The River Dour runs through Kearsney Abbey and is a rare habitat for flora and fauna, one of only 200 chalk streams in the world. Permeating through the chalk of the North Downs, the Dour has exceptional water quality along with a stable temperature that supports the most significant colony of brown trout in south east England. The name Kearsney is derived from the French cressonnière, a place where watercress grows.
The water quality of the River Dour is excellent due to natural filtering through the chalk beds of the Downs. This supports a rich mix of botanical and invertebrate life. Plants such as river water crowfoot and starworts can be seen mid-channel, whilst watercress and lesser water parsnip can be found along the margins, along with lush bankside vegetation. The stable flow and temperature of the River Dour also support notable fisheries, including a significant colony of brown trout. Pond dipping is a popular activity with children.