Section 22 – Flood hazard maps
69.This section sets out what flood hazard maps must show and what they can exclude. The section also allows information to be presented in a single map or through multiple maps.
70.Subsection (1) sets out what must be shown in flood hazard maps and implements Article 6.3 and 6.4 of the Directive. Paragraph (a) requires maps to show areas which could be flooded by low, medium and high probability floods and subsection (9) enables the Scottish Ministers to define those probabilities in subordinate legislation in terms of a return period (expressed as a number of years) or an annual probability of occurrence (expressed as a percentage). Paragraph (b) requires maps to show flood extent, depths or level and water flow for each of type of flood covered by paragraph (a). These elements largely duplicate Article 6.4 of the Directive. The Scottish Ministers may specify further elements to be shown in regulations.
71.Subsections (2) to (6) allow information about certain kinds of floods to be excluded in different circumstances. These optional exclusions are permitted under Articles 2 (floods from sewerage systems), 6.3 (high probability floods), 6.6 (floods in coastal areas) and 6.7 (floods from groundwater sources) of the Directive.
72.Subsection (2) allows information about high probability floods to be omitted from flood hazard maps where SEPA considers that the floods concerned would be unlikely to have significant adverse consequences for the area which could be flooded. Areas which may be unlikely to experience significant adverse consequences as a result of flooding may be unpopulated areas which are regularly flooded and where the land affected is of low agricultural value.
73.Subsections (3)(a) and (4) allow information about high and medium probability coastal floods to be omitted from flood hazard maps where SEPA considers that the coastal area concerned is adequately protected from such floods. SEPA can still choose to map high and medium probability coastal floods even if it considers that appropriate flood protection is in place. It can also be directed to do so by the Scottish Ministers. These provisions do not apply to low probability coastal floods so these must be mapped.
74.Subsections (3)(b) and (5) allow information about high and medium probability flooding from groundwater to be omitted from flood hazard maps if SEPA considers it appropriate to do so. SEPA can also be directed by the Scottish Ministers to include information about groundwater flooding. These provisions do not apply to low probability groundwater floods so these must be mapped.
75.Subsections (3)(c) and (6) allow information about floods from sewerage systems to be omitted from flood hazard maps. This information may be included where SEPA considers that it is practicable to map such floods and it must be included if the Scottish Ministers direct SEPA to include it. The opt-out applies to those floods from a sewerage system which otherwise would have to be mapped. Floods that are caused by a sewer being overloaded by higher than usual rainfall are covered by the Act.
76.Where information is omitted from a flood hazard map under subsections (2) to (6), subsection (7) requires SEPA to include a statement in the map, explaining that information has been omitted. This general statement will therefore set out what mapping opt-outs have been exercised and what information is not shown on any particular map.
77.Subsection (8) requires the Scottish Ministers to consult SEPA before giving a direction under subsections (4)(b), (5)(b) or (6)(b) to include information about coastal flooding, flooding from groundwater or flooding from sewerage systems in flood hazard maps.
