The Borrow Pits Legacy: How 30,000 Cubic Metres of London Clay Shaped the Heath

This geological feature focuses on the borrow pits excavated during the Ponds Project to source the 30,000m³ of London clay needed for dam raising. The article explains what borrow pits are – excavations left after material has been dug for building embankments – and how their use represented an innovative approach to sustainable construction. The piece traces the fate of these pits, how they were landscaped and planted, and explores the geological significance of London clay. It also touches on archaeological discoveries during excavation, including a famous Mark 3 Ford Cortina found on the bottom of one pond.