A reservoir that provides water to the Rio Grande Valley celebrated its 70th anniversary on Friday.

The Falcon Dam was dedicated 70 years ago by the presidents of the United States and Mexico on Falcon Lake. It benefits the Valley communities downriver with a steady water supply.

The investment came with a sacrifice for people in a small Mexican village called Guerrero. Residents of that community ended up moving for the project to be completed.

Many families and ranchers in the United States lost their grazing land, and had to move for the massive lake that would benefit others.

Both countries contributed money and sweat to build the dam, which was planned at its peak to be 60 miles long and 11 miles wide.

It stopped floodwaters from rushing down the river into the Valley, and gave farmers a chance to control irrigation.

The water levels at Falcon Lake are nearly as low as they've ever been. It’s also low at the other Valley dam, the Amistad Reservoir.

“In terms of a solution, we need a lot of rain,” Zapata County Judge Joe Rathmell said. “Of course, we need a little better cooperation from the Mexican government."

Officials say they're working to make sure obligations with a 1944 treaty to have water delivered into the United States from Mexico every five years be met.

Watch the video above for the full story.

READ MORE: Federal government asking Mexico to release water to the Valley under 1944 treaty