Ilima Loomis of The Maui News reports that Maui's sand is expected to run out. "The vast system of inland sand dunes that stretches across Wailuku has largely been covered by development, and what's left is being mined — about 318,000 tons of the stuff dug out and used each year, 70 percent of it shipped to Honolulu." At that rate, the last available sand on the island will be gone within five to seven years. Sand is a key ingredient in concrete, and a shortage will mean importing a substitute, increasing the cost of construction across the state. It's also the only material available that can be used in beach-restoration projects. Sand has been mined on Maui since before World War II, and for years it was excavated in limited amounts from beaches in the Paia area to produce lime at a nearby kiln.