Pre-tax profits at Thames Water decreased by £9.5 million in the first half of its financial year.

The utilities firm, which covers Dartford and villages near Sevenoaks, watched its bottom line fall to £205.2 million in the six months to September, compared to £214.7 million in the same period last year.

The firm said it had reduced its bad debt and increased its dividends to £25 million from £20 million, which it paid to its parent company Kemble Water Holdings Ltd to services the debt.

It said there had been a 17% reduction in written complaints and had halved the number of pollution incidents.

Chief executive Martin Baggs said: “We continue to make significant strides in improving service, with customer satisfaction scores increasing and written complaints falling dramatically – a testimony to the fantastic work performed by our customer-facing teams.”