Amid drought, water flow into key Texas reservoirs reaches zero

Why it matters: At 56% of capacity, the giant lakes are starting to look a lot more half empty than half full — and tensions are starting to rise along the river basin over who deserves water most.

Details: The Pedernales River and the Llano River have contributed zero drops of water into the Highland Lakes for at least two weeks now, per an Axios Austin review of data from the Lower Colorado River Authority (LCRA), the agency that manages the river.

• The lack of rain and inflows is leading to dangerously stagnant water. Last month, Austin officials warned that "people should not drink or ingest water directly from Central Texas lakes" after a dog died, likely from accidentally ingesting harmful algae.

The big picture: The water that flows through those lakes and downstream to the Gulf is the drinking water for Austin and other Central Texas cities, cools the South Texas nuclear reactor and sustains the ecosystem in Matagorda Bay.

• In July, the LCRA opted to cut off lake water for downriver rice farmers.

What they're saying: "The tension will only increase," Steve Box, executive director of the Bastrop-based group Environmental Stewardship, tells Axios.

• After years of comity up and down the basin, lubricated by consistent rains, expect a return of the sometimes angry competition between agricultural, municipal and industrial interests over the region's key resource.

What we're watching: So far, officials in Austin and other cities have imposed only mild watering restrictions. Expect drought rules to be ratcheted up soon, as policymakers play catch up with a record-setting stretch of hot weather.