2016-07-18 General Committee Meeting - Item 3 - Attachment 1 - Flood Management Plan

  Glossary
                     A F T
                  DR
These definitions are taken from within this document and
from the Queensland Floods Commission of Inquiry Final
Report Queensland Floods (2012)

Annual Exceedance Probability (AEP) means the
chance of a flood of a given or larger size occurring in any
                                                                Defined flood event (DFE) is the flood event adopted by
                                                                a local government for the management of development in
                                                                a particular locality.

                                                                Defined flood level (DFL) is the level of a flood that
                                                                would occur during a defined flood event (DFE).
one year, usually expressed as a percentage. For example,
if a peak flood discharge of 500m3/s has an AEP of 5%,          Flood map is a map which depicts the extent of a
it means that there is a 5% chance (1 in 20 chance) of a        particular flood or floods, for example the 1% AEP flood
500m3/s or larger event occurring in any one year (see          or a historical flood.
ARI).
                                                                Flood study is a scientific investigation into flooding in a
Australian Height Datum (AHD) means a common                    particular area, usually the catchment of a river system. It
national surface level datum approximately corresponding        may involve hydrologic and hydraulic investigations and a
ton mean sea level.                                             statistical analysis of the frequency with which floods have
                                                                occurred in the past.
Average Recurrence Interval (ARI) means the long
term average number of years between the occurrence             Flow velocity means the flow rate of water over an area
of a flood as big as, or larger than, the selected event. For   and is measured in cubic metres per second (m3/s) or
example, floods with a discharge as great as, or greater        cumecs.
than, the 20 year ARI flood event will occur on average
                                                                Hydraulic studies/investigations (with respect
once every 20 years. ARI is another way of expressing the
                                                                to flood studies) means an analysis that estimates the
likelihood of occurrence of a flood event (see AEP).
                                                                behaviour of flood flow (that is, flow rate, velocity, depth
Building controls are standards that regulate the               and extent of inundation) as it passes through a floodplain
construction of buildings, as distinct from planning            (see flood study).
controls that regulate where buildings are constructed.
                                                                Hydrologic model (runoff routing model) uses rainfall
These standards can be found in the Building Code of
                                                                data and estimates of the proportion of the rainfall which
Australia and the Queensland Development Code, or in
                                                                turns into runoff and the time which the runoff from each
planning instruments.
                                                                part of the catchment takes to flow into the stream to
                                                                estimate flow in the stream over time.




                                                                                    Noosa Council | Flood Management Plan | Page 39