- Programme Title:The potential use of tradeable emission permits as economic instruments in addressing water quality problems caused by agriculture (non-point source pollution).
- Programme Title:Development of decision-support tools for managing water quality in agricultural landscapes
- Programme Title: Guidelines for constructed wetland treatment of dairy shed oxidation pond discharges
8.3 Water Quality
Abating non-point discharge from agriculture is becoming the goal of many regional and central authorities in New Zealand. Because of the very nature of this type of discharge, authorities have been unable to address the problem, as targeting the polluter is almost impossible. Models were developed to assist authorities. Methods for reducing discharge from identifiable sources such as dairysheds were also developed.
8.3.1
Summary
Objective 1:Development of collective non-point discharge models
Objective 2: Development of economic instrument model
Description - Objective 1: Development of collective non-point discharge models
To develop a collective (catchment) responsibility model for water quality and develop the basis for the introduction of tradeable discharge permits, incorporating processes of attitudinal changes in the model to ensure the long-term acceptance and implementation of such a model will be successful. To develop collective resource management goals based on:
- the definition of non-point discharge;
- net water quality from the catchment area which would meet the standards set by different groups;
- the financial performance of farmers derived from changing land and water management practices; economic efficiency of the model’s implementation and long term operation; and
- specialised monitoring requirements.
Description - Objective 2: Development of economic instrument model
To develop a model of tradeable emission permits which tie the individual farmer responsibility to the collective goal. The permit system will ensure standards which not only meet the biophysical sustainable requirements for the environment, but also the social and economic conditions, and ensure the standards of the Resource Management Act 1991 are met. Also;
- exploring the financial and environmental feasibility, community acceptability, implementation, tradeability and long-term viability of the permit system; and
- developing all the regional and institutional frameworks for the integrations of the model and seek to justify any recommendations and findings made.
Approach & Outcomes
A report has not yet been received.
8.3.2
Programme Title: Development of decision-support tools for managing water quality in agricultural landscapesResearch Leader: Dr H Rodda Institution:NIWA |
Summary
A decision support system was set up which links national databases with a physically based, catchment-scale water quality model and a model of agricultural production. The system is linked using a geographical information system (GIS) interface. Equations from the agricultural production model were incorporated into the water quality model. Simulations can be undertaken using climatic data, downloaded directly from one of the databases; and soil, land use and topographic information obtained from GIS coverages of a selected catchment. Model output, in terms of water quality and agricultural production criteria, is displayed in the form of colour-coded maps. These maps will aid policy makers in making decisions that will affect land management practices in agricultural catchments.
Description
To interface the BNZ model with the GIS-database module for:
- identifying major combinations of agriculture, soil type & slope for particular biogeographic regions; and
- using this information to simulate ‘model’ catchment outputs applicable to the climatic conditions of that region.
Approach & Outcome
A catchment model specifically developed for NZ conditions (Basin-New Zealand, BNZ) has been successfully used by NIWA and AgResearch to predict changes in stream water quality resulting from different farming practices. Simultaneously NIWA was developing geographical information system (GIS) tools to interface with large database (land resources, climate, hydrological). In this way, the effects of agriculture on stream water quality throughout New Zealand could be examined. The incorporation of an economic model, Outlook, into the system would enable the effect on production to be assessed in addition to the environmental impact of different agricultural management policies.
The decision support system was set up linking national databases with a physically based, catchment-scale water quality model and a model of agricultural production. The system is linked using a GIS interface. Equations from the agricultural production model were incorporated into the water quality model. Simulations can be undertaken using climatic data, downloaded directly from one of the databases; and soil, land use and topographic information obtained from GIS coverages of a selected catchment. Model output, in terms of water quality and agricultural production criteria, is displayed in the form of colour-coded maps. These maps will aid policy makers in making decisions that will affect land management practices in agricultural catchments.
It was decided not to use data from the Land Resource Inventory as originally intended for specific catchment studies, as more up-to-date, accurate and detailed data are needed. Testing of the system against measured data from catchments is being carried out in the 1996/97 programme.
8.3.3
Programme Title: Guidelines for constructed wetland treatment of dairy shed oxidation pond dischargesResearch Leader: Mr C Tanner Institution:NIWA |
Description
To develop practical guidelines for the use of constructed wetland treatment systems to upgrade dairy shed oxidation pond discharges by;
- developing standard guidelines for the design, construction, planting and operation of constructed wetlands providing three different levels of dairy shed waste water treatment, with emphasis on biochemical oxygen demand (BOD), suspended solids, ammonia nitrogen and faecal bacteria removal; and
- providing information required for the evaluation and appropriate use of wetland treatment including: site requirements and constraints, estimated construction costs, predicted levels of treatment, and ancillary benefits of wetlands for wildlife and landscape enhancement.
Approach & Outcome
Treatment and associated design parameters were developed and landscaping concepts and drawings prepared. The results of farm-scale wetland treatment studies and the scope and key content of the guidelines were previewed at a recent symposium held at Massey University, to gain feedback from within the dairy industry and from regulatory agencies, farm consultants and other researchers.
The information will be finally released in March 1997.
Conferences
Tanner, C.C. and Sukias, J.P.S. (1996): Wetland treatment of dairy shed wastewater. Proceedings of the "Tertiary Options for Dairy Shed and Piggery Wastewaters", Department of Agricultural Engineering, Massey University, June 2.
Contact for Enquiries
Farm Monitoring Programme Manager
Monitoring and Evaluation
MAF Policy
PO Box 2526
Wellington
NEW ZEALAND
Phone: +64 4 894 0623
Fax: +64 4 894 0741
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