Messinger has gone on to become chief executive of the Institution of Occupational Safety and Health, a post she will take up on 3 October.
Prior to joining Ofwat, Messinger ran her own management consultancy, after a local government career spanning over 30 years.
She has also been chair of Coventry Citizens Advice Bureau and trustee of KeyRing, a charity supporting people with learning disabilities. She is currently a non-executive director for Northamptonshire Healthcare Foundation Trust.
Ofwat chief executive Cathryn Ross announced plans last September to overhaul the regulator’s senior management team in preparation for PR19, which resulted in the loss of two roles – chief regulation officer and senior director of finance – and the creation of four new roles.
Messinger, formerly senior director of operations, immediately took on the new role of senior director of business improvement.
The new role of senior director for Thames Tideway was filled by Keith Mason, formerly director of finance and networks, in December last year.
The overhaul also saw the departure of former chief regulation office, Sonia Brown, the previous month.
Ofwat is now going through the recruitment process for a new senior director of business improvement.