History of Some Significant Dams in Hawaii

Abstract

Until the catastrophic dam failure on Kauai during the spring of 2006, many, if not most people didn't realize that Hawaii had any significant dams. In fact, there are over 130 dams in the inventory that are large enough to be under the State's jurisdiction. Over half of these dams are classified as high hazard dams with the potential to cause loss of life and property should a failure occur. This number may in fact be low. At the time of failure, the Ka Loko Dam was classified as a low hazard dam but subsequently killed seven people and swept away a number of homes. Many of the dams in Hawaii were constructed around the turn of the century (1900) or in the few decades following to supply water for irrigation to support the sugar industry. The consequence of this is that not only are most of the dams old and aging, but many were not constructed with a high level of engineering. Furthermore, the natural soil and foundation materials in Hawaii are typically poor with respect to quality dam construction. Review of a number of dams in Hawaii shows a history of problems, a number of failures and other incidents which have surfaced in recent years. These will be described along with how the State is coping with its aging dam inventory.