11.4 Flooding
11.4.1 Design Floor Levels
In ponding areas within the Waihou River flood plains, at least 80% of the area of the property shall have ground levels 200mm above the design flood level and the building floor levels must be 500mm above the design flood level, i.e. 300mm above ground level. Design flood levels are usually based on the risk factor of 1% annual return period flood event.
11.4.2 Design Standards for Buildings Subject to Overland Flow Paths
Buildings subject to overland flow from tributary streams shall meet the following standards:
- Exterior walls should be waterproofed.
- Large openings to the building should be located away from flowpaths.
- Minimum floor levels of habitable rooms shall be 500mm above general ground level or above stopbank crest levels or road formation levels.
11.4.3 Stormwater Flows
Where activities involve the development of large impermeable surfaces including buildings, structures and paved surfaces (exceeding a combined site coverage of 1,000m2), Council will require technical evaluations of the existing and anticipated stormwater flows and the necessity or otherwise of retention ponds or other stormwater control and/or mitigation devices.
11.4.4 Stormwater design
Detailed stormwater design shall be in accordance with the MPDC Development Manual 2010.
