Ofwat is investigating how waste water and sewage networks are managed across the industry.
Severn Trent was the eighth case completed in its industry-wide wastewater investigation, which resulted in fines and enforcement packages of more than £300m, including a £104.5m fine for Thames Water.
But Ofwat said that unlike the seven previous cases, Severn Trent “proactively identified problems in its network” and “began to fix them” before the enforcement case was opened.
A spokesperson said, “Ofwat has formally accepted an enforceable package of undertakings from Severn Trent Water to ensure that the company returns to compliance.”
Severn Trent, which covers most of the West Midlands including Staffordshire, Shropshire, Warwickshire and Worcestershire and parts of the East Midlands including Derbyshire, Leicestershire and Nottinghamshire, said work was continuing to reduce leaks.
James Jasic, chief executive of the company, said: “We accept Ofwat’s findings relating to issues which we proactively identified and began addressing before the enforcement case was opened.
“Our investment program in spread reduction continues to accelerate across our region with the strength of our entire organization and supply chain behind it.”