18.—(1) The following provisions apply for the protection of the Agency unless otherwise agreed in writing between the undertaker and the Agency.
(2) In this Part of the Schedule—
“the Agency” means the Environment Agency;
“emergency” means a situation which—
is unexpected, in that there is little or no warning, or aspects of the event could not have reasonably been predicted in advance;
is a serious event presenting a risk of harm or damage to people, property or the environment; and
requires a need for urgent action, in that immediate action is required to address the risk of harm, repair or prevent a worsening of the situation; and
“relevant watercourse” has the same meaning as in article 23(4) (powers in relation to relevant watercourses).