Three new pools are being created in Tooting Bec Common for amphibians to breed.
The project was formed by Wandsworth Council, charity Froglife, Tooting Common Advisory Committee and the Friends of Tooting Common.
Work began on crafting the pools in the commons existing ecology pond on Monday.
Volunteers will help monitor the pools to see if they have been successful in improving the environment for wildlife.
The ponds are part of Froglife's Dragon Finder scheme, which aims to conserve London's amphibian and reptile population.
It will also be used to educate people on conservation issues and provide training in amphibian identification.
Funding was provided by the Heritage Lottery Fund and the Western Riverside Environmental Fund, which uses landfill credits to pay for improvements in the Western Riverside Waste Authority area.
Vanessa Barber, London Dragon Finder project manager, said: "We are thrilled to be working with Wandsworth Council to improve such a well known and loved site.
"And the physical improvements are just the start.
"Through our community training programme we hope to make these ponds a strong-hold for amphibians, reptiles and other wildlife for years to come."
For more information visit froglife.org/dragonfinder/app