A resident tosses firewood as people line up to load up Wednesday in Dallas. Millions of people in the US have been hit by rolling blackouts or the complete shutoff of electricity in Texas caused by a winter storm. Photo: AP

A series of severe winter storms over the past few days have left the US state of Texas struggling with massive power outages and disruptions of basic need supplies.

The storms have led to freezing temperatures and widespread power blackouts, affecting 900 public water systems in 164 counties with nearly half of the population in the state facing water disruptions, said the Texas Commission on Environmental Quality on Thursday.

According to local media reports, some Texans have completely lost access to running water since Tuesday. Many cities, such as Houston, Dallas, Austin and San Antonio, have issued notices on their websites urging residents to boil water before using.

In a local H.E.B. supermarket, empty shelves were seen Wednesday in the bottled water section. Bread and canned food were also in short supply as people tried their luck to stockpile in the shop that stayed open.

The Texas Tribune published a story on Wednesday saying that people across the state were using up supplies they had stockpiled and losing more as items started to spoil in dark refrigerators.

In the state capital of Austin, a local resident told The Texas Tribune that a Target supermarket was completely out of food on Wednesday, with no sign of additional shipments arriving or employees restocking shelves.

School districts across the state have halted meal distributions to students for the next several days, whereas universities remain closed for the rest of the week, the media report said.

Meanwhile, fruit and vegetable crops in the southern part of the state have frozen due to the severe weather, said the report.

Texas Agriculture Commissioner Sid Miller said Tuesday in a statement that dairy farmers around the state have been pouring 8 million US dollars worth of milk down the drain every day because they lacked the power to turn it into dairy products.

Cattle growers across Texas have been out of feed, while lack of available natural gas has caused some chickens and calves to be frozen to death, Miller said.

On Thursday, Texas Governor Greg Abbott said at a press conference that state officials are working to restore the supply chains for grocery stores and restaurants.

"They will have more food available to them," Abbott said. "One thing that will aid in replenishing those stocks is that the roads are more passable."

According to poweroutage.us, a website that tracks, records and aggregates power outages across the United States, nearly 350,000 out of the over 12 million customers tracked in Texas had been out of power as of Thursday afternoon.

Austin Energy, a publicly owned utility providing electrical power to Austin and surrounding areas, reported on Thursday that 13 percent of its energy customers were without power, down from more than 40 percent on Monday.

Besides, less than 2 percent of Houston was without power on Thursday, down from around 60 percent on Wednesday, local media reported.

However, those still without power are likely to be affected by ice storm damage on the power distribution system, which needs to be manually restarted after it was forced to shut down, Dan Woodfin, senior director of system operations at the Electric Reliability Council of Texas, said Thursday in a statement.

According to media reports, at least 30 people have died due to the severe weather in Texas and other US states in the past few days.

The National Weather Service, an agency of the US federal government, issued a Hard Freeze Warning for northern Texas on Thursday morning, which is in effect from 9 p.m. local time on Thursday until 9 a.m. Friday.

The agency warned that the severe conditions "will result in damage to exposed pipes and additional water main breaks are possible."

According to weather forecast, Houston's temperatures will drop below freezing on Friday and Saturday mornings, and will stay well above freezing starting Saturday night.