(Adds comments from energy companies)
By Kristen Hays
HOUSTON, June 15 (Reuters) - A tropical disturbance packing heavy rains in the Gulf of Mexico was slated to drench the coast of Texas just weeks after floods killed about 30 people in the state, the National Weather Service said.
Flash flood watches were in effect for central Texas and in the Houston area, regions where flooding last month turned streets into rivers, submerged thousands and vehicles and led to swollen rivers that ripped scores of houses off their foundations. Louisiana was bracing for flooding as well.
Heavy rain hit parts of Texas over the weekend, pushing already-high rivers a little closer to spilling over their banks.
In the Houston area, rain could total as much as 10 inches by Thursday.
The National Weather Service said thunderstorm activity in a low pressure system in the south-central Gulf of Mexico grew more concentrated early on Monday, and a Hurricane Hunter aircraft was deployed to collect weather data.
Meteorologists said the disturbance, which has an 80 percent chance of becoming a named storm, would lash the Gulf Coast with rain through Tuesday.
In preparation, Chevron Corp and Royal Dutch Shell have evacuated non-essential workers from oil platforms, but they have not shut in production in a basin responsible for nearly a fifth of U.S. crude output.
Chevron is the No. 3 oil producer in the U.S. Gulf, and Shell is No. 1. Second-ranked BP Plc said it was monitoring the storm, but operations continued as normal.
Other operators, including Hess Corp, Exxon Mobil Corp and Murphy Oil Corp also said they were watching the weather. BHP Billiton said it was not planning to remove non-essential workers, but would start if necessary.
Williams Cos Inc., which operates a platform and big pipeline operations in the Gulf of Mexico, said it had not shut in production.
More than 45 percent of U.S. refining capacity is located along the U.S. Gulf Coast, which also is home to about half of total U.S. natural gas processing capability. (Additional reporting by Jon Herskovitz; Editing by Terry Wade and Lisa Von Ahn)