Resaca (channel)

Resaca is the name given to a type of oxbow lake in the southern half of Cameron County, Texas.

[1] The resacas constitute former channels of the Rio Grande and are naturally cut off from the river, having no inlet or outlet.

Every year during spring, melted snow would flow into the Rio Grande, bringing seasonal flood waters to the most southern tip of Texas.

When the seasonal flooding ended and the river retreated, the newly formed oxbow lakes remained, creating resacas all throughout the Rio Grande Valley.

The latter is the most plausible explanation given that the primary geological function of a resaca is to divert and dissipate floodwater from the river.