WAILUKU, Hawaii – Maui may be running out of sand, threatening not only its famous year-round beaches but the state's booming construction industry.
Sources of readily available sand may run out within five to seven years, according to a report being prepared for Maui County.
Maui sand is in high demand because it's a key ingredient in concrete and the only material now available for beach restoration projects. About 318,000 tons of sand are dug out each year from inland sources, and 70 percent of it is shipped to the main island of Oahu to feed Honolulu's hungry construction industry .
"When we run out of sand ... the only alternative will be to ship it in from another source, and my first reaction is it will have a significant impact on the cost of concrete," said Eric Yoshizawa, vice president of Ameron Hawaii, which is excavating on some of the last undeveloped dunes.
"It doesn't bode well for the future of affordable housing on Maui," Yoshizawa said.
Local environmentalists and construction industry leaders are urging the county to preserve what sand the island has left. They also want officials to restrict the exportation of sand to Honolulu.
"Anyone who knew about it would know we're running out of sand," said Chip Fletcher, professor of geology and geophysics at the University of Hawaii-Manoa. "It's just surprising it's happening so soon."
About 5.5 million tons of sand have been mined on Maui over the last 20 years, according to the report prepared by consultant Howard Hanzawa for the county Department of Public Works and Environmental Management.
There is still plenty of sand on the island, but it's now inaccessible because it lies beneath development. At this rate, open sand supplies could be exhausted in just under six years, according to the report.
"Maui has had this valuable resource for a long time," Hanzawa said. "But with development over the dunes, we kind of locked up the resource in many areas."
Ameron doesn't plan to conserve sand because it would be too expensive to stockpile for longer than five years, Yoshizawa said.
If the dunes run out of sand, there won't be many alternatives. Importing granite sand or developing a new product out of crushed rock would increase the cost of concrete and give it a less-desirable texture he said.
And for beach restoration, the only other option would be to dredge sand from the ocean floor.
The price of sand already has been climbing over the last decade.
Ten years ago, Grade A sand sold for $5 a ton on Maui and $10 in Honolulu. Now, prices are $20 on Maui and $40 in Honolulu.
"We're having to deal with a corporate world that's looking at bottom-line numbers, and I think they're being very shortsighted," said Mayor Alan Arakawa.