Infrastructure Climate Resilience Projects

In 2020, central government’s budget included $210 million for climate resilience and flood protection projects across New Zealand. This funding formed part of government’s response to the economic impacts of COVID-19. Horizons Regional Council received $26.9 million of this funding from Kānoa, the government’s Regional Economic Development & Investment Unit (REDIU). Horizons contribution to the four projects is an additional $9 million.  This collaborative funding has enabled Council to accelerate work on four Infrastructure Climate Resilience Projects, which were already planned or underway, to increase our river communities resilience to the effects of climate change.

The funding will also create new employment opportunities - we’ve conservatively estimated the number of jobs created as 36 across Horizons, external consultants and contractors. These projects will not only assist in keeping our communities safer but will help boost the region’s economy as work on maintaining and building new infrastructure progresses. The completion date for all four projects is March 2024.
 

Te Awahou Foxton Climate Resilience Project

In recent years Foxton has experienced flood events which have highlighted the inadequacy of the current drainage system.

Horizons and Horowhenua District Council have been responding jointly to this issue, with funding set aside in both councils’ current Long-term Plans. Kānoa-REDIU funding has enabled Horizons to explore options including a mitigation strategy which diverts water away from Foxton Township and stores it on rural land south of Foxton. The water will then either drain through gravity or be pumped back into the Foxton Loop.
 
Horizons has met with directly impacted landowners and is meeting regularly with local iwi to identify the impact of this work on taonga, whenua, and wahi tapu. Horizons has also invited the wider community to meet with them on a number of occasions to discuss the project at Te Awahou Nieuwe Stroom. 

The following list details the current proposed works for the project and aligns with the illustrated map below. 

  1. Upstream Attenuation – The FEDS channels are limited in their conveyance; therefore, it is necessary to slow design-flood waters down prior to entering FEDS main channels.  This can be accomplished through the use of existing dunes, bunding, and a control culvert.
  2. Channel Works – The channels throughout FEDS are in poor condition and require excavation of stable banks and an appropriate bed grade.
  3. Spring Street HDC Aligned Works – HDC’s long-term roading upgrade and development plans for Spring Street are still being decided.  It is important that any FEDS work in and around this area fit with HDC’s long-term plan.  This includes channel re-alignment, channel capacity upgrades and culvert upgrades. 
  4. Avenue Road Infrastructure – The downstream Spring Street stormwater reticulation network and culverts beneath Avenue Road are not matched in size and require upgrading to an appropriate size for design conditions.
  5. Kings Canal PE Sheetpiling – To ensure the true right bank of Kings Canal does not breach, private property impact is minimised, and travel time of ground water during storm events is reduced to an appropriate duration, PE sheet pile will be installed to a design depth and height.
  6. Cook Street Wetland – An excavated and planted wetland environment is planned at the eastern end of Cook Street to help improve FEDS water quality prior to its discharge into the Foxton Loop.
  7. Coley/Cook/Union Culverts – These culverts will be upgraded to appropriately sized box culverts to effectively convey design storm event.
  8. Stable Channel Works – Channels throughout FEDS will be modified where necessary to ensure bank failure and silt introduction to the waterway is mitigated.
  9. Purcell Street Penstock – A penstock gate is proposed at the upstream end of Purcell Street to allow closure of the FEDS channel along Purcell Street and redirection of flood waters towards Whirokino when required.
  10. FEDS Weir & Diversion – A diversion culvert is proposed at the upstream end of Purcell Street to allow flood waters to redirect towards Whirokino when the penstock is closed.  This culvert will also relieve localised flooding around the Ridge Road area.
  11. Channel Enhancements – An appropriately designed conveyance channel is proposed to mitigate flooding of farmland in the Whirokino area, East of SH1 and North of Newth Road from any redirected FEDS flood waters as well as local catchment flood waters.
  12. SH1 Flood Culvert – A new flood relief box culvert is proposed beneath SH1 to appropriately convey design flood event runoff from FEDS as well as help relieve local catchment flooding in the Whirokino area.
  13. Swan Lake Redirection – The channel that conveys discharge from an existing culvert beneath SH1 into Swan Lake is proposed to be redirected towards the Hokorawa / Duck Creek, which will help mitigate flood hazard along Stewart Street.
  14. Whirokino Drainage Improvements – The low lying land in Whirokino is proposed as a storage area for large flood event.  Stored water can then be pumped out of the Whirokino area and into the Moutoa area following a large storm event.  Some channel enhancements are proposed to ensure water is conveyed efficiently through the Whirokino area.
  15. Shared Pumping Station – A pumping station is proposed near the low lying land in Whirokino adjacent to the Moutoa stopbank.  This pump station will have combined service for both Moutoa and Whirokino.

Whirokino Wetland – A wetland is proposed within the Whirokino to treat the runoff before it enters the Foxton loop. The location of the wetland has not yet been finalised.
 

Te Awahou Foxton Climate Resilience Project - Illustrated Map

Te Awahou Foxton Climate Resilience Project - Factsheet

Foxton East Drainage Scheme Webinar

Lower Manawatū Scheme Climate Resilience Project

Horizons has been investing on behalf of ratepayers in increased flood protection standards for the Lower Manawatū area since 2006, as a result of the impacts of the devastating 2004 floods. This has included raising/rebuilding stopbanks, replacing the Kopane Bridge and constructing the Burkes Pump Station.
 
