The company made its second attempt to recruit a chief executive in January, advertising on Utility Week’s job section, but have decided to stick with Venning who joined the firm in April 2010 as director of customer service delivery.
Its initial recruiting campaign last October failed, when six shortlisted candidates were considered unsuitable for the £150,000 post.
Séan Hogan, NI Water chairman, said: “Throughout this process we have always made it clear we were determined to make the correct choice and in Sara we are confident that we have found a highly skilled and experienced individual and the right person to lead this complex and essential service.”
The company, which has seen four chief executives at its helm since it was set up six years ago, has been marred by a number of failings at boardroom level since its creation in April 2007.
The last chief executive, Trevor Haslett, stepped down from his post at the end of August citing “personal reasons”.
Haslet had been appointed acting chief executive in January 2011, after Laurence MacKenzie resigned over mishandling of a cold weather crisis that saw 450,000 lose their water supply.
Haslett threatened to step down in autumn 2011, reportedly due to dissatisfaction with his £130,000 salary, but stayed on.
In 2010 the then chairman Chris Mellor and three other board members were sacked amidst controversy on how the company was awarding contracts.