Waterways Centre for Freshwater Management: Conference Contributions
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Item Open Access Mine remediation in New Zealand: Lessons from the (recent) past(University of Canterbury. Waterways Centre for Freshwater Management, 2015) Webster, J.G.Two mines closed within 25yrs of each other, but with very different rehabilitation approaches. Lack of rehabilitation has led to serious, long term sediment contamination at Tui… particularly Mn, Cd and Zn Similar contamination of stream sediment would result from Golden Cross (Mn, Zn, As) but for ongoing WTP operation Need to identify these potential geochemical legacy issues before mining, and design an effective rehabilitation plan (or not mine).Item Open Access Collaborative Governance and Accountability(University of Canterbury. Waterways Centre for Freshwater Management, 2014) Jenkins, B.R.Item Open Access A history of the environmental impact of NZ’s only mainland base: Vanda Station(University of Canterbury. Waterways Centre for Freshwater Management, 2015) Webster-Brown, J.G.; Hawes, I.Vanda Station was built beside Lake Vanda in the Wright Valley, Victoria Land in 1968. It was occupied every summer field season, and occasionally over winter. In 1993 it was removed when the rising level of Lake Vanda threatened to flood the site. Vanda Station’s lifetime spanned a period of transition from little concern over environmental impacts in the Dry Valleys, to the beginning of the stringent code of conduct that is in place today. The legacy of environmental consequences can now provide unique insights into the lasting impacts of this mode of human activity on the Antarctic environment, and the ability of time, environmental change and human endeavour to remediate or amplify those effects. The assessment of environmental impacts began just prior to the removal of the station in which specific sites of soil contamination, including an an area of routine greywater disposal in a gully beside the main buildings were identified. A second assessment was undertaken in 1997, on the partially remediated but still unflooded site, which identified discrete areas of residual chemical contamination particularly in “Greywater Gully”. The lake level has continued to rise and now, just over 20 years after its remediation, the station site has almost completely flooded. “Greywater Gully” is now under 3 - 4m of lake water. In December 2014 we resampled and reanalysed these lake waters, flooded sediments and the few remaining exposed contaminated soils, to determine whether or not, the legacy of Vanda Station includes a lasting impact on its environment.Item Open Access Phosphorous from Agricultural Run-off: New insights from Monitoring and Modelling(University of Canterbury. Waterways Centre for Freshwater Management, 2014) Webster-Brown, J.G.; Waters, A.S.The management of phosphorous (P) in agricultural run-off currently focuses on trapping P-bearing sediment in riparian zones or settlement ponds. This is based on the common assumption that P is almost entirely bound to suspended particulate material (SPM) in the run-off and immediate receiving waters. In this study, this assumption has been held up to scrutiny, using existing monitoring data for dissolved reactive P (DRP) and total P in the Te Waihora/Lake Ellesmere and Wairewa/Lake Forsyth catchments, and a geochemical modelling approach. Long term monitoring data for the lakes1 confirms that P has indeed been predominantly bound to SPM in the water column (DRP averaged <10% of total P) over the monitoring period. However, in the tributaries there has been considerably more variability in the fractionation of P, and a higher proportion of DRP. In the Selwyn River, for example, DRP has made up (on average) 50% of the total P concentrations (38 yrs of monthly monitoring data1). In the LII River, DRP has made up 67% of the total P concentrations (19 years of monthly monitoring data1). In the smaller tributaries of Te Waihora, DRP has ranged from 34% (an average for creeks and streams) to 50% (an average for farm drains) of total P, over the 18 years that monitoring data has been collected by students of Lincoln and Canterbury universities2,3. Similar results have been observed in a recent 10 month survey of the tributaries of Wairewa, in which DRP averaged 30-60% of total P. During flood events the P fractionation has changed to favour a greater percentage of SPM-bound P in all tributaries monitored. Using water chemistry and SPM compositions typical of these lake and tributary environments, the geochemical model PHREEQC has been used to determine principal controls on P binding to SPM. A sensitivity analysis approach was used to establish the role of variables such as the iron oxide content of the SPM, redox conditions, pH and the concentrations of competing ions such as SO4. The potential precipitation of P-phases such as Ca-, Fe- and Mn-phosphates was also considered. While the uptake of P by phytoplankton could not be represented in the geochemical model, the correlation between in total P and chlorophyll-a observed in the long term monitoring data from both lakes1 could be used, together with a mass balance approach, to predict the effect of phytoplankton growth on P fractionation. It is proposed that this modelling approach can be used to predict the optimal conditions for P-binding to SPM, and therefore help identify the best options for retention and immobilisation of P, before it reaches important water features in a catchment.Item Open Access Canterbury Water Management Strategy(University of Canterbury. Waterways Centre for Freshwater Management, 2014) Jenkins, B.; Friend, J.; Midgley, G.Item