SANTA ROSA – Two years in a row, catastrophic flooding in the Rio Grande Valley has cost hundreds of thousands of dollars.

It's dry now, but months ago FM 506 was inundated by flood waters. It happened quickly, but the effects are felt months after.

Carmen Ponce says they were told by the county to go back to their homes “at their own risk." She says they didn't know they lived in a low-lying area until the county told them after the flooding.

The elevation in Santa Rosa is only 50 feet above sea level; some places only lie at 26 feet above sea level in Cameron County. The highest point in the county is 60 feet.

They're not the only ones in a low lying spot in Cameron County.

Because the Valley is so flat, water will pool in these low lying areas.

In July, Cameron County told CHANNEL 5 NEWS, the entire county is considered to be a flood zone, and that it’s explained to people when they get a permit to build.

Some residents also have to get a special evaluation and build at a higher elevation, depending on the area they're building in.

County officials told us, even the ones that meet county code requirements would still have flooded with last summer's rain.

An associate professor and department co-chair for the civil engineering department at the University of Texas Rio Grande Valley, Dr. Junseok Ho, has been working on modeling inland rainfall and storm surge.

Ho showed us just how devastating historic rain can be to parts of the county spared in the past. This time the model showed us a once in 100 year flood event.

Ho says whether its historic rainfall or a hurricane, flooding in the valley is prevalent due to its elevation.

Still, ponce says she will continue to rebuild as what the county continues to call her "own risk."

For more information watch the video above.