Flooding, treaty worry U.S.-Mexico commission

HARLINGEN, Texas — The planned, much-debated fence along the U.S.-Mexico border designed to keep people from crossing the Rio Grande could exacerbate flooding and skew the national boundary, a binational commission said Wednesday.

An impermeable fence between the river and levees, which can be as far as 1-<133>1/2 miles from the river, could cause flooding in addition to violating a 1970 treaty, said Sally Spener, spokeswoman for the International Boundary and Water Commission.

The treaty declared the international boundary at the midpoint of the river and prohibited construction of anything that could deflect or obstruct the water flow and harm the other side.

"If you have a structure that is going to alter the river channel, then you are in effect altering the boundary between the United States and Mexico," she said.

Russ Knocke, spokesman for the U.S. Department of Homeland Security, said the fence could be built in several ways, depending on where it is placed. Some proposed fencing would be impermeable to water.

The United States and Mexico established the commission in 1889 to regulate water use and apply boundary treaties for the shared Rio Grande and Colorado River. Together, the commission has built and maintained international dams and reservoirs, hydroelectric plants, water-treatment plants and floodway projects.

The commission is waiting for the government to submit proposals for the fence's location and materials, Spener said.

The commission hasn't received any documents, including the widely circulated Customs and Border Protection map showing planned fencing along the Texas side of the Rio Grande, she said.

Xavier Rios, of Customs and Border Protection, said the boundary and water commission had legitimate concerns and would be listened to: "Those are all the concerns that will be addressed with the final laydown."