Activity Group: Flood Protection and Control Works Floodway Reserves The total asset value for the Flood Protection and Control Works Activity as at 30 June To allow Council owned floodway land to have secondary uses of public 2017 was $200.7 million. access/recreation, ecological/amenity plantings, or for economic gain by forestry or Major Budgeted Capital Projects pastoral leasing as appropriate. The following table outlines the major budgeted projects and areas of expenditure Flood Hazard and River Management Advice proposed for this Activity over the next 10 years. Although these items are budgeted, in To provide flood hazard advice to other sections of Council for Land Information some cases further public consultation will be required with the relevant community Memorandum (LIM) and Project Information Memorandum (PIM) documents, and for before the project is implemented. These projects are also listed under the Capital resource consents, building consents and completion of the Proposed Marlborough Expenditure line of the Funding Impact Statement at the end of this Activity section. Environment Plan. The section also provides direct advice to landowners on flooding Major Capital Projects Inflated value and erosion risks, and mitigation options. Areas (Millions) Flood Response Wairau floodplain to 2018-28 Flood protection and control works $17.8 To monitor key river systems during a flood event, provide advice and undertake the Waihopai emergency repairs as appropriate. Advice of potential flood danger is provided to the confluence public and public agencies such as the Police and Civil Defence. 2018-28 Pump station and drainage network Wairau upgrades, excluding town branch drain $3.9 Asset Description floodplain $7.2 2018-23 Town branch drain upgrades The table below provides an overview of Council’s Flood Protection and Control Works assets. Emerging Issues and Expected Changes Asset Length /Quantity Taylor Dam Upgrades to Meet New Dam Safety Regulations Stopbanks, training banks, the Taylor Dam, and other minor The Taylor flood detention dam is now close to 50 years old and is generally in very dams which in total comprise of 4.8 million cubic metres of 180 km good condition. However, a comprehensive safety review completed earlier this year earthworks. has identified a number of matters for Council to attend to, including a minor capacity upgrade to the auxiliary spillway, installation of additional drainage and crest level Large rock rip rap for river bank erosion protection purposes. 585,000 m³ monitoring points, and resealing of the main outlet culvert joints. This work is Trees (willows, poplars etc) for riverbank erosion protection underway. purposes. 55 hectares Excavated minor watercourses for agricultural drainage and Similar refurbishment work is also required on the Gibson’s Creek Waihopai intakes. urban stormwater disposal purposes. 160 km Major river diversions. 4 Maintaining the Wairau River Alignment and Stopbank Security The stopbanked reach of the Wairau River downstream from the Waihopai confluence Pumping stations for agricultural drainage purposes. 19 has very powerful and erosive river flows. Bank protection in the form of rock rip-rap Pumping stations for urban stormwater disposal purposes. 11 armouring and tree planting is required to protect the stopbanks from erosion, Culverts under stopbanks etc of various sizes and lengths, especially as a result of floods. usually floodgated. 290 Regular asset inspections have confirmed the need for continued investment in new Control gates or weirs. 20 works and regular maintenance of existing works to ensure a robust flood protection Floodway land. 3,000 hectares system is in place. The main change for this plan is that new rock work has been identified as being required in both the lower Wairau and the Diversion reaches. Provision has been made for this work. 2018-2028 Long Term Plan Page 75