A spokesman for Ravensdown said it has 6500 tonnes of waste on site that needs to be disposed of. “Options are severely limited and like just about every other business in Canterbury with demolition or excavation waste, Kate Valley is the facility that is top of the list.” Kate Valley is a 10-minute drive from Waipara in North Canterbury, and is a fully-consented landfill built on siltstone, which can help stop leaching. SUPPLIED An aerial view of the South Island's biggest landfill - Kate Valley in North Canterbury. Ravensdown’s spokesman said the waste came from a recent excavation project, when the company built three ponds on its Hornby site to improve water quality, and stormwater management.