Engineers have agreed to build a dam around a neighbourhood pond after 600 fish, small animals and birds were killed by poisonous sewage.

Southern Water plans to use closed-circuit cameras to investigate a lethal dose of ammonia that swept through a lake in Farne Close, Hailsham, killing off wildlife.

The company said it will also hire a landscape specialist to help construct a weir and plant reed beds to protect the leafy enclave.

David Seaman, who owns the pond which links to the River Cuckmere, said it would take years and about £3,000 to restore it.

Danger signs now surround the small oasis, tucked behind a housing estate on a piece of scrubland, warning it has been polluted.

A duck gave birth to a dozen chicks on an island in the middle of the pond two days ago but Mr Seaman fears they may not survive.

He said: "The whole ecology has been upset over this, it's not just the fish but weeds and larvae.

"The chicks feed by skimming the water but because it's been so polluted they are now at risk."

Neighbour Paul Pandlebury said about 600 small fish, eels, frogs and birds were killed when rising sewage levels poisoned every living creature within 72 hours.

He said: "We got the Environmental Agency here and they found there was ammonia flowing into the pond.

"It's looking a little better and smelling a little better now but a lot of fish died. They may have been little but they were the basis of the food web.

"Without them nothing will live in the pond beyond microscopic organisms."

Southern Water said it will now place CCTV cameras inside the sewers to look for blockages and cracks.

It is thought some houses could have waste pipes illegally connected to a storm drain which flows into the pond.

When the water content of sources feeding the lake was measured ammonia levels were up by 27 per cent.

Mr Seaman said it had taken more than two years to stock the pond with fish swimming in from the link with the Cuckmere. Birds, bats, and all manner of wildlife followed.

Partially disabled following an industrial accident, he and neighbours began taking care of the pond after developers failed to get permission to fill and build on it.

But since the accident wildlife such as barn owls, a pair of kingfishers and a heron have all disappeared.

Mr Seaman said: "We found lots of dead blackbirds by the pond who had drunk the water and were poisoned.

"The heron who used to always be by the pond has now flown away and he won't be back because we haven't any food for him.

"Six years' worth of work has ended with the death of the fish. It's been a labour of love but to start it all over again is going to be a real struggle,"

said Mr Seaman, who suffers from impaired vision after a chemical accident.

Jim MacIntyre, waste water area manager for Southern Water, said: "Southern Water has been working very closely with Mr Seaman and the Environment Agency to assist with the return of the pond to its previous state."