CODE OF PRACTICE FOR SUBDIVISION AND DEVELOPMENT

Part 4 – DrainageWhere open watercourses are to form part of the land drainage system this shall bedetermined at scheme plan approval stage, and the developer shall submit sufficientengineering design to enable Council to evaluate the proposals.Each lot on the development shall be served by a storm water connection located withinthe main body of the lot.Each storm water connection shall be capable of serving the whole of the building area ofthe lot by gravity from a ground level discharge, except where this requirement seemsunreasonable and it can be shown that the proposed connection is adequate for apredetermined building location.The storm water connection will be to a piped public storm water system or where theground conditions are suitable and subject to the prior approval of the Engineer, a systemthat partially disposes of storm water by soakage into the ground may be permitted.Where further development, upstream of the one under consideration, is provided for inthe District or Regional Plans, the Engineer will require storm water pipelines to beconstructed to the upper limits of the development.Where the Council has a Catchment Management Plan prepared for the catchment,whether it has been formally issued by the Regional Council or not, the recommendationscontained within the Management Plan shall be followed. This includes the recommendedrainfall intensity, runoff coefficients and discharge flows.Where no Catchment Management Plan exists the Council’s depth-duration-frequencycharts shall be used.4.2.6 Open WatercoursesMajor watercourses should preferably be retained, and be located together withsecondary 1% overload flow paths in public reserves.The extent of stream improvement work shall be agreed with the Engineer in order toachieve a satisfactory compromise between the retention of the natural topography andvegetation, maintenance, hydraulic and safety considerations, and the downstream effectsof the work.Riparian margins shall be planted with suitable plant species, subject to the prior approvalof Council’s Open Spaces Manager.Access to watercourses for maintenance shall be provided for by incorporating esplanadereserves or easements in the layout of the development. Accessways shall be a minimumof 3m wide, with gradients suitable for the passage of trucks and machinery.Code of Practice for Subdivision and Development – Edition 5 October 2010 Page 59