Northern Ireland government ministers are due to meet to draw up plans for an inquiry into the water crisis that hit the region.
The chief executive of Northern Ireland Water (NIW) Laurence MacKenzie resigned after a marathon sitting of the government-owned company's board.
He said: "I believe firmly in the principles of responsibility and accountability; it is for that fundamental reason I have decided to pursue this course of action."
But his decision to step down over the organisation's mishandling of the episode has failed to end the political controversy and a Stormont scrutiny committee will also meet to discuss the fallout.
Arctic weather conditions around Christmas gave way to a rapid thaw that caused hundreds of burst pipes in the water supply system, but NIW was criticised for its failure to handle calls for information from thousands of stricken families.
Regional Development Minister Conor Murphy said Northern Ireland's Utility Regulator was to probe the handling of the crisis that saw thousands of homes left without running water.
"The regulator is an established independent body which already has a statutory duty to regulate water and sewerage services," he said. "It is therefore suitably qualified and has access to the range of required industry skills and expertise to conduct the review. The Executive will consider these proposals at its meeting."
Mr Murphy said the regulator would set the terms of the inquiry and report back to the Stormont Executive by the end of February, though it is possible proposals for reform could be made at an earlier date. His department is responsible for NIW and he has been heavily criticised for its handling of the events.
The DUP's Gregory Campbell said Mr Murphy had to be held accountable at the Assembly.
"I think it's fairly clear, that the degree of incompetence and the shambolic nature of Northern Ireland Water's response is totally and utterly inadequate," he said. "And at the end of it there is one person who carries the can. Whatever way we cut this, there is one person who carries the can, and that is the ministerial responsibility at the head of the department."
