Fifty-three days after Hurricane Helene, residents of Asheville can safely drink their tap water without boiling it. Why did it take so long? And, tribes’ historic lands on the Gulf Coast are being lost to the sea. To slow it down, one tribe has turned to oyster shells.The Struggle To Restore Drinking Water After Hurricane HeleneWhen Hurricane Helene barrelled through the southeastern US in September, it dumped an estimated 40 trillion gallons of water on the region. That resulted in immense flooding that destroyed roads, buildings, power lines, and other infrastructure.And it also impacted the region’s potable water supply. For weeks, residents in Asheville, North Carolina, didn’t have access to clean drinking water because the extensive flooding washed large amounts of sediment into the local reservoir. As of Monday, limited access to potable water was restored, marking the first time in 53 days that local residents didn’t have to boil tap water to drink it.Before that access was restored, we heard from listeners Sarah and Alison in Asheville who had their own questions about the water quality in their city, and the science behind sediment issues in a local reservoir.Guest host and SciFri producer Kathleen Davis is joined by Dr. Sarah Ledford, associate professor of geosciences at Georgia State University, to figure out why it can take so long for cities to clean their potable water after a storm like this and what other regions expect from the aftermath of future extreme weather.Using Oyster Shell Reefs To Counter Sea Level Rise In LouisianaOn a hot Friday morning, the sun beat down on volunteers gathered at the edge of the water in southern Plaquemines Parish. They passed heavy sacks of oyster shells to each other down a line. The volunteers loaded the shells onto boats to use them for building an oyster reef to help slow land loss in Grand Bayou Indian Village.“The oyster reef is a living thing. Baby oysters are going to attach to it. It’s going to grow. It’s going to become bigger,” said James Karst with the Coalition for Coastal Louisiana, the organization that built the reef. “But when the sea level rises, because oysters are growing on it, it will grow vertically as well, so it will continue to add protection.”Louisiana’s land loss is an existential crisis for many of the tribes who live along the coast. Grand Bayou Indian Village, a small community, home to the Atakapa-Ishak/Chawasha tribe, is watching its lands wash away. Nearly 1,000 people lived in the village in the 1940s, but now there are only about a dozen homes raised on stilts right along the edge of the bayou. Boats are the only way to get around.“You can look at the GPS and it will indicate a different color for where land is,” said Karst. “You’ll be looking at this on the screen, then you’ll look up and there is no land there. It’s just open water.”Volunteers built the reef by stacking bags of recycled oyster shells in the water, up and down the shoreline. The shells came from restaurants in New Orleans. The coalition recently expanded its oyster recycling services to Baton Rouge.Read the full story at sciencefriday.com.Transcripts for each segment will be available after the show airs on sciencefriday.com. Subscribe to this podcast. Plus, to stay updated on all things science, sign up for Science Friday's newsletters.