Following the injection of additional funding from Kānoa-REDIU, the Lower Manawatū scheme (LMS) resilience project was established. This project includes further strengthening of the stopbank network and building resilience at key locations. This project is anticipated to take three years and will create local employment opportunities.
 
The LMS resilience project encompasses several sub projects along the Lower Manawatū Scheme. Work is currently underway for flood mitigation and general maintenance along the Hartley Street sea wall in Foxton. This includes restoration of the existing rock armouring with new natural rock. Similar work is planned for Te Matai Road, Palmerston North. Work is also in the planning stage for upgrading the Moutoa floodway outlet (Piri Harakeke). This will be jointly undertaken with the Foxton East flood mitigation project.
 

This photograph shows the degraded Hartley Street sea wall, Foxton Beach prior to Horizons carrying out maintenance work.  The end result of this work will be a more attractive, naturally lined rock wall that provides additional protection to nearby homes and recreational walkway.
 
 
 

 

Palmerston North Climate Resilience Project

The scope of the Palmerston North flood protection resilience project work includes upgrades to flood defences (primarily stopbanks) and the replacement of a number of aging assets, along with new work which will include additional amenities, such as pathways and signage, and enhancing public access to the Manawatū River and Mangaone Stream.

One of the key enhancement projects Horizons is working on, in consultation with Rangitāne and Palmerston North City Council, is upgrading the area around the northern end of the Manawatū River bridle path. Plans include changing the current shady and often damp area to a river access path with bright open spaces, riparian planting, artwork and signage identifying the significance of the site. This work began in July 2021, with removal of some of the poplar trees currently shading the site.

Along the Mangaone Stream several pieces of ageing infrastructure are also being upgraded – from below Flyers Line to the confluence of the Manawatū River. Work will include realigning a section of the Mangaone Stream stopbank near Pioneer Highway.

Palmerston North Climate Resilience Project factsheet

This rig is being used to conduct cone penetration testing (CPT), an in-situ test that is used to identify soil types, on the stopbanks of the Manawatū River and Managaone Stream. In this test, a cone penetrometer is pushed into the ground at a standard rate and data is recorded at regular intervals during penetration. This gives us important information about the composition of the stopbank and also the ground the stopbank is built on, identifying areas where further river management work is required.

Work started in July 2021 to remove some of the poplar trees currently shading the site at the northern end of the Manawatū River bridle path.

 

Rangitīkei River Climate Resilience Project

We are currently developing a new management strategy for the Rangitīkei River that recognises the dynamic nature of the river. The intention is to moves towards a more resilient river system that has ‘more room’ while accommodating goals of greater river character, greater river biodiversity, and enhanced public access and recreational opportunity.
 
This project focuses on only the Lower Rangitīkei River from Bulls to the sea and includes:
 
•    Addressing the risk of river avulsion against the Parewanui Stopbank through channel widening activities such
     as removing non-native vegetation mechanically, and aerial spraying and gravel management which creates
     multiple river channel options;
•    Slowly transitioning pastoral land into a continuous native plant corridor alongside the river;
•    Flood resilience work - for example the Scotts Ferry Rock Lining Repair;
•    Wetland options along the Parewanui No.1. Drain; and
•    The creation of pathways for recreational use along some parts of the stopbank
 
The project is intended to have positive environmental and social outcomes for the Rangitīkei River and its users.
 

Rangitīkei River Climate Resilience Project factsheet

Horizons staff are currently working with Ngā Wairiki Ngāti Apa on enhancement of the Tutaenui Stream at the confluence with the Rangitītikei River as part of the Lower Rangitītikei Enhancement Project. Exotic tree clearance and clearing channel blockage work began in June this year and fencing along the stream is expected to start in September. Riparian planting will start next year.

October 2021 - Rock diverted for Rangitīkei River emergency works
 During Level 4 lock down a couple of small flood events eroded the right bank of the Rangitīkei River near Burns Ford Road. Emergency repairs are now being carried out to protect the base of the stopbank and prevent further damage occurring. To achieve this, rock intended for the repair work to existing rock lining of the Rangitīkei River at Scotts Ferry, has been diverted to the emergency works. Further rock has been ordered for Scotts Ferry and work on the rock lining will recommence early in 2022.
 
This work is part of the Lower Rangitīkei Enhancement Project which is funded by Kānoa, the government’s Regional Economic Development & Investment Unit, and managed by Horizons Regional Council.
 
This rock diversion is not expected to delay the December completion of the Parawanui stopbank at Scotts Ferry.
 

November 2021 - Flood Resilience improvement for Tangimoana Beach road
 An addition to the Rangitīkei River stopbank is to be built across the Tangimoana Beach Road. It will join up on both sides with the current stopbank and will make the area more resilient to flooding by raising the road to stopbank height. Currently, when the flood action plan is triggered for the Rangitīkei River, flood gates are transported from Marton and installed on the Tangimoana Beach Road. This is a logistics nightmare and would not be possible if the river breached its’ banks at Bulls.
 
Work will commence in late November 2021 and is expected to be completed by Christmas. The road will be closed at times and traffic management will be in place for the duration of the work.
 
This road is the only access to the Tangimoana boat ramp so please keep any eye out for Downer NZ signage regarding road closures.
 
This work is part of the Lower Rangitīkei Enhancement Project which is funded by Kānoa, the government’s Regional Economic Development & Investment Unit, and managed by Horizons Regional Council.