Warning over water leak's impact on forest river

A large water leak in the New Forest could have a "severe" impact on sensitive habitats, conservationists have warned.

A burst main near the A35 outside Lyndhurst on Wednesday sent tens of thousands of litres of chlorinated water into the headwaters of the Beaulieu River.

Prof Russell Wynn, of the New Forest Biodiversity Forum, said the ecological impact of mains water entering the river could be "just as bad" as untreated water.

Southern Water said quality samples taken at the burst point indicated normal chlorine levels.

The New Forest Biodiversity Forum said it had led to about 2.5m litres of water - the equivalent of an Olympic-size swimming pool - leaking into the River Beaulieu.

Traffic restrictions were put in place on the A35 while work was carried out to repair the leak, which had caused water to flow onto the road and cycle path.

The forum said initial testing had shown a rise in chlorine and nitrate levels and there had also been a "strong smell of chlorine".

"It is too early to confirm the ecological impacts of this incident, but they are likely to be severe," it said.

The burst pipe was located between Lyndhurst Golf Club and Lyndhurst Wastewater Treatment Works.

After rising near Lyndhurst, the river flows south-easterly across the across the New Forest for some 12 miles (20km).

With water levels still low from the summer drought conditions, any substance entering the river is more concentrated and has the potential to cause more harm.

Conservationists say treated tap water – at the levels seen – can upset the delicate balance.

Species such as brown trout in the River Beaulieu are seen as particularly vulnerable.

Prof Wynn said: "If it is mains water, you could argue 'that's fine, it's treated', but unfortunately its full of chlorine, full of nitrate and that's almost just as bad for aquatic life sometimes as untreated water.

"Chlorine can interact with organic matter in the river and that creates inorganic compounds which are harmful to aquatic life, so in the round, we don't know what the ecological impact will be, but it's not looking very good."

Local environmental groups have taken their own samples of the spill, with results expected within days.

Southern Water said: "The leak has been stopped and a full repair is currently underway. All customers remain in supply.

"As part of our response, water quality samples have been taken at the burst point and initial results indicate normal chlorine levels."