Attachment I - Flood Assessment

Cooroy Hinterland Park Flood Assessment



6 SAFETY AND MAINTENANCE ASPECTS

6.1       Safety
Council’s modelling predicts that the site will be subject to Cooroy Creek flood inundation during
events as frequent as the 50% AEP (similar to a Q2 event). Safety and on-going maintenance
issues therefore need to be carefully considered.

During times of flooding most areas of the Hinterland Park will not be safe for use. Furthermore, it
is noted that Cooroy Creek has a relatively short response time meaning that flooding may occur
without much warning. Therefore, measures should be put in place to minimise risk to personal
safety. HWMC recommend that consideration be given to the following measures to reduce these
risks.

      •    Clear warning signs should be incorporated across the site to educate the community on
           flood risks.
      •    The design of the park should aim to limit potential for users to become trapped on-site
           during times of flooding. Elevated walkways that are easily accessible may be a good
           option for this, particularly to allow access across the central drain through the site.
      •    Closing the park when floods are forecast to occur is recommended however it is noted
           that some floods are likely to occur with little warning time and therefore this may not
           always be possible.
      •    The nature theme of the park is considered to provide an opportunity to educate users
           about flood risks in general and also about risks specific to this location. Consideration
           should be given to incorporating a landscape feature that highlights flood levels that have
           occurred on site during historic events.


The above measures are expected to reduce the exposure of flood risk to users of the park.
Despite this, Council should understand that a residual risk will remain because ultimately the park
encourages the community to congregate in an area with a known risk of flooding.



6.2       Maintenance and Flood Resilient Design
The park is expected to be subject to a relatively high frequency of flood inundation and therefore
it should be designed to be flood resilient.

      •    It should be constructed out of materials that will not be damaged by flood water and can
           be easily washed down following a flood.
      •    Use of landscaping materials that will be mobilised during floods should be avoided.
      •    Any features of the park that are less resilient to flooding should be constructed on land
           that is above the design flood levels described on Image 3-2.




J00318R1V1                                                                                          11