Nearly six years have passed since Hurricane Harvey flooded the Houston area. It was one of the costliest storms in U.S. history, causing more than $150 billion in damage. This August will mark a critical deadline for thousands of Houston residents who want government compensation after federally built reservoirs backed up into their homes during the storm.

Maria Perez and Lisa Johnson bought their house in northwest Houston nine years ago, not long after they married. Their home was actually within the boundary of the Addicks Reservoir. Neither really thought about what that meant. “When we bought the house, they checked that it had not flooded in a thousand-year record,” Perez said. “So, I guess maybe we weren’t concerned about it so much.”

When Harvey hit, more than three feet of water flooded their home. Johnson lost her grandmother’s China cabinet. Perez lost her wedding dress and suffered from asthma attacks during the cleanup. But the worst affected was their eldest son, then two, who was so traumatized, he wouldn’t talk for a year after the storm. Perez said she wants the federal government to compensate her family so they can move somewhere safer.

“Literally at the end of the block, there’s a sign for the Addicks Reservoir,” Perez said. “Every time I come out (on) my street, at the stop sign, it’s right in front of me, and it’s a daily reminder of what could possibly happen again.”

Rocio and Jose Perez, no relation to Maria, also live within the boundary of the reservoir. And their home flooded too. Rocio Perez said cleaning up the contaminated house made her husband deathly ill. She said doctors told her it nearly cost Jose his life.

“They told him that he was going to die, because he had E. coli, and it had got all in his organs, in his system,” Rocio Perez said.

The two couples joined a lawsuit against the U.S. Army Corps of Engineers. That agency built the Addicks and the neighboring Barker Reservoir back in the 1940s to protect downtown Houston from flooding. A judge ruled the Corps knowingly didn’t buy enough land to adequately store the water in case of a major flood. It had imposed a “flowage easement,” assuming the right to store water on land it didn’t own.

Charles Irvine, co-lead counsel for the plaintiffs, said if residents don’t sue, they’re effectively giving away money. “Those flowage easements will be claimed by the federal government for nothing,” Irvine said.

The judge ruled residents are entitled to compensation, but they must file claims individually. Irvine says the deadline is August 28, six years after Harvey. “People in the upstream area who do not file will lose their right forever,” Irvine said.

Of the estimated 10 to 12,000 property owners flooded within the reservoirs, fewer than half have filed claims to date. Meanwhile, the federal government is appealing the judge’s ruling. The U.S. Department of Justice declined to comment for this story, citing the active litigation.