McAulay was formerly chief executive of waste management company Viridor, but announced in September that he was leaving to “pursue other opportunities”.
Having also held the post of managing director of Capital Programmes at United Utilities, McAulay has extensive experience in the UK regulated utility, construction and environmental services sector.
He also has substantial experience of running privately-owned entities both in the UK and overseas. He comes with a “demonstrable track record of achieving strong operational results and transformational change”.
Commenting on his appointment, McAulay said: “This is an exciting time to be joining Southern Water. We provide essential services for our customers but we must improve to meet their expectations.
“We must also strive to innovate and meet the twin challenges of climate change and population growth, while growing trust and confidence in the water and wastewater services we provide.”
Southern Water chairman Robert Jennings said: “I am delighted to welcome Ian McAulay to Southern Water as our new chief executive. It’s an exciting time for the organisation as we build on solid operational improvements over the last few years and look to deliver improved customer service.
“Ian brings with him extensive experience of managing large complex organisations and overseeing the delivery of many sizeable capital intensive projects in a regulated industry.”
“Ian McAulay has demonstrated that he is an innovative leader with outstanding experience in developing and implementing business strategy. He joins Southern Water at a time of significant change in the water sector: the competitive market is opening in water and bio-resources, and the company is preparing its business plan for the next review period.
“I’d also like to take this opportunity to thank Matthew Wright for his leadership over the past six years, in which Southern Water has made a sustained improvement both operationally and financially as a result of his efforts.”