Waterways Centre for Freshwater Management: Reports
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Item Open Access Managing peri-urban floodplains and urban-rural connectivity: A case study in ecosystems governance following a disaster event(2019) Orchard, Shane; Challies, EPeri-urban environments are critical to the connections between urban and rural ecosystems and their respective communities. Lowland floodplains are important examples that are attractive for urbanisation and often associated with the loss of rural lands and resources. In Christchurch, New Zealand, damage from major earthquakes led to the large-scale abandonment of urban residential properties in former floodplain areas creating a rare opportunity to re-imagine the future of these lands. This has posed a unique governance challenge involving the reassessment of land-use options and a renewed focus on disaster risk and climate change adaptation. Urban-rural tensions have emerged through decisions on relocating residential development, alternative proposals for land uses, and an unprecedented opportunity for redress of degraded traditional values for indigenous (Māori) people. Immediately following the earthquakes, existing statutory arrangements applied to many recovery needs and identified institutional responsibilities. Bespoke legislation was also created to address the scale of impacts. Characteristics of the approach have included attention to information acquisition, iterative assessment of land - use options, and a wide variety of opportunities for community participation. Challenges have included a protracted decision-making process with accompanying transaction costs, and a high requirement for coordination. The case typifies the challenges of achieving ecosystem governance where both urban and rural stakeholders have strong desires and an opportunity to exert influence. It presents a unique context for applying the latest thinking on ecosystem management, adaptation, and resilience, and offers transferable learning for the governance of peri-urban floodplains worldwide.Item Open Access How can we prevent the extinction of whitebait?(2017) Orchard, ShaneA recent NZ Geographic article has stirred up an already vigorous debate (see the full article here goo.gl/TcWWU8). “What we call ‘whitebait’ are the juveniles of five fish species: giant kōkopu, banded kōkopu, shortjaw kōkopu, īnanga and kōaro. The first is predicted to go extinct by 2020, the second by 2023, and the rest by 2034”. The key point here is extinction. It refers to the death of the last individual. If the above predictions were correct this would occur in 3, 6 and 17 years for these species. Such extinction might occur through one of these 3 events: 1) all adult fish die before spawning 2) spawning occurs but the eggs die 3) eggs hatch but larvae and juvenile (whitebait) mortality causes extinction (or contributes to #1) The presence of whitebait shows that adult fish have successfully bred. Whitebait numbers have declined since historical times yet the current trend is impossible to gauge and likely fluctuates between years. The life cycle depends of producing lots of juvenile whitebait, most of which will die. Those making it to adulthood are the breeders for the next generation.Item Open Access Survey method for locating īnanga spawning sites at a catchment scale(2017) Orchard, Shane; Hickford, MikeĪnanga (Galaxias maculatus) is one of five galaxiid species that provide New Zealand’s ‘whitebait’ fishery. Four of the five species are also threatened to various degrees. The management of whitebait species is therefore important for conservation objectives as well as for maintaining the fishery. Aside from regulations on fishing activities (which target the juvenile fish on their migration from the ocean into freshwater systems) the degradation of habitat is a particular focus. Although all life stages are important, the protection of spawning habitat may be particularly important for īnanga. It is found in very specific places on the riparian margins of coastal waterways. These areas have become degraded by historical activities associated with urbanisation and other intensive land uses near waterways. These changes have the potential to dramatically impact on fish populations since the inanga life cycle is relatively short (1 -2 years). Poor spawning success in one season can be expected to reduce the stock of whitebait and adult populations in the next season. Repeat cycles of this may very quickly diminish fish stocks - especially if it occurs at many spawning sites simultaneously. In reality, some rivers have become ‘sinks’ that contribute little to maintaining stocks each year1. The fish population is reliant on other rivers (the ‘sources’) where spawning success is higher.Item Open Access Using citizen science for coastal data collection(New Zealand Coastal Society, 2016) Orchard, ShaneCitizen science has come of age in New Zealand and there are a wide range of opportunities for coastal scientists and practitioners to make use of, or contribute to it. This article provides an overview of some recent highlights and progress with a focus on projects supported by NatureWatch NZ, a national platform for citizen science in New ZealandItem Open Access Potential roles for coastal protected areas in disaster risk reduction and climate change adaptation: a case study of dune management in Christchurch, New Zealand(IUCN, Gland, Switzerland, 2014) Orchard, Shane; Murti, R; Buyck, CDunes provide a range of benefits for coastal hazard management. This includes protection from erosion, inundation, and storm surge events, and may include disaster risk reduction benefits in large magnitude events. However, New Zealand’s coastal dune ecosystems have become heavily modified in recent decades and the space available for dunes has become severely restricted in many areas. The restoration and protective management of indigenous dune ecosystems is now an urgent conservation issue. Since plant communities influence dune form and dynamics, the protection of dune biodiversity is important to their coastal hazard management role. The management of dunes as Protected Areas is now a common approach and can be especially important in locations where development and land use patterns have encroached on the space available for dunes, or where intensive management responses to other threats are required. There are now many examples of dune restoration projects at sites where former dunes had largely