Integrated Catchment Management Research Articles

Sediment Management Strategies for Hydropower Reservoirs in Active Agricultural Area

Ringlet, Jor and Mahang reservoirs are part of Cameron Highlands – Batang Padang Hydroelectric Scheme. Conversion of forest to agricultural and urban area within the catchment has caused Ringlet Reservoir to suffer severe sedimentation problem and waste dumping. This has caused operational difficulties to the hydropower operator. Based on estimation, sediment inflow into Ringlet Reservoir has increased multiple folds from 25,000 m3/year in 1960s up to between 120,000 m3/year to 200,000 m3/year in 2010. This reduces the total storage capacity of Ringlet Reservoir to almost 50% of its original design value, and subsequently affects Jor and Mahang Reservoirs. Bertam Intake is often choked by the sediment built up within the area, thus limiting the running hours of the plant to generate electricity. Without sediment management strategies, the incoming sediment load into Ringlet Reservoir would increase tremendously and can cause the hydropower scheme to cease operation faster that its design life expectancy. Various mitigation strategies have been implemented such as dredging, construction of check dams and settling basins and flushing from the bottom outlet, resulting to an increase in storage. Despite these efforts which focus within the reservoir, the best solution is by control the sediment and waste at source, through the concept of an integrated catchment management. This requires concerted effort from the local authorities and public to ensure successful implementation. This paper outlines the methods, analyses and results of various mitigation strategies.

Integrated catchment management for reducing pesticide levels in water: Engaging with stakeholders in East Anglia to tackle metaldehyde

In the agriculture intensive eastern region of England, plant protection products are widely applied to protect crops such as wheat and oilseed rape from pests and diseases, thus creating a risk of reaching nearby water courses through surface runoff. The EU Drinking Water Directive sets a stringent limit of 0.1 μg/l and 0.5 μg/l for individual and total pesticides respectively in treated potable water. However, peak metaldehyde levels have been persistently detected in raw water and reducing them to these limits has proven challenging and costly, in particular when using conventional treatment. In line with the EU Water Framework Directive, a more suitable approach and one adopted by the local water company, Anglian Water Services Ltd., would require moving towards mitigating pollution at source, preferably through participative action with multiple stakeholders in the agricultural industry. Initial findings demonstrate the potential of product substitution for reducing metaldehyde levels in surface waters. Reviewing Anglian Water's “Slug it Out” trial, we discuss key learnings derived from their experiences and make recommendations about the potential of the catchment approach to address the wider pesticide challenge.

Changes in connectivity and hydrological efficiency following wildland fires in Sierra Madre Oriental, Mexico

Fire modifies soil surface, and hence soil hydrological properties change after wildland fires. High fire severity causes partial or total removal of vegetation, reduction of soil aggregate stability and increased water repellency, which are associated with high runoff and erosion. The spatial connection among these runoff sources is an important factor to consider when evaluating fire-induced changes on hillslope and catchment hydrology, as fire generates connected areas of bare soil, which may increase hydrological connectivity and hence post-fire runoff and erosion. The aim of this study was to quantify changes in hydrological connectivity and efficiency in two burned areas in central Mexico. By integrating rainfall simulation and spatial analysis, an index of connectivity (IC) and the lateral hydrological efficiency index (LHEI) were computed based on land/cover use, fire severity and topography within 287 burned sub-basins. Post-fire IC and LHEI were compared with the pre-fire scenario, and the relationship between LHEI and the proportion of burned area was assessed at the sub-basin level. Thresholds of the burned area per fire severity needed to increase LHEI were determined by a classification tree. The index of connectivity and LHEI were higher after wildland fires. The burned area was positively related with LHEI, and at least 43.3% of area burned with high severity is sufficient to produce the highest LHEI. The results are evidence of the effect of fire on hydrological connectivity and efficiency which adds to the understanding of fire–hydrology relations and can be used for integrated catchment management, ecological restoration and risk assessment.

Rivervis: A tool for visualising river ecosystems

There is a growing need to better understand and communicate multi-dimensional river ecosystem processes and properties at the catchment scale for both scientific research and integrated catchment management. Data visualisation is believed as a very useful approach to support this need. However, there is a lack of visualisation applications tailored for river ecosystems, especially for visualising both river environmental data and their spatial and topological relations. To fill up the gap, this paper introduces an R package rivervis, which has been developed as a free, easy-to-use and efficient visualisation solution for river ecosystems. This novel tool is able to visualise riverine data in a compact and comparable way, with retaining the river network topology and reflecting real distance between sites of interest. The rivervis package visualises variables according to their measurement types – either quantitative or qualitative/semi-quantitative data. This type-based principle makes the package applicable for a wide range of scenarios with data in forms of index values, condition gradings and categories. By producing topological river network diagrams, the package helps to understand the functioning and interconnections of riverine ecosystem at the catchment scale, especially the longitudinal upstream-downstream and tributary-mainstream connectivity and relationships. It can also be used to study the associations between biological communities, physical conditions and anthropogenic activities. The Ballinderry River Basin in the UK, as a data-rich river basin with a reasonable complex river network, is used to demonstrate the rationale, functions and capabilities of the R-package.

Evaluating the success of public participation in integrated catchment management

Recognition of the need to manage the water environment in more holistic ways has resulted in the global growth of Integrated Catchment Management (ICM). ICM is characterised by horizontal integration, encouraging interdisciplinary working between traditionally disparate management sectors, alongside vertical integration, characterised by the engagement of communities; central is the promotion of participatory governance and management decision-making. ICM has been translated into policy through, for example, the EU Water Framework Directive and at a national level by policies such as the Catchment Based Approach in England. Research exploring the implementation of these policies has reported success at a catchment level, but further research is required to explore practices of management at local level within catchments. This paper presents the findings of participatory research undertaken with a catchment partnership in the northeast of England to explore the integration of top-down policy translation with how local communities interact with management agencies at sub-catchment scale (a bottom-up perspective). The research found that supra-catchment scale drivers dominate the vertical interplay between management systems at more local levels. These drivers embed traditional practices of management, which establishes public participation as a barrier to delivery of top-down management objectives, resulting in practices that exclude communities and participatory movements at the local level. Although collaboration between agencies at the partnership scale offers a potential solution to overcoming these obstacles, the paper recommends changes to supra-catchment governance structures to encourage flexibility in developing local participatory movements as assets. Further research is necessary to develop new practices of management to integrate local people more effectively into the management process.

Is planting trees the solution to reducing flood risks?

Flood risk and associated impacts are major societal and policy concerns following widespread flooding in December 2015, which cost the UK economy an estimated £5 billion. Increasing advocacy for alternatives to conventional hard engineering solutions is accompanied by demands for evidence. This study provides a systematic review and meta‐analysis of direct evidence for the effect of tree cover on channel discharge. The results highlighted a deficiency in direct evidence. From 7 eligible studies of 156 papers reviewed, the results show that increasing tree cover has a small statistically significant effect on reducing channel discharge. Meta‐analysis reveals that tree cover reduces channel discharge (standardised mean difference −0.35, 95%CI, −0.71 to 0.00), but the effect was variable (I2 = 81.91%), the potential for confounding was high, and publication bias is strongly suspected (Egger Test z = 3.0568, p = .002). Due to the lack of direct evidence the overