Appendix F - River Control and Drainage Works Programme Appendix F River Control and Drainage Works Programme 1. Introduction This appendix details the river control and drainage channel works permitted in Rule 27.1.8.1 (General Rules) of this Plan and for River Control Works which are designated and listed in Appendix B. This document updates the Wairau River Floodways Management Plan (1994) Sections D, F & G to allow for the river works that have been carried out and other changes that have occurred over the last three years. This document also incorporates works now proposed on small rivers and drainage channels. The River Control Programme deals with the Wairau River, its tributaries, distributaries and floodways; and the Drainage Works Programme with channels and small rivers in the Rural 3 Zone. Discussion of the issues and the reasons for the river works and drainage methods are not repeated in this document. 2. Priority of Works The higher priority works detailed in the Wairau River Floodways Management Plan have now been virtually completed. The need to specify a priority order for carrying out the further river works required is now much less of an issue. This document therefore does not specify a priority order, though the order of doing works will continue to be a blend of current standard of protection, engineering practicality and consequences of failure. 3. Wairau Floodplain Definition The Wairau River Floodways Management Plan divided the river systems into two separate zones; the Wairau floodplain zone and tributaries outside the floodplain. The standard of works and method of funding was different for the two zones. This is continued in the Wairau/Awatere Resource Management Plan. The Wairau floodplain downstream of the Waihopai confluence is a contiguous system of interlocking rivers, diversions and floodways, from which flood breakout is prevented by stopbanks. For this area a standard of flood protection for floods up to a 100 year return period flood is specified, unless impractical to achieve. This Wairau floodplain generally follows that of the Rural 3 zoning. The difference is approximately 3500 ha of land in the Rural 3 Zone to the south of the road line New Renwick Road/Dog Point Road/Hawkesbury Road/SH 63 which is not part of the Wairau floodplain. This area does not have a stopbanking system on its rivers and currently it is not economic or practical to provide a one in 100 year flood protection standard here. App F - 1