An engineering report commissioned by the government of the private border wall south of Mission shows it is expected to weaken in the face of flooding.

Those findings are public now after the report was obtained by The Texas Tribune and ProPublica.

The process took 15 months, during which the government claimed an exemption to release the report because it contained proprietary information, the news outlets say.

"That trash rack which is immediately downstream from us at almost a 90-degree angle will become blocked and clogged and cause floodwaters to be redirected at an increased rate of speed and force to our land," Executive Director for National Butterfly Center Marianna Trevino Wright said.

The private border wall overlaps with the federal border wall, less than 4,000 feet away.

The report finds the private wall has foundations shallower than the government wall. It finds that the wall would slide or overturn during a hurricane like 1967's Beulah, and become unstable in the face of smaller, more frequent floods.

"It confirmed what experts had been telling us for over two years now, that not only was the fence based on a flawed design, but the construction was shoddy," Texas Tribune and Propublica Journalist Perla Trevizo said.

Trevizo says it took 15 months and the threat of litigation to get the government to release the report. She says the government claimed it couldn't because it contained proprietary information of the builder.

"Not only is it starting to tilt, but you can see where it's settling," Wright said. "Where the bollards used to be set really straight, they're now doing this."

The wall stands today under this year's settlement agreement between the government, and its owner — the terms, quarterly inspections, new flood gates, and a $3 million bond.

It stands, even if it's liable to collapse.

"Now everyone knows the government knew it as well," Wright said. "They just chose to allow it to stand and be a public hazard."