This is the latest phase in creating a dedicated 3,200sq m nature area. Timber decking pathways will surround the ponds to give visitors full access to the water and damp meadow habitats.
A wooden "dipping" platform will be built to allow school children to take part in pond-dipping and learn about the variety of animals that live in the water.
The £125,000 scheme, which is due to be completed by the end of the summer, is being jointly funded by the council, the Government's Playbuilder programme, Marks & Spencer and the SITA Trust, which supports environmental and community projects.
Paddington Recreation Ground is Westminster's largest open space, occupying an 11ha site in Maida Vale, and was first used for recreational purposes in 1860.