By Ruby Pap

Ha‘ena, December 2015. Photo by Ruby Pap

Ha‘ena, December 2015. Photo by Ruby Pap

In my humble opinion, Kaua‘i has the most amazing beaches in the world. Besides their stunning natural beauty, beaches provide important natural and cultural resources. Forty seven percent of the island’s perimeter is made up of sand, more than any other Hawaiian island. These beaches provide essential habitat for wildlife and act as a buffer between land and sea. They are also the foundation of our recreational and cultural activities and are the major draw of our tourism economy.

Kaua‘i’s carbonate beach sand is derived from nearshore reefs. While it has never been dated here, based on radiocarbon dating on O‘ahu, it’s assumed our sand to be older than 1,500 years. The implication of this aged resource is that it is limited in quantity and should be carefully managed. Beach erosion is a growing concern.

Pono Kai Seawall repair and beach nourishment project, December 2015. Photo by Ruby Pap

Pono Kai Seawall repair and beach nourishment project, December 2015. Photo by Ruby Pap

Historical beach erosion trends are documented in the Kaua‘i Shoreline Study Erosion Maps developed for the County of Kaua‘i by Dr. Chip Fletcher with the University of Hawai‘i Coastal Geology Group at www.soest.hawaii.edu. Researchers analyzed historical aerial photographs dating back to 1926, mapped the shorelines using geographic information systems and calculated erosion rates for all the sandy beaches.

This important work contributed to the U.S. Geologic Service’s National Assessment of Shoreline Change for the Hawaiian Islands, which concluded 71 percent of Kaua‘i’s beaches are chronically eroding, with 6 kilometers completely lost since the early 20th century. Based on the 2012 studies by Fletcher and Brad Romine, nearly all beaches lost are due to the presence of human-engineered shoreline protection (seawalls, revetments, etc.).