Southland Initiatives
Bruce Beckingsale, MAF Policy Agent, Invercargill
In Southland, a joint approach to environmental monitoring and research has been set up. It is based on a sub-catchment of the Mataura River, the Oteramika Stream. This catchment was selected because its outfall has been identified as high in nutrients and within the catchment is the Southland Dairy Co-op's factory and the Rayonier Tree Nursery at Edendale.
The catchment consists of about 6300 hectares and 150 properties.
Organisations involved in the monitoring include the Southland Regional Council, AgResearch, New Zealand Fertiliser Manufacturers Research Association, Southland District Council, DOC, Southern Health, Fish and Game Council, Landcare Research, Aqua Firma, the Oteramika Land Care Group, MAP Policy and Southfert.
Monitoring includes groundwater flows and quality; stream flows and water quality; soil characteristics including soil types, fertility levels and compaction; land use, agricultural inputs, agricultural production, effluent disposal systems, riparian management, water use; stream biota and fish life.
Information is to be loaded into the Basin New Zealand Model operated by Bruce Thorrold of AgResearch. Prom this, indicators of environmental sustain ability should be derived.
The project was initiated 12 months ago arid a lot of the monitoring is just getting underway or not yet started.
Additional Background Information
What is the Purpose of the Trial Catchment Study?
The purpose of the trial catchment study is to:
- Get to know really well the natural arid physical resources within a small rural catchment that contains a mixture of sheep, dairy, and crop farming activities. These include:
- soil, geology, vegetation, climate, land use type and distribution;
- land use practices and effects (e.g., stock type and densities, soil compaction, fertiliser application, effluent and waste disposal);
- surface and ground water quality, quantity, and their use by land owners (and industry);
- biological characteristics of surface waters (e.g., fish populations and their food source, weed growth etc.).
This information gathering exercise can be considered as the "Catchment Characterisation Phase". Data from it will be used to assess the current environmental status of the Oteramika catchment and be used as a benchmark to compare with information derived from future monitoring and manipulation of water and land use resources. It will also be used to accurately determine a contaminant budget for the catchment, where inputs into the catchment (e.g. k fertilisers) are compared with exports from the catchment (e.g., produce, nutrients and sediment in water, etc.). Catchment contamination budgets would help assess whether land use practices in the Oteramika are sustainable.
2 Implement resource monitoring programmes and associated trial manipulations of land and water resources, with the co-operation of landowners, to determine the effects of individual land use activities on surface and ground waters.
When we talk about trial manipulations of land and water resources, we mean things like:
- experimenting with riparian plantings along stream margins to determine their effects on bank stability, lowering water temperature, weed growth, nutrient levels in surface and ground waters, sediment losses from land to water, and fish distribution;
- land disposal of effluent - comparing different application rates on pasture growth, ground water contamination, application to wood lots;
- determining the effects of different farming practices (e.g., dairy versus sheep grazing, different fertiliser applications) on nutrient leaching through the soil profile.
As well as monitoring the above trials, other more general long-term monitoring programmes could include:
- land use activities (general trends in farming practices);
- nitrogen levels in groundwater (monitoring is already occurring in some parts of the catchment);
- other contaminants of groundwater (e.g., human pathogens, pesticides, phosphorus);
- groundwater supply (is this resource becoming vulnerable as more users draw on it?);
- general surface water quality and quantity (particularly faecal contamination, suspended sediment and clarity, weed proliferations, nutrients, fish distribution).
Why Do We Want to Use the Oteramika Catchment?
The Oteramika was selected for the trial catchment programme for several reasons. The regional council had already gathered a considerable amount of information on resources within the catchment, through consent monitoring and the dairy farming expansion investigation. The catchment has a good mix of intensive sheep and dairy farming, with some cropping. It lies on both flat land and rolling hill country; typical of much of Southland's farming land, and contains a mixture of well drained and poorly drained soils. The water resources in the catchment are highly important to land owners and currently, these water resources are showing signs of stress in terms of providing an adequate supply of clean water for human users and a suitable habitat for a 'pollution intolerant" aquatic community. Finally, a landcare Group Steering Committee has been formed in the catchment and discussions with this group indicate a willingness to see, and participate in, investigations associated with catchment resources in the Oteramika.
What Will We Do with All this Information and Monitoring Data?
By developing a co-ordinated approach with local authorities, land users, and research agencies to determine how land use activities affect soil health and water resources, it is hoped that the trial catchment programme will enable the development of sound and justifiable land and water management policies that can be applied throughout Southland.
Eventually, we would like to model the movement of potential contaminants of water in and out of the catchment and, using the information we gain from characterising the catchment (i.e., farming practices, soil types, soil leaching, rainfall, ground and surface water pathways), be able to predict the effect of various land use practices on water quality within specific parts of the catchment.
Trends identified in this and other surveys will be reported back to the landowners in the catchment, probably by way of the Oteramika Landcare Steering Committee and newsletters, which we hope to introduce as the catchment investigation programmes becomes more established.
Contact for Enquiries
MAF Information Services
Pastoral House
25 The Terrace
PO Box 2526
Wellington, NEW ZEALAND
Fax: +64 4 894 0721
Contact this person
