The role of science in setting water resource use limits: case studies from New Zealand

Abstract

Water resource use limits ensure protection of environmental values and define the availability and reliability of water supply for out-of-channel use. We examined how three types of scientific tools (environmental flow setting methods, hydrological analyses for setting total allocations and spatial frameworks) have been used to define limits across jurisdictional regions comprising multiple catchments in New Zealand. We found that recently developed minimum flow and total allocation setting tools are widely used. Spatial frameworks are increasingly used to discriminate and account for variation in environmental characteristics, thereby increasing the specificity of water resource use limits. The uptake of scientific tools has enabled improvements in the clarity of water management objectives and the transparency of limits defined by regional water management plans. We argue that more integrated use of scientific tools could improve the clarity and transparency of regional limits by explicitly demonstrating the trade-off between out-of-channel use and protection of environmental values.

Dissolved oxygen criteria for freshwater fish in New Zealand: a revised approach

“…Firstly, they are imposed to constrain human-induced alteration of water quality and quantity to levels that are considered sufficient to sustain environmental values. Secondly, they are necessary to ensure that the total availability of water resources and their reliability is quantified and understood (Snelder et al 2013). In order to set effective and transparent limits that meet environmental objectives, managers require biologically relevant guidelines that reflect both lethal and sub-lethal effects, and indicate an appropriate level of protection under the influence of an environmental stressor.…”

Comparing and combining physically-based and empirically-based approaches for estimating the hydrology of ungauged catchments

“…Zealand must comprise at least a minimum flow (the flow below which no water can be 63 abstracted) and an allocation limit (a limit on the amount of abstraction taken from the 64 resource) (New Zealand Government, 2011; Snelder et al, 2013). 65…”

The changing role of ecohydrological science in guiding environmental flows

“…This has prompted the search for thresholds of hydrological alteration that cause significant ecological change, such as minimum flow determination. Such relationships have been developed in many countries, including Australia (Arthington et al 2014), Japan (Sui et al 2014) and New Zealand (Snelder et al 2014). Richter et al (2012) suggested a precautionary standard of 10% alteration in any flow variable from natural flows to afford a high level of ecological protection in the absence of detailed site-specific data.…”

“…Banks and Docker (2014) reported that institutional arrangements for flow releases from dams in the Murray-Darling Basin, Australia, are organized for irrigation and it is difficult to respond to environmental flow needs. Snelder et al (2014) argued that the uptake of scientific tools in New Zealand has enabled improvements in the clarity of water management objectives and the transparency of limits defined by regional water management plans. Even when environmental flows have been implemented, there must be appropriate monitoring and assessment of compliance.…”