Subject to sub-paragraph (2), the authorised development must be carried out in accordance with the flood risk assessment or any update thereof approved by the Environment Agency, including the mitigation measures detailed in it, so that no part of the authorised development is predicted to result in any exceedance of the flood levels to properties and land shown in the flood risk assessment.

Sub-paragraph (1) does not apply in any circumstance where the undertaker proposes to carry out a part of the authorised development otherwise than in accordance with the flood risk assessment or demonstrates to the Environment Agency’s satisfaction, in consultation with the relevant lead local flood authority, that the part of the authorised development concerned would not result in an exceedance of the flood levels shown in the flood risk assessment.

The authorised development is not to commence until a programme outlining the intended schedule and phasing of works and mitigation of flood risk during construction has been submitted to and approved in writing by the Secretary of State, following consultation with the relevant planning authority, relevant lead local flood authority and the Environment Agency on matters related to their functions.

The authorised development must be carried out in accordance with the programme approved under sub-paragraph (3).