Conclusion 26

Major infrastructure programmes can also pose a threat to chalk streams and other delicate river environments. In the Chilterns, HS2 is likely to require over 10 million litres of water a day for its tunnelling operations. The Environment Agency told us that it will not give approval to any parts of HS2’s plans until they have identified and set out any potential groundwater impacts and agreed acceptable mitigation actions.54 49 Q 36 50 Q 37 51 Letter from Department to the Committee dated 15 June 2020 52 Qq 36, 40 53 Qq 40–41 54 Qq 42–43 Water supply and demand management 15