Writing in the annual report, new chairman Richard Parry-Jones said customer satisfaction levels continued to rise and pollution incidents continued to fall and the utility generated more renewable energy than ever before.
However, he warned that net profits have been hit by an increase in interest costs. Yorkshire Water had net debts of £4.49bn at the year ending March 2015.
At the start of the new financial year, ratings agency Moody’s downgraded Yorkshire Water over concerns about its £2bn portfolio of derivatives.
The company put the inflation-linked swaps in place in 2008 when its parent Kelda Group was taken over by a consortium of international investors.
But the subsequent fall in interest rates in response to the global financial crisis led to a collapse in the market value of the portfolio.
Mr Parry-Jones said: “Our treasury team is focused on managing the impact of the derivatives success in renegotiating terms.”
Yorkshire Water said its plans to invest £3.8bn in Yorkshire over the next five years but must focus on delivering “more for less” with bills due to fall by an average of 3 per cent in real terms by 2020.
Mr Parry-Jones said: “This is good news for our customers and will ensure that their bills remain one of the lowest in the UK, however this does put a challenge on business performance.”
Yorkshire Water revealed it paid corporation tax of £13.6m last year, compared to a credit of £60.9m the previous year. Operating profits rose six per cent to £350m.
Chief executive Richard Flint’s total emoluments and pension-related benefits were £1.475m.
Mr Parry-Jones paid tribute to former chairman and CEO Kevin Whiteman, who he replaced in March.