RiVAS and RiVAS+: Opportunities for application of a multi-criteria river value assessment system approach which considers existing and potential states

Abstract

The River Values Assessment System (RiVAS) uses a combination of expert panels and multi criteria analysis to identify primary attributes (or main features) of river values (e.g., whitewater kayaking, native birds) and their key indicators. The resulting data set is used to rank rivers for their existing (instream) and potential (out-of-stream) significance. The RiVAS method has been applied to seven values and tested across a range of councils with most focus in Tasman District. The tool has demonstrated utility and is very cost effective to implement. Further development has now led to RiVAS+ to consider potential significance for instream values, using the same attributes and indicators, and also identifying the interventions needed to achieve these potential future states (e.g., water quality improvements, willow removal, increased flows). RiVAS+ enables instream uses to be considered on the same basis as out-of-stream opportunities. RiVAS+ can be undertaken more-or-less concurrently with RiVAS and enables a range of applications. First, it allows decision makers to gain an understanding of the difference between existing relative importance or significance of a value and its potential (if restored or developed). Second, it enables better evaluation of potential restoration or development options in a range of circumstances including where water resource development is planned. Finally, with further input it might be possible to quantify the cost of the interventions which would then allow better consideration of mitigation and other options in resource management policy and decision making processes. In this paper we demonstrate the method and the opportunities.