Managing critical source areas in Kaikōura

The Kaikōura Plains Recovery Project team has been focused on helping local landowners manage their farms post-quake, to reduce the impacts of land-use on the environment.

After the 2016 North Canterbury earthquake a study was undertaken to assess the damage, habitat, and health of streams in Kaikōura’s Lyell Creek/Waikōau catchment.

Several critical source areas (CSAs) were identified during the study including newly created springs, bank slumping, erosion and 104 overland flow paths (OLFPs).

Kaikōura Plains Recovery Project (KPRP) Manager Jodie Hoggard says that that managing CSAs doesn’t need to be ‘rocket science’ and to start small.

“Getting in touch with your local Environment Canterbury office can be a good first step. There are lots of people there ready and willing to help you find good methods for protecting our precious wai (water),” she said.

CSAs impact on freshwater quality

CSAs and OLFPs can include pugged areas, raceways, stock crossings, and springs. They often form in low-lying parts of farms such as gullies.

They carry contaminants like nitrogen, phosphorus, and sediment, which impacts the water clarity, quality, and freshwater biodiversity values.

By managing CSAs well, sediment and nutrient loss can be reduced and water quality improved. It also helps landowners to meet Good Management Practice (GMP) and the conditions of their Farm Environment Plan (FEP).

KPRP worked with Environment Canterbury and local landowners on two demonstration sites to show how simple interventions like fencing and planting could mitigate the impacts of sedimentation and erosion.

Montegues wetland’s minimal intervention

This wetland located on a small sheep and beef farm on Kaikōura Flats contained CSA of around 1,800m2 and flows into Warrens Creek.

KPRP Manager Jodie Hoggard said that the first step was to remove stock and fence the area off to allow the area to regenerate.

“By removing stock, we saw a significant growth of cutty grass (Carex geminata) which provides great filtering qualities, stabilises banks, enhances biodiversity and mahinga kai values, and increases habitat for native bird and animal species,” she said.

Willow control was also carried out and regular water testing for nitrate, phosphate, sediment and E. coli was attempted, but results were inadequate due to drought conditions. Water testing gives a good picture of what is happening on your site.

Montegues wetland before minimal intervention.png

Montegues wetland before minimal intervention

Montegues wetland after minimal intervention.png

Montegues wetland after minimal intervention

Maghera Farm medium intervention

With a CSA of more than 3,500m2 on the dairy farm, Maghera farm was one of the most significant areas containing CSAs in the catchment. More than 10 CSAs were recorded in the area, sitting alongside 507 metres of spring fed stream flowing into Lyell Creek/Waikōau.

A community planting day was organised by Environment Canterbury and Fonterra and more than 600 metres of fencing was completed, with 500 sedges, shrubs and trees planted to improve water quality and biodiversity values in the area.

The Kaikōura Water Zone Committee provided $7,400 from its ‘on-the-ground actions for freshwater’ fund.

Maghera Farm before intervention - overland flow path

Maghera Farm before intervention - overland flow path

Maghera Farm after intervention - overland flow path

Maghera Farm after intervention - overland flow path

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