranded. There have been several instances of collapses since the dewatering. One instance involves the Standard Trading store falling through the ground into the karst below it (Watanabe 1996).
Another instance involves the emergence of a large cavern downslope from the King-University intersection. Some fish that disappeared from the Hausten Pond were seen there (Halliday 1998).
Oahu Karst Cave Photo and Video Links:
The Moiliili Karst Formation http://explorebiodiversity.com/Hawaii/hikes/Moiliili/cavemap.html
http://explorebiodiversity.com/Hawaii/hikes/Moiliili/caveorganisms.html
Moili'ili Karst Cave Exploration http://www.alohafrom808.com/2012/06/moiliili-karst-cave-exploration-june-2012/
Moili'ili Karst Exploration http://notsogreathikingblog.blogspot.com/2012/06/moiliili-karst-exploration.html
http://www.youtube.com/watch?feature=player_embedded&v=RrGTMYk5cXI
Moiliili Karst http://easyhikerhawaii.blogspot.com/2012/07/moiliili-karst.html
Mōʻiliʻili Karst (Mōʻiliʻili Water Cave)http://totakeresponsibility.blogspot.com/2012/12/moiliili-karst-moiliili-water-cave.html
