SCHEDULE 11  FOR THE PROTECTION OF THE ENVIRONMENT AGENCY  Article 56  1. —(1) The following provisions of this Schedule, unless otherwise agreed in writing between  the Authority and the Agency, have effect.  (2) In this Schedule—  “the Agency” means the Environment Agency;  “construction” includes execution, placing, altering, replacing, relaying and removal and  “construct” and “constructed” are construed accordingly;  “drainage work” means any watercourse and includes any land which provides or is expected  to provide flood storage capacity for any watercourse and any bank, wall, embankment or  other structure, or any appliance, constructed or used for land drainage, flood defence or tidal  monitoring;  “plans” includes sections, drawings, specifications and method statements;  “specified work” means so much of any work or operation authorised by this Order as is in,  on, under, over or within 9 metres of a drainage work or is otherwise likely to—  “watercourse” includes all rivers, streams, ditches, drains, culverts, dykes, sluices, sewers and  passages through which water flows (whether or not the flow is intermittent) except a public  sewer or drain.  2. —(1) Before beginning to construct any specified work, the Authority must submit to the  Agency plans of the specified work and such further particulars available to it as the Agency may  within 28 days of the submission of the plans reasonably require.  (2) Any such specified work must not be constructed except in accordance with such plans as  may be approved in writing by the Agency, or determined under paragraph 11.  (3) Any approval of the Agency required under this paragraph—  (4) The Agency must use its reasonable endeavours to respond to the submission of any plans  before the expiration of the period mentioned in sub-paragraph (3)(b).  3.  Without limitation on the scope of paragraph 2, the requirements which the Agency may  make under that paragraph include conditions requiring the Authority at its own expense to  construct such protective works, whether temporary or permanent, during the construction of the  specified works (including the provision of flood banks, walls or embankments or other new  works and the strengthening, repair or renewal of existing banks, walls or embankments) as are  reasonably necessary—  by reason of any specified work.  73 (a) affect any drainage work or the volumetric rate of flow of water in or flowing to or from  any drainage work; or  (b) affect the flow, purity or quality of water in any watercourse or ground water; and  (a) must not be unreasonably withheld;  (b) is deemed to have been given if it is neither given nor refused within 2 months of the  submission of the plans for approval and, in the case of a refusal, accompanied by a  statement of the grounds of refusal; and  (c) may be given subject to such reasonable requirements as the Agency may make for the  protection of any drainage work or for the protection of water resources, or for the  prevention of flooding or pollution or in the discharge of its environmental duties.  (a) to safeguard any drainage work against damage; or  (b) to secure that its efficiency for flood defence purposes is not impaired and that the risk of  flooding is not otherwise increased, 