11.—(1) Subject to paragraphs (2) and (3), a flood hazard map (or more than one such map taken together) shall show—
(a)the geographical areas which could be flooded according to the following scenarios—
(i)floods with a low probability (or extreme event scenarios);
(ii)floods with a medium probability (likely return period of 100 years or more); and
(iii)floods with a high probability; and
(b)the following elements for each of those scenarios—
(i)the flood extent;
(ii)water depths or water level, whichever is appropriate; and
(iii)where appropriate, the flow velocity or the relevant water flow.
(2) But a flood hazard map need not show information referred to in paragraph (1) as respects a flood with a high probability where the Department considers such a flood would be unlikely to have significant adverse consequences for the area which could be flooded by it.
(3) The Department may decide that for a coastal area which, in its opinion, is adequately protected from coastal floods, the preparation of a flood hazard map (or more than one such map taken together) may be limited to the scenario referred to in paragraph (1)(a)(i).