After the serious damage inflicted over Auckland Anniversary Weekend and by subsequent storms and cyclones, there are signs the Kaipara Hills and neighbouring areas are getting on with the recovery process, although much of the land will take years to repair.
The most immediate work has been to clear streams and rivers of branches and slash, remove broken fences, repair culverts and drains, and string hot wires to control livestock.
A couple of weeks ago more than 60 farmers and landowners gathered at the Ahuroa Hall, about 20km west of Warkworth, to hear a series of presentations designed to provide practical information on remediating land affected badly by the recent events. Beef + Lamb NZ’s Extension Manager for the Northern North Island, Katrina Stead, organised the programme, which was designed to advise on planning for both short-term recovery and long-term resilience.
The panel of five speakers was made up of John Ballinger from Northland Regional Council talking about the adverse effects of different soil types and sediment flows; Duncan Kervall, a soil scientist from Kaipara Moana Remediation (KMR) who spoke about planting the right sort of trees to minimise erosion and withstand extreme weather events; and NZ Forest Service’s Mark Forsyth, talking about the nuts and bolts of the Emissions Trading Scheme.
These speakers were all Northland based, while Auckland Council was not represented. KMR currently has 400 sediment reduction plans being developed throughout the district on a 50/50 shared cost basis involving central and local government and the landowner, as well as setting up trial forests to identify appropriate replanting programmes.
They were followed after the lunch break by soil experts Dr Ants Roberts from Ravensdown and Murray Lane from Ballance, who provided analysis of the recovery rate for the soil types across much of the Far North, how to measure the specific areas of land affected by slips using AI technology and the use of helicropping trials to plan seed sowing for best results without disturbing the soil. The scattering of manuka seeds on slip faces was also recommended as a way to get quick results in areas where nothing else would seed.
Roberts referred to the particularly unstable soil types in the area, made up of layers of sandstone, mudstone and sedimentary rock, so the sandstone doesn’t bind together and tree roots grow sideways not down, looking for nutrients. Water makes the ground so soggy, there is no retention from the weak soil.
Ahuroa farmer Glen Ashton asked the tree experts what planting could be done during the recovery period and questioned strongly why they recommend blocking the waterways, as in his opinion it is essential to allow main channels to remain clear, so the water can flow downhill. In his experience, if you block a creek, it just causes a problem for someone further up the hill. But careful planting of trees and wetlands combined with stream clearance can mitigate the amount of water escaping and causing flooding. A recent research study by Scion has shown 60% of the water which fell over Anniversary Weekend was absorbed by the local forests.
Ashton finishes beef cattle on about 800ha on which slips have taken out a relatively low percentage of the total despite the dramatic appearance of the affected land, though he said in places there are slumps where a whole paddock has shifted 2m sideways. But this is not a new phenomenon, because it has all happened in the past, and eventually the slips heal over. He said he is sceptical of listening to the academic theorists, believing firmly in the principle of local knowledge.
This view was reinforced by another local farmer and soil ecologist, Jo Ritchie, who would prefer to see farmer groups carry out a case study of damage recovery in the district, informed by the experience of local farmers as opposed to experts from outside the area.
Since 2010 Sue Meszaros and Karyn Maddren have owned a 68ha farm near Ahuroa, where they run Streamland Suffolks with 200 ewes, 80 rams and a few cows and goats. They bought the property because it had good infrastructure including a woolshed, good paddocks and 15ha of covenanted QE2 bush.
In 2017 they were winners in the Auckland section of the Ballance Farm Environment Awards. At the time the judges praised their commitment to stewardship of the land, particularly fencing off streams and riparian planting with buffer zones, and their strong relationships with community groups.
Their farm has suffered from a number of slips, which have seriously reduced their rotational grazing options, but the areas of native bush demonstrate their value in preventing further damage. As noted by the Ballance judges, they are firm believers in the importance of locals getting together to help each other.
When I visited them a volunteer from the Forest Bridge Trust, a local organisation focused on returning kiwi to the area, was helping them with clearing fallen trees and branches from creeks and the river. The Rural Support Trust has also provided amazing support.
Meszaros was less enthusiastic about the structure and contribution of KMR because of its bureaucratic structure, which apparently prevents it from funding a local catchment group, and its failure to contact the flagship farms which had been part of its predecessor, the voluntary Integrated Kaipara Harbour Management Group.
She also felt there was too much pressure from the forestry proponents at the field day to plant trees without mentioning mānuka, which is the easiest and cheapest option, especially when it is too soon to plant anything else.
There is clearly some good work happening to get Kaipara farms back on track, but there remains a huge amount to do and it seems logical to involve the locals who know the area without being too prescriptive and bureaucratic.
