Updated

Flooding caused by Harvey has toppled two oil storage tanks in southern Texas, releasing about 30,000 gallons of crude oil, authorities said Wednesday.

The spills in DeWitt County were reported by Burlington Resources Oil and Gas. They included a a 16,170-gallon (385 barrels) oil leak near the town of Westhoff and a 13,272-gallon (316 barrels) spill near Hochheim, around 150 miles west of Houston.

It remained unclear if any of the leaked oil was recovered. There was also reportedly an 8,500-gallon (200 barrels) spill of wastewater.

The company, a subsidiary of ConocoPhillips, has reportedly not yet addressed the situation. More damage was expected once the water level recedes, authorities said.

Harvey, which struck Texas on Friday as a Category 4 hurricane and has since declined to a tropical depression, has resulted in the shutdown of more than 20 percent of the country’s oil refining capacity, the San Antonio Express-News reported.

The country’s largest refinery in Port Arthur, Texas, run by Saudi Arabia's state-owned oil company, was shut down Wednesday “in response to increasing local flood conditions." It had already been running at less than half-speed due to Harvey.

Multiple refineries were shut down in Corpus Christi and other parts of South Texas prior to Harvey’s landfall on Friday. Some of the facilities were running again Wednesday, but refineries along the Gulf Coast remained shut down due to flooding, the Express-News reported.

The area between Corpus Christi and the Louisiana border generates about 3 percent of the U.S. economy as it is a vital export market for chemicals and oil.

Gas prices are expected to increase, but the full impact of Harvey will be assessed after the storm and it will potentially take weeks before the energy sector returns to full capacity, market watchers say.

Following the closures so far, gasoline futures increased for a third straight day, by 9 cents to $1.87 a gallon.

Retail gas prices also have increased – up 2 cents Wednesday and 7 cents over the last week. The national average stands at $2.42 a gallon, according to GasBuddy.

“In terms of product price increases, it might get worse before it gets better,” said Rob Smith, an energy analyst with IHS Markit.

The Associated Press contributed to this report.