disappeared, or where the dune plant community has been impacted by invasive species. These projects provide opportunities to assess the potential for protected area management to deliver benefits for coastal hazard management within an integrated approach to coastal management. Additionally, forward planning for the adaptive management of coastlines is needed in the context of predicted sea level rise, and includes consideration of the values of protected areas and the future roles they may play. This case study presents results from an example of restorative dune management within the Christchurch Coastal Park network with a focus on the potential roles of these parks in disaster risk reduction and adaptation to climate change.Item Open Access Development of a fine-scale salinity model for the Avon Heathcote Estuary Ihutai(2016) Orchard, Shane; Measures, RichardThe focus of this study is on understanding salinity changes in the vicinity of the freshwater-saltwater interface in estuarine ecosystems. In these areas, species, habitats and ecosystems that are adapted to brackish conditions are expected to migrate in response to salinity changes under sea level rise. For the Avon Heathcote Estuary in Christchurch, an existing fine scale hydrodynamic model was available but not calibrated for salinity. A collaborative project was designed between the University of Canterbury and NIWA to calibrate the model and develop a scenario modelling approach for sea level rise at a level of resolution sufficient for understanding potential effects on important habitats. The purpose of this report is to provide a description of the model development process and an illustration of model outputs from an initial set of modelled scenarios for sea level rise.Item Open Access Spatial effects of the Canterbury earthquakes on inanga spawning habitat and implications for waterways management(2016) Orchard, Shane; Hickford, MikeThe Canterbury earthquakes resulted in numerous changes to the waterways of Ōtautahi Christchurch. These included bank destabilisation, liquefaction effects, changes in bed levels, and associated effects on flow regimes and inundation levels. This study set out to determine if these effects had altered the location and pattern of sites utilised by īnanga (Galaxias maculatus) for spawning, which are typically restricted to very specific locations in upper estuarine areas. Extensive surveys were carried out in the Heathcote/Ōpāwaho and Avon/Ōtākaro catchments over the four peak months of the 2015 spawning season. New spawning sites were found in both rivers and analysis against pre-earthquake records identified that other significant changes have occurred. Major changes include the finding of many new spawning sites in the Heathcote/Ōpāwaho catchment. Sites now occur up to 1.5km further downstream than the previously reported limit and include the first records of spawning below the Woolston Cut. Spawning sites in the Avon/Ōtākaro catchment also occur in new locations. In the mainstem, sites now occur both upstream and downstream of all previously reported locations. A concentrated area of spawning was identified in Lake Kate Sheppard at a distinctly different location versus pre-quake records, and no spawning was found on the western shores. Spawning was also recorded for the first time in Anzac Creek, a nearby waterway connected to Lake Kate Sheppard via a series of culverts.Item Open Access Identifying inanga spawning sites in plans: options for addressing post-quake spawning in Ōtautahi Christchurch(2016) Orchard, ShaneThe purpose of this assessment is to compare records of known inanga spawning sites in the waterways of Ōtautahi Christchurch from before and after the Canterbury earthquakes, with particular emphasis on information used in the design of planning methods for spawning site protection.Item Open Access Cobden wetlands īnanga habitat assessment and recommendations for future management(2017) Hickford, Mike; Orchard, ShaneThis short report describes an assessment of the Cobden Island floodplain area and Aromahana Lagoon shoreline. A large scale ecological restoration project has been underway since 2013 on Cobden Island. The project has made considerable progress towards its objectives. The level of weed control being maintained has been very successful and the lack of gorse, broom, and blackberry is notable considering the size of site and high light levels. In most places a dense grass sward has developed grading into rushes and herbs in many wetter areas creating a mosaic of riparian vegetation types. Within the artificial channel network, a variety of in-stream habitats were also noted as a result of different channel widths, incision depths, shading, exposure to flood tide flows, and sedimentation rates. With regards to īnanga spawning habitat, the project has hugely increased the length of river/channel bank available for spawning by 7 km, with few comparable sites in New Zealand.Item Open Access Coastal & Marine Citizen Science in New Zealand NZMSS Workshop Proceedings(2016) Kettles, Helen; Orchard, ShaneA group of 29 participants met for the Coastal & Marine Citizen Science Workshop, on 7 July 2016, straight after the joint New Zealand Marine Sciences Society (NZMSS) and Australian Marine Sciences Association (AMSA) conference in Wellington. This was a first meeting specific to coastal and marine citizen science in New Zealand. A wide range of experience and skills were represented and included people involved in current citizen science projects and scientists with interests in the potential of citizen science to address wider information needs. The energy and enthusiasm of the participants also reflected the high interest in this topic. There were two major workshop topics: preparation of a citizen science projects list for a national estuaries science and management summary, and an exercise to explore gaps and opportunities for citizen science to assist coastal science and management objectives in. Examples from both New Zealand and Australian helped to enrich the conversation and identify priorities for advancing these topics in the short to medium term. Outcomes of the workshop included: a list of citizen science projects currently underway in coastal and marine environments to add to the national picture of citizen science, identification of opportunities for progressing this area of work in New Zealand, a list of priority actions to undertake in the short-term. Another important outcome was the opportunity for