In July, Southern was handed a £90m fine after pumping 16bn-21bn litres of untreated sewage into delicate ecosystems over a six-year period from 2010.
However, according to the company's newly-appointed chief customer officer, water complaints have fallen by 37 per cent in the year to April 2021 — which has 'heartened' staff.
"We recognise our waste water complaints and first contact resolution still have a long way to go to meet our customers’ expectations and we are determined to keep improving," said Katy Taylor.
“We have committed to resolve more complaints effectively the first time we receive them, reducing complaint escalations by 20 per cent by next year."
Ms Taylor said this will be done through improved training, 'more customer-focused resources' across the business and integrating systems.
She added: "This week I have hosted a conference to underline the importance of putting our custom terms at the heart of what we do every day which is an important and positive step forward.
“We know our customers want us to provide a reliable service to them and protect the environment with all we do.
"We are improving our use of sensors and analytics to predict and give early warning of blockage and potential flooding and pollution incidents.
"This will help us deliver on our commitment to reduce pollution incidents by more than half by 2025.”