The grassy yard behind Jennifer McPeak’s house was slipping into Marler Bayou, its edge giving way as waves beat against it. She planned to stem the losses with a $14,000 seawall until a Florida permitting official suggested an alternative — marsh seedlings and bags of oyster shells arranged to blossom into a “living shoreline.” A few years later, crabs and snails crawl among the oysters and grasses in McPeak’s living shoreline, which occupies nearly the width of her shoreline. Fish school in it when the tide is up. The effects of years of erosion have been reversed; sand is being trapped in the yard when storms and floods hit instead of being washed away. “We’re clawing back land here,” McPeak said, standing on sandy lawn near the end of a fence, where it used to hang over the water. “I’m loving rough water events now, because I think, ‘Hoo hoo hoo, free sand. So excited.’” Centuries of dredging, diking, and development have replaced wetlands throughout the U.S. with more than 10,000 miles of rocks, concrete, and metal. For every seven miles of coastline in the Lower 48, scientists in North Carolina calculated that about one mile is hardened with a seawall, bulkhead or other hard structure to protect land and property. Rising costs from flooding and erosion are prompting Americans, military bases and government agencies to opt for more natural alternatives. State and federal governments are changing permitting rules and taking other steps to encourage the switch, which can improve water quality, support fisheries and protect against storms and rising seas. After marsh grasses were planted to reduce erosion at the Needle Rush Point condominium community, which fronts both sides of Perdido Key in Pensacola, residents began seeing more wildlife. “We’re planting needlerush and cordgrass to create a root barrier,” said Jeanette Pollett, manager of the Needle Rush Point Association. “With the grass, you get everything else. There’s more fish in the area, and the dolphins are entertaining.” Since permitting rules on living shorelines were eased a little more than a year ago, 34 small living shorelines, typically under 500 feet, have been approved or built in Florida, according to U.S. Army Corps of Engineers figures, with the Destin area east of Pensacola emerging as a hotspot. That’s more than half of the 60 approvals issued nationwide during the same period; the rest were farther west on the Gulf Coast or north along the East Coast, including 13 in the Norfolk area.