Stormwater OSD Weir Construction – Northmead

Occupancy Certificate rejected by Certifier due to stormwater requirements not being met.

The premise was a newly built commercial development in Northmead with an onsite stormwater detention tank (OSD). The OSD was not built to the design plan which required the construction of a weir within the tank and so was not certified by the engineers. In order to obtain an occupancy certificate for the client’s development, Stormwater Sydney was brought in to get the OSD back to specification. The weir is used as the mechanism for slowing the rate of water runoff leaving the OSD tank through an outlet, in order to prevent flooding of public and council stormwater ways during rain events.

We confirmed the requirements of the engineers to the supplied design plans which contained the approved design specifications for the weir. We then constructed the weir as per the original design plans. We provided a certificate of compliance and works report to the Client which was then forwarded to both the Engineer and Certifier. The end result was that the stormwater component was recognised as compliant and the Occupancy Certificate was issued by the Certifier.

We are often requested to undertaken remediation works after other trades have not completed the work to the approved design. While it is best that the original trade completes the work, it is often outside their skill set. It is important prior to the commencement of any work that needs to be certified that the trades understand the approved design and work to provide this. Many trades accept a job and commence to do it “their way”, which might look good but is unlikely to gain acceptance by your Engineer or Certifier. If you struggle with builders or plumbers not completing your stormwater requirements or meeting design plans, contact Stormwater Sydney for fast and effective rectification to get your developments certified and to achieve occupancy.


Stormwater Sydney Provides Inspection, Cleaning, Maintenance, Repairs, Construction and Advisory on stormwater systems across Sydney, Ensuring compliance with Sydney standards and Council regulations.

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