Southern Water has been praised for its “transformational impact” upon water quality within a popular wildlife site.

The River Len Local Nature Reserve in Maidstone has for many years been dogged by the stench of sewage due to surcharges of untreated waste from the pumped sewerage system that serves south Maidstone and runs across the site.

Southern Water has finally tackled the issue by installing new sealing plates on the manhole covers, relining pipes and adding a flue to vent gases and reduce pressure within the sewer.

Cllr Tony Harwood (Lib Dem), who is chairman of the nature reserve’s management committee, said: "The infrastructure improvements were all delivered in the last few weeks and already the impact has been transformational.

“No leaks or surcharging of sewage has been observed since - even during and after the recent heavy rainfall.

“The clarity of the river water and growth of aquatic vegetation within the nature reserve is already showing signs of recovery. "

And he added: "The stink that has hung over the nature reserve and the surrounding area for years has also all but disappeared."

He is now looking for more improvements to the River Len elsewhere.

He said: “Investment in infrastructure is key to tackling the recent decline in water quality and biodiversity along the River Len.

“An extensive reedbed filtration system is needed to supplement Southern Water's Harrietsham Wastewater Treatment Works.

“Highway and farm runoff should be captured in balancing ponds and ditches rather than discharged directly into the river and its tributaries, and trees and other natural vegetation cover should be increased along the course of the Len as a pollution buffer.

“Outmoded man-made barriers such as weirs and culverts should be removed and measures taken to keep surface water from roads and buildings out of Maidstone's sewers, such as diverting rainwater into sustainable drainage systems and rain gardens.”