The use of an ecologic classification to improve water resource planning in New Zealand

摘要

The Resource Management Act (RMA) legislates the management of most natural resources in New Zealand. The RMA invokes ecosystem-based management by requiring that regulation be based on managing the effects of resource according to "the life supporting capacity" of the environment. The management of water resources under the RMA is carried out at the regional level by regional councils. Regional councils can develop regional water plans to establish objectives and criteria for water management. Regional water planning under the RMA has been problematic, and regional plan objectives developed under the RMA have been criticized as too broad and not sufficiently quantified. As a consequence, many resource users are unconvinced of the need for the regulatory criteria promulgated by plans, whereas other groups are concerned that the environment is inadequately protected. This article proposes that a lack of ecologically relevant management units has prevented regional water plans from fulfilling their intended function under the RMA. Then it introduces the use of River Environment Classification as a means of defining units for assessment and management, and provides three case studies that demonstrate its potential to support regional water management planning. The discussion shows that the specificity of regional assessments can be increased if ecologic variation is stratified into distinctive units (i.e., units within which variation in the characteristics of interest is reduced) as part of the assessment process. The increased specificity of the assessments increases the possibility that regional objectives and criteria for water management can be derived that are quantitative and justifiable and that provide certainty for stakeholders. The authors conclude that greater choice and meaning can be generated in regional planning processes if regional variation in ecologic characteristics is stratified using a classification, and if classes are used as units for assessment and management.