Infrastructure Strategy Rivers — Flood Protection Resource Management Act 1991 (RMA) also oblige councils to take a more active role in managing flood risks than was required under earlier legislation. For Marlborough to achieve its vision for the future the infrastructure must be sufficient and functioning at the same time as being achievable and sustainable with the New river control assets may be required for several reasons: resources available. - areas that would like to benefit from flood protection and are prepared to meet he Flood Protection Goals costs can request this service from the Council To maintain and upgrade the Lower Wairau River flood protection works to the 100 - land development increases the flood runoff from the land year ARI flood protection - increased awareness of flood risks as a result of climate change and/or better Complete a technical review of the Wairau River Floodway Management Plan taking hydrological flood records account of climate change and levels of service commencing in 2021. New standards for flood protection will be agreed & adopted in response to the review The long history of flood control and drainage on the lower Wairau floodplain initially had an emphasis on risk management and affordability. However, over recent years Introduction the issues involved in river control and drainage have become more complex. Much more regard must now be given to maintaining and enhancing ecological values to This chapter covers three activities: meet the requirements of the Resource Management Act (RMA), the National Policy Statement on Freshwater Management (NPSFM) and the New Zealand Coastal Policy controlling flood waters from major rivers Statement (NZCPS). - - management of drains and small streams which receive the stormwater flowing The Council is committed to maintaining high environmental standards for its flood from the urban stormwater network in Blenheim, Picton and other settlements protection activities, particularly as there are many valuable and sensitive ecological land drainage, which is the steady, longer term removal of water from low-lying sites in the region. Maintaining and enhancing riparian ecological habitats, including - whitebait spawning areas and bird nesting habitat, is also necessary. rural land. Since 2010 significant flood events have occurred in most of the region’s rivers and 1 Specific challenges streams including the Rai/Pelorus/Wakamarina catchments, outer Sounds catchments, 1.1 Levels of service and increasing demand for flood in the wider Picton/Waikawa/Koromiko area, Wither Hills and Southern valleys and the main Wairau River and lower Wairau floodplain. The existing flood systems have protection generally coped well with these events. 1:100 flood protection for the Wairau flood plain The Wairau floodplain’s major rivers and stop-banked floodways cover A thorough review was carried out through the Wairau Rivers Floodway Management 20,000 hectares of fertile land around Blenheim, and is the Council’s major river Plan in 1994. These floodways include the Wairau below Waihopai, Opawa River, control and drainage activity. A review of the Wairau flood protection and drainage Taylor River and Omaka River below Hawkesbury Bridge, Opawa, Riverlands Co-op works is scheduled for 2019 and this will take into account land use changes over the and others. With the benefit of 30 years of good flood flow records it was decided that past 25 years as well as the predicted impacts of climate change. a 1 in 100 year return period flood would be appropriate as the standard for all the main rivers of the Wairau floodplain. Expectations of higher standards for flood protection and environmental values As part of the 1994 review, it was accepted that Blenheim residents could not expect works to be carried out to protect them at the expense of those diverted flood waters There is a trend for ratepayers to expect that Council will provide a high standard of affecting other areas. It was also accepted that the protection of the surrounding areas flood control and drainage throughout Marlborough. The Building Act 2004 and the should be carried out concurrently with, or even ahead of, the work to protect Blenheim. 2018-2028 Long Term Plan Page 206