A protest camp was established at Harvil Road in the Colne Valley Regional Park in 2017, by environmental activists intending to protect the wildlife habitats of bats and owls. The protesters claimed that fresh water aquifer would be affected by HS2 construction works and this would impact London's water supply. The camp was populated by individuals including members of the Green Party and Extinction Rebellion. In January 2020, HS2 bailiffs began to evict the site after HS2 has exercised the right to compulsory purchase the land from Hillingdon council, which had not been prepared to sell the land otherwise. A prosecution of two activists accused of aggravated trespass had previously collapsed in 2019 when HS2 was unable to prove it owned the land the activists were allegedly trespassing upon.