Closing the gaps

Work to close the two remaining gaps in the secondary stopbanks system for the Ashley River/Rakahuri starts this month.

This work is the completion of the Ashley River/Rakahuri secondary stopbanks system, a project that provides significant benefit to Rangiora, and the wider district, in the form of a more resilient flood protection scheme.

Major roadworks will occur to raise sections of the road to the height of the existing stopbanks on Millton Avenue and Cones Road where the gaps are, and will require road closures.

What's happening and when? 

  • Stage 1: Millton Avenue will be closed between River Road and Cones Road from 30 July-15 October. A detour will be in place via Cones Road.
  • Stage 2: Cones Road will be closed between Taggart Earthmoving Landscape and Garden Supplies and Millton Avenue from 16 October-23 November. A detour will be in place via Millton Avenue.
  • A route from Rangiora to the bridge will remain open throughout the work period, with detours clearly signposted.
  • No work will start on Cones Road until the work on Millton Avenue is complete and the road is reopened.
  • There will be speed restrictions on the detour routes whilst the detours are in place, however the current speed limits will be reinstated on both Millton Avenue and Cones Road once the work is complete.
  • Access to the dog park, the BMX recreation area, Taggart Earthmoving Landscape and Garden Supplies and the Department of Conservation will still be available throughout the work.

Stage 1 - Raising of Millton Avenue

Stop banks Stage 1 Raising of Millton Ave-map

Stage 2 - Raising of Cones road

Stage 2 Raising of Cones Road

The history

  • This project relates to the construction of the secondary stopbanks built in the area referred to as ‘Breakbank’ on the south side of the Ashley River/Rakahuri, near the Rangiora traffic bridge and rail bridge.
  • Construction of the stopbanks was initially completed in two stages, between May 2013 and March 2015.  Stage 1 involved work located upstream of Millton Avenue, and Stage 2 covered the work located between Millton Avenue and the rail bridge.
  • The design for the secondary stopbanks is to cater for a 500m3/s breach of the primary stopbank system upstream of the traffic bridge.
  • The stopbank system provides significant benefit to Rangiora, and the wider district, in the form of a more resilient flood protection scheme. The last major flood which breached the primary stopbank at this location was in 1953, and significant growth has occurred on the floodplain since then, so this is a crucial part of the ongoing evolution of flood protection from the Ashley River.
Ashley river overflow at Rangiora bridge 1953
Ashley River
Flooding of the Ashley River