Crews using heavy machinery will begin pushing 3,400 cubic yards of sand around Makaha Surfing Beach today to prevent the kind of erosion that each winter jeopardizes the beach’s lifeguard stand, parking lot and trees along Farrington Highway and puts people at risk for injury.

In severe winters, erosion creates a 5- to 6-foot drop near the beach parking lot that could cause serious injury, said state Sen. Maile Shimabukuro (D, Nanakuli-Makua), who helped bring together private, state and city entities to move the sand over the next few days.

The work is necessary "to preserve one of the most famous surfing beaches in the world," Shimabukuro said Sunday.

Over the next few days, crews will build a sand dune that will be used to replenish sand lost during the winter months, said Chris Conger, a coastal land specialist with the University of Hawaii’s Sea Grant Program.

All of the sand that will be pushed into a dune came from Makaha Surfing Beach, Conger said.

"We are not robbing Peter to pay Paul with sand from somewhere else," he said on Sunday. "We’re taking sand from our widest profile of the beach at the end of summer and pushing that sand to create a dune."

The sand that’s moved south with the winter swells normally would replenish itself when the seasons — and swells — change, Conger said.

But the barrier created by Farrington Highway prevents the sand from naturally returning north, Conger said.

Similar work that was done in February and in February 2010 showed the potential for "pushing" sand to replenish the beach park, Shimabukuro said.

But local residents suggested that the end of August — between the winter and summer seasons — represented the best time of year, she said.

"The work that was done in February was sort of like a Band-Aid," Shimabukuro said. "The erosion was very severe."

Looking back, Conger said, "The years they don’t push sand are the years they have the worst erosion problem against the roadway. People are walking off — and even driving off — the edge of road. It’s significant. It’s not trivial."

Shimabukuro will monitor the sand at Makaha Surfing Beach this winter, but hopes the work recurs every August.

"Before the state built Farrington Highway right down the middle of the beach, there was so much sand in Makaha that there were sand dunes that went all the way mauka," Shimabukuro said. "This is a man-made problem. We’re just trying to help nature along."