Texas Gov. Greg Abbott continued to slam the Electric Reliability Council of Texas (ERCOT) on Thursday for what he says are failures to prepare the state for the winter storm that has left thousands freezing in the dark without running water.

But the governor also said he had the responsibility to ensure the nonprofit company functions properly and he vowed reforms.

ERCOT, which operates the state's power grid, said five days before the storm it was ready for the incoming storm, Abbott said at a press conference. The company's winter assessment assured the public there would be enough power to get through winter and it issued a notice to power plants to ensure they were winterized properly, Abbott said.

"ERCOT failed on each of these measures that they said they had undertaken," Abbott said. "Texans deserve answers on why these shortfalls occurred and why they're going to be corrected."

The governor didn't shy away from saying he has work to do.

"I'm taking responsibility for the current status of ERCOT. Again, I find what has happened unacceptable," he said, adding that he's going to task the Legislature with restructuring the way the board works and its membership.

Weeks prior to the storm, a new chair and vice chair of ERCOT's board were elected, he said.

Abbott says the board's membership needs "to be more responsive to the people of Texas."

CNN reached out to ERCOT for comment on the governor's latest statements.

The governor said he signed a major disaster declaration that is awaiting approval from President Joe Biden.

Power was still down for 340,000 Texas customers as of Thursday afternoon -- well below the over 3 million outages a day earlier, according to Poweroutage.us.

ERCOT said in a statement it had made "significant progress" restoring power overnight. Still, the winter storm and ongoing cold were affecting the system's power generation, and rotating outages may be needed over the next couple of days, the company said.

ERCOT officials also said that the power grid was "seconds or minutes" away from catastrophic failure and a complete blackout if not for controlled outages implemented early Monday.

The comments come as freezing temperatures were forecast again for Thursday, extending an already excruciating period.

More than 22 million people across hard-hit Southern states were under a hard freeze warning, indicating that temperatures will be so cold it could lead to further water line breaks. Temperatures are expected to rise Friday, although icing on bridges and overpasses will remain a threat until late Sunday into Monday.

In the meantime, the electricity shortage has broadened to encompass food, water and health crises. Since last Thursday, 16 Texans have died from weather-related circumstances.

Some 13.5 million people are facing water disruptions with 797 water systems throughout the state reporting issues such as frozen or broken pipes, according to Toby Baker, executive director for the Texas Commission on Environmental Quality. About 725 systems are under a boil water advisory, Baker said during a press conference Thursday.

Abbott said he's issued an executive order to investigate ERCOT and is asking the Legislature to mandate a winterization and modernization of the power system along with funding for it.

"Everyone knows how challenging the past few days have been for our fellow Texans," Abbott said. "I want everyone to know that all of us in the state of Texas believe it's completely unacceptable that you had to endure one minute of what's happened. We will not stop until normalcy is restored to your lives."

Spillover effects of no power for days

Several frigid days with no power or heating have led to serious water issues: frozen and burst pipes, disabled water treatment plants and a lack of water pressure.

Houston Methodist West and Houston Methodist Baytown hospitals are still operating without water Thursday afternoon, according to Houston Methodist public relations manager Gale Smith.

"They've been creative, from trucking water in for consumption to collecting rainwater to use for flushing toilets," Smith told CNN.

How you can help the Texas storm victims

Fort Hood city leaders asked residents to conserve 40% of their water during the storm due to water line breaks and subsequent flooding. Del Rio, in southwest Texas along the border with Mexico, put out an urgent message late Wednesday to residents asking them not to flush their toilets or release any wastewater into the sewer system.

Smita Pande, of Crestview, told CNN she and others may have to use melted snow for drinking water when their bottled water runs out.

"We didn't anticipate the water to be shut off, but once it did, we assumed a 'worst case scenario' type of thing and just grabbed snow off the balcony and put into kettles and pots to use for drinking water in case we don't get water back anytime soon," Pande said. "If the power outage is any indication of how long that'll be, then we are going to be boiling snow for a while."

The outages have also led to food shortages as Texans scramble for needed supplies and scrounge for a hot meal.

"Grocery stores are already unable to get shipments of dairy products. Store shelves are already empty," Texas Agriculture Commissioner Sid Miller said. "We're looking at a food supply chain problem like we've never seen before, even with Covid-19."

Philip Shelley, a resident of Fort Worth, told CNN that he, his wife Amber and 11-month-old daughter, Ava, were struggling to stay warm and fed. Amber is pregnant and due April 4.

"(Ava) is down to half a can of formula," Shelley said. "Stores are out if not extremely low on food. Most of our food in the refrigerator is spoiled. Freezer food is close to thawed but we have no way to heat it up."

Why the electric grid neared collapse

The widespread outages stem from a weather disaster coupled with an unprepared infrastructure.

A winter weather system brought unusually frigid temperatures to much of the central US over the past few days. The deep freeze caused demand for power and heating to skyrocket even as it knocked out Texas's natural gas, coal, wind and nuclear facilities, which were not ready to function in such cold weather.

The storm has caused serious outages across the country, including in Louisiana, Mississippi and Kentucky. But the outages were most severe in Texas because the state runs on its own electric grid, ERCOT -- a way to avoid federal regulation -- and cannot easily borrow power from other states.

The lack of winter preparedness has long been an issue for ERCOT's power system. Ten years ago, a bitter cold snap caused over 3.2 million ERCOT customers to lose power during Super Bowl week. A 350-page federal report on the outages found that the power generators' winterization procedures were "either inadequate or were not adequately followed."

As with any systemic failure, the blame is spreading far and wide. Members of the Federal Energy Regulatory Commission said they would partner with the North American Electric Reliability Corporation, a nonprofit organization, to investigate the failings.

Abbott said Wednesday afternoon that an investigation of ERCOT is slated to begin next week.

Abbott, former Gov. Rick Perry and the Lone Star State's Republican leaders are in turn facing heated questions over their misleading claims about renewable energy and why they didn't act to protect the electric grid given the clear warnings. US Sen. Ted Cruz, meanwhile, flew with his family from Houston to Cancun, Mexico, on Wednesday.

"We have learned really in a tragic way that ERCOT and the state had not prepared to have enough backup power to have resilient power supply to face the historic weather that we all really knew was coming," Harris County Judge Lina Hidalgo said.