certification of a water management plan for a Construction Certificate

We are going through the construction certificate stage for a residential project in Sydney's upper north shore. The private certifiers request the proposed water management plan for the dwelling already approved and stamped by Council during the DA process be certified by a hydraulic engineer. There were a few amendments requested as per the DA conditions, which have been completed by a hydraulic consultant, but it still needs to be certified by a hydraulic engineer, plus another amended completed as pointed by the certifier. I attach all relevant documentation through the a link below, including the CAD file. Can you please provide a fee proposal at your earliest convenience? This is what the certifiers request for the current stormwater plan to be approved: "Condition 11 – The trenches have been relocated but not marked as cast iron. Also plan needs to be certified by a hydraulic engineer that it does meet this condition." This is the final step in what has been a very long process, so we would appreciate your prompt reply to whether you can complete this work. Maria The following documents are accessible via the link below: [login to view URL]!1299&authkey=!ACVeEJYpxBmyBr8&ithint=folder%2czip 1) DA 2) Architecturals 3) Amended Water Management Plan following DA conditions -- this would be the one requiring the amendment and certification/ stamping by a qualified hydraulic engineer 4) Original water management that was stamped by Council when we got the DA 5) Site plan/ survey 6) Revised landscape plan already approved by certifier. 6) Email we got from certifier last week explaining what is needed in the watermanagement --condition 11 for DA