(Reuters)

The Texas energy industry braced for Hurricane Beryl’s impact on Monday as the powerful storm forced the closure of key oil and gas shipping ports, slowed refining and prompted the evacuation of some offshore production sites.

Beryl made landfall near the coastal town of Matagorda, Texas, packing maximum sustained winds of 80 miles per hour (129 kilometers an hour) and posing problems for the heart of the country’s energy sector.

The storm had strengthened to a Category 1 hurricane before landfall but was expected to weaken rapidly, turning into a tropical storm later in the day.

Located about 85 miles south-southwest of Houston, Texas, the storm’s center was forecast to move over eastern Texas on Monday, before passing over the Lower Mississippi Valley into the Ohio Valley later in the week, the U.S. National Hurricane Center (NHC) said.

Texas is the largest U.S. oil and gas producing state, accounting for some 40 per cent of oil output and 20 per cent of gas production.

Power outages in Texas topped 1.4 million, according to PowerOutage.us and local utilities. Texas-based electric utility CenterPoint had more than 1.3 customers without power, but said it had restored power to over 300,000 customers over the past 24 hours.

Flash flood warnings were issued for several counties in southeastern Texas including in Houston, where many U.S. energy companies are headquartered, due to thunderstorms producing up to 6 inches of rain, with 2-4 more inches expected. Heavy winds lashed the city on Monday morning as local streets flooded, according to a Reuters witness.

Over the weekend, the port of Corpus Christi, the country’s leading crude oil export hub, closed operations and vessel traffic in preparation for Beryl. The ports of Houston, Galveston, Freeport and Texas City were also shut ahead of the storm’s landfall.

Enbridge Inc, which runs crude oil export facilities near Corpus Christi, said it had activated emergency plans for assets along or near the U.S. Gulf Coast.

Freeport LNG, the third largest liquefied natural gas facility in the U.S., said over the weekend it had ramped down production and would resume operations after the storm had passed.

Formosa Plastics, meanwhile, experienced a malfunction with a gas compressor system during a shutdown for the storm at its Point Comfort facility, according to a state regulatory filing. The company did not immediately respond to a request for comment.

Citgo Petroleum Corp reduced production over the weekend at its 165,000 barrel-per-day Corpus Christi, Texas, refinery, sources said.

Marathon Petroleum said it had comprehensive plans in place to protect staff, assets and communities during severe weather, but declined to comment on its 585,000-bpd Galveston Bay refinery operations. Chevron said it had hurricane preparation procedures in place to ensure safe operations at its Pasadena refinery southeast of Houston, but otherwise did not comment on operations at the plant.

LyondellBasell declined to comment on the status of its 268,000-bpd Houston refinery.

Shell and Chevron said they had shut production or evacuated personnel from their Gulf of Mexico offshore platforms.