the network of practitioners to make connections and share ideas.Item Open Access Integrated assessment frameworks for evaluating large scale river corridor restoration(Avon Ōtākaro Network, 2017) Orchard, ShaneThis report is the third and final report in the Ecological Regeneration Options (ERO) project series. Its purpose is to assist in developing integrated assessment methodologies for evaluating ecological regeneration options in the Avon-Ōtākaro Red Zone (AORZ). This is an important topic to ensure that their potential benefits are recognised alongside those of alternative land uses. This report complements the previous two reports in the ERO series. These provide information on floodplain restoration principles (Orchard, 2017) and an assessment of restoration opportunities in the AORZ using a local knowledge approach (Orchard et al., 2017). The focus of this report is on facilitating robust assessments of the ecological regeneration options presented by the AORZ. A specific objective was to develop an integrated assessment framework to support comparison of those options against each other and against alternative land uses. First, the topics of river corridor evaluation and integrated assessment are briefly introduced and examples of integrated assessment in relevant planning contexts identified. A framework for the integrated assessment of ecological regeneration options is then presented.Item Open Access Floodplain restoration principles for the Avon Ōtākaro Red Zone. Case studies and recommendations.(Avon Ōtākaro Network, 2017) Orchard, ShaneThe Canterbury region of New Zealand experienced a sequence of strong earthquakes during 2010-2011. Responses included government acquisition of many thousands of residential properties in the city of Christchurch in areas with severe earthquake effects. A large and contiguous tract of this ‘red zoned’ land lies in close proximity to the Ōtākaro / Avon River and is known as the Avon-Ōtākaro Red Zone (AORZ). The focus of this study was to provide an overview of the floodplain characteristics of the AORZ and review of international experience in ecological restoration of similar river margin and floodplain ecosystems to extract restoration principles and associated learnings. Compared to pre-earthquake ground levels, the dominant trend in the AORZ is subsidence, together with lateral movement especially in the vicinity of waterway. An important consequence of land subsidence in the lower Ōtākaro / Avon River is greater exposure to flooding and the effects of sea level rise. Scenario modelling for sea level rise indicates that much of the AORZ is exposed to inundation within a 100 year planning horizon based on a 1 m sea level rise. As with decisions on built infrastructure, investments in nature-based ‘green infrastructure’ also require a sound business case including attention to risks posed by climate change. Future-proofing of the expected benefits of ecological restoration must therefore be secured by design. Understanding and managing the hydrology and floodplain dynamics are vital to the future of the AORZ. However, these characteristics are shared by other floodplain and river restoration projects worldwide. Identifying successful approaches provides a useful a source of useful information for floodplain planning in the AORZ. This report presents results from a comparative case study of three international examples to identify relevant principles for large-scale floodplain management at coastal lowland sites.Item Open Access Restoration opportunities assessment for the Avon Ōtākaro Red Zone using a local knowledge approach(Avon Ōtākaro Network, 2017) Orchard, Shane; Meurk, C; Smith, EFollowing the Canterbury earthquake sequence of 2010-11, a large and contiguous tract of vacated ‘red zoned’ land lies alongside the lower Ōtākaro / Avon River and is known as the Avon-Ōtākaro Red Zone (AORZ). This is the second report in the Ecological Regeneration Options (ERO) project that addresses future land uses in the AORZ. The purpose of this report is to present results from an assessment of restoration opportunities conducted in April 2017. The objectives of the assessment were to identify potential benefits of ecological restoration activities across both land and water systems in the AORZ and characterise the key options for their implementation. The focus of this report is not to provide specific advice on the methods for achieving specific restoration endpoints per se. This will vary at different sites and scales with a large number of combinations possible. Rather, the emphasis is on providing an overview of the many restoration and regeneration options in their totality across the AORZ. An additional objective is to support their adequate assessment in the identification of optimum land uses and adaptive management practices for the AORZ. Participatory processes may play a useful role in assessment and stakeholder engagement by providing opportunities for social learning and the co-creation of new knowledge. We used a facilitated local knowledge based approach that generated a large quantity of reliable and site specific data in a short period of time. By inviting participation from a wide knowledge-holder network inclusivity is improved in comparison to small-group expert panel approaches. Similar approaches could be applied to other information gathering and assessment needs in the regeneration planning process. Findings from this study represent the most comprehensive set of concepts available to date to address the potential benefits of ecological regeneration in the AORZ. This is a core topic for planning to avoid missed opportunities and opportunity costs. The results identify a wide range of activities that may be applied to generate benefits for Christchurch and beyond, all involving aspects of a potential new ecology in the AORZ. These may be combined at a range of scales to create scenarios, quantify benefits, and explore the potential for synergies between different land use options. A particular challenge is acquiring the information needed within relatively short time frames. Early attention to gathering baseline data, addressing technical knowledge gaps, and developing conceptual frameworks to account for the many spatio-temporal aspects are all key activities that will assist in delivering the best outcomes. Methodologies by which these many facets can be pulled together in quantitative and comparative assessments are the focus of the final report in the ERO series.