Open Access The Development of Sustainable Alternatives to Applicants' Proposals Using Collaborative Approaches(University of Canterbury. Waterways Centre for Freshwater Management, 2013) Jenkins, B.R.The purpose of the Resource Management Act is to achieve sustainable management. However the development of alternatives is primarily the responsibility of applicants. In practice this usually leads to proposals that maximise the interests of applicants and result in adverse effects at the margins of acceptability. This paper describes the application of collaborative approaches to two controversial storage proposals in Canterbury – a dam on the Orari River and the Hurunui Water Project (a storage on the South Branch of the Hurunui River and control gates on Lake Sumner). Both processes led to the development of different alternatives which were superior in terms of sustainable management, lower impacts and greater community acceptance – respectively an off-river storage taking high flows from the Rangitata River, and, a series of storages on the Waitohi River, a tributary to the Hurunui. The use of collaborative processes as an alternative to RMA processes to resolve issues was initially resisted by applicants. However there has been a high level of acceptance of the value of collaboration after innovative alternatives were developed. Some of the key learning outcomes from this approach include: the value of collaborative engagement with affected communities outside of adversarial RMA processes; the improvements in alternative generation from collaboration if affected communities can meaningfully participate in decisions on alternative selection; and, the limitations of RMA processes in achieving sustainable management.Item Open Access Collaborative Management: Community Engagement Process as the Decision Making Process(University of Canterbury. Waterways Centre for Freshwater Management, 2013) Jenkins, B.; Henley, G.Planning theory identifies a step-wise process for making decisions which typically include the following steps: define the problem, develop alternatives, evaluate alternatives, and make the decision. We are seeing the growth of multi-criteria decision making frameworks that can score different factors and weight different criteria to provide overall scores for alternatives to indicate a preferred decision. Legal processes have been developed with complex submission and submission-on-submissions procedures to inform independent commissioners of the variety of viewpoints that need to be considered in their deliberations on the merits of proposals. However these technical and legal processes may not be the most effective decision making processes for the sustainable management of scarce resources involving multiple users. Ostrom has identified “collective choice arrangements” as one of the design principles for the management of common pool resources, such as water or fisheries. This paper describes the decision making process for developing the Canterbury Water Management Strategy. This process was designed to be dynamic and collaborative with stakeholder and community engagement. The steps in the community engagement process defined the decision making process. This is not to say that the technical and legal processes were not followed, rather, they were subsidiary to the community engagement process. The paper describes the activities associated with the seven milestones of the community engagement process: (1) Release and announcement (2) Definition of the process (3) Identification of the breadth of uses and benefits (4) Public reporting of uses and benefits (5) Achievement of depth and sophistication of strategies and substrategies (6) Public engagement on strategy options (7) Implementation and update. The community engagement process was successful in achieving widespread acceptance of the proposed strategy which is now being implemented.Item Open Access Progress of the Canterbury Water Management Strategy and some emerging issues(University of Canterbury. Waterways Centre for Freshwater Management, 2013) Jenkins, B.R.This paper reviews the progress to date of the Canterbury Water Management Strategy and identifies key developments and emerging issues. The paper examines the provision of storage, water use efficiency, environmental flow adjustments, nutrients from land use intensification, biodiversity enhancements and kaitiakitanga. The collaborative process has led to some more sustainable changes. One is the use of off-river storage and tributary storage as alternatives to mainstem storage. A second is improved environmental flow regimes by increasing minimum flows and reducing allocations at low flows; but enabling access to allocations at higher flows and providing time to adjust to new requirements. The parallel achievement of reduced nitrate loads and increased irrigation areas is proving problematic. Water use efficiency is advancing on some fronts – piped distribution replacing canal distribution and ongoing conversions to spray irrigation – but not on others – soil moisture demand irrigation and reallocation of surface and groundwater use to enhance recharge. Biodiversity enhancements and incorporating kaitiakitanga in water management are showing positive progress. Some of the key emerging issues include the allocation of nitrate capacity between existing and new users, and, the need for increased capacity for predictive modelling and field measurement to improve management of the use of scarce water and the cumulative effects of its use.Item Open Access Managing Water Quantity at Allocation Limits(University of Canterbury. Waterways Centre for Freshwater Management, 2013) Jenkins, B.R.