Drought conditions in South Texas have brought increased pressure on Mexico to make good on its commitment to deliver water to the U.S. under a 1944 treaty. But an analysis by the agency that enforces that treaty shows that water from U.S. sources has significantly diminished over the years.

The region's two major reservoirs are at record-low levels and agriculture leaders are worried the citrus industry could be devastated this summer.

Texas’ biggest single solution to providing enough water for its soaring population in the coming decades is using more surface water, including about two dozen new large reservoirs. But climate change has made damming rivers a riskier bet.

The quagga mussel — a close relative of the zebra mussel that’s already invaded 33 state lakes — was detected in Texas for the first time.