(...) For more than 60 years, the Addicks and Barker dams have prevented an estimated $4.6 billion in flooding damages by limiting large amounts of water from reaching flood-prone Buffalo Bayou. But the dams, once located in the rural nothingness of Harris and Fort Bend counties, have been pushed to their limits, largely due to all of the people and buildings that currently coexist upstream and downstream of the dams.

In April 2009, during an unnamed weather event that leveled the west side with more than nine inches of rain in 24 hours, the dams exhibited signs of irreversible failure. Five months after the 2009 storms, the United States Army Corps of Engineers, which owns the dams, which are located near the intersection of Interstate 10 and Beltway 8, slapped Addicks and Barker with an "extremely high risk of catastrophic failure" label. The dams are currently two of the country's six most dangerous, according to the Corps.

Despite the Corps' "urgent and compelling" Dam Safety Action Classification I ranking, the local chapter of the Sierra Club, concerned residents and a professional engineer say the Corps has downplayed the risk a member of the Houston Sierra Club says that she accidentally discovered the Level I distinction while researching other matters.

Additionally, in Sierra Club v. U.S. Army Corps of Engineers filed on August 22, 2011, in the United States District Court for the Southern District of Texas, Houston Division the environmental group alleges that the Corps tested fate when, in June 2011, they gave a thumbs-up to the construction of Segment E of the Grand Parkway (Highway 99). While some say the toll road is needed to keep up with fast-growing Houston, environmentalists say that the 15.2-mile segment between I-10 and Highway 290 will coax more concrete from housing and retail projects, which could send more water to the aging dams.

Local environmental attorney James Blackburn, who is representing the plaintiffs in the civil suit currently in the appeals process after a district court sided with the Corps says that if the dams broke, folks would have to deal with a lot more than soiled couches and temporary power outages.

"It could dwarf New Orleans and Katrina," says Blackburn, who adds that the Memorial Drive area, the Energy Corridor, River Oaks, the Texas Medical Center and maybe even downtown could be wading in nasty, disgusting floodwaters.