The HB Regional Council has for seven years implemented an Erosion Control Scheme (ECS). Its goal is to reduce sediment loss to our waterways by 50% through planting one-third of the region’s most highly eroding land.

The only ‘criticism’ one might make of this programme is that it’s too small and slow.

Approximately 252,000 hectares of Hawke’s Bay hill country has been identified as being at high risk of erosion. Anthropogenic erosion contributes, on average, 3.27 million tonnes of sediment into the region’s waterways yearly.  That’s an average of 136,000 truck and trailer loads of sediment per year.

High levels of sediment affect the region’s water quality and aquatic habitats, as well as the biodiversity that depends upon them. Erosion on farmland also undermines current and future productivity. In 2008, hill country erosion was estimated to be costing New Zealand between $100 and $150 million per year annually.

Furthermore, this sediment doesn’t only wind up in waterways, something left out of much cost-benefit analysis. The HBRC team notes that “Cyclone Gabrielle deposited over 10 million, maybe closer to 20 million m3 on land. The cost to collect and safely manage that is estimated to be between $40-50 per cubic meter.” That’s $400 million at the low end.

According to HBRC, for much of our highly erodible land (i.e., land losing more than 1,000kg of sediment per hectare per year), sediment loss could be reduced by between 700 – 900kg per ha /yr. Effective interventions include sediment retention ponds, traps and bunds to manage surface erosion; buffer strips and cover crops to manage surface erosion; debris dams used to manage gully erosion; riparian fencing and/or planting to manage streambank erosion; and improved cultivation and grazing management.

To date HBRC has invested around $13.5 million toward the ECS. This has leveraged a further $10 million at least, toward planting and other related activities. The ECS co-funds erosion control where the cost of implementation outweighs the private benefit received by the landowner. HBRC’s Catchment Advisors have engaged with no less than 503 individual properties, covering roughly two thirds of the region’s farmland identified as highly erodible, resulting in the direct treatment of 5,075ha. But remember, that’s against 252,000ha (2%) of priority land … dare I say, barely scratching the surface?

Where to?

Soil erosion control must be made financially viable to the pastoral farmer. And HBRC says it can be.

The gestating HBRC Land for Life programme aims to recruit hundreds of farms over the next ten years into a more comprehensive pastoral land use scheme, still centred around prudent tree planting. The goal is to transition to a more carefully planned type of land care that is commercially sustainable on a farm-by-farm basis, an aspiration beyond the brief of present ECS subsidised programme. BayBuzz has reported on the Land for Life project here.

HBRC’s current Long Term Plan states that “by 2050 all highly erodible land will be under tree cover”. 

HBRC’s staff report realistically calls this: “A high-level aspirational statement that somewhat over-simplifies the issue and solution.” But goes on to say:  “However, the intended sediment reduction outcomes would still be achievable through the widescale adoption of soil conservation best practice on highly erodible land. This will require further targeted effort and investment, informed by robust land and freshwater science programmes.”   

Looking at the environmental and economic damage created by this magnitude of soil loss in the region, ECS and Land for Life cannot accelerate fast enough!