2505-45871 SRA - SARA advice notice

                                                                                                       2505-45871 SRA



                       Drawing 2319-009, prepared by Callaghan and Toth Consulting Engineers, dated
                       April 2025, revision A) indicates the culverts would be at capacity at a 4EY event
                       and would overtop at a 2EY event. Such a design indicates that fish passage will be
                       impeded during events that can reasonably be expected several times a year. While
                       the submitted planning report states that ‘the culverts are likely to be overtopped 2
                       times per year’, it should be noted that overtopping is distinct from drownout1.
                       During times of overtopping, fish passage is likely to be restricted due to a drop in
                       water level over the structure when the headwater level is higher than the tailwater
                       level.
                      Design drawings depict smooth concrete aprons on both the downstream and
                       upstream ends of the culvert crossing. These aprons are likely to produce flow
                       conditions that would also cause a significant restriction on fish passage.
              Advice:
              Provide an amended design outcome to meet the relevant assessment benchmarks of
              SDAP State code 18. It is strongly recommended that an amended design consider:
                      at least one additional 1800mm culvert cell is provided. Providing the largest
                       possible aperture with roughening is best design for fish passage; and
                      roughening is provided on the aprons, e.g. using a rough broom finish, exposed
                       aggregate etc.


Please note that unlike an information request, assessment timeframes do not stop when advice
is provided by SARA.

How to respond
It is recommended that you address these issues promptly and provide a response to SARA.

If you decide not to respond, your application will be assessed and decided based on the information
provided to date.

Under the Development Assessment Rules (DA Rules), the issuing of advice does not stop the
assessment timeframes. If you intend to provide additional information, it should be provided in a timely
manner to allow sufficient time for the information to be considered. As such, you are strongly
encouraged to consider using the ‘stop the clock’ provisions under s32 of the DA rules, to allow sufficient
time for you to consider and respond to SARA’s advice; and for SARA to consider any new or changed
material provided.

If you wish to utilise the ‘stop the clock’ provisions, you should give notice to the assessing authority
(assessment manager or referral agency) whose current period you wish to stop. This can be done
through MyDAS2 or via correspondence.

You are requested to upload your response using the ‘manage documents’ function in MyDAS2.




1 drownout of the structure refers to when the headwater and tailwater levels are equal and covering the structure so

that fish passage is unrestricted over the top of the structure. This is not the same as when water begins to overtop
the structure.


 State Assessment and Referral Agency                                                                      Page 2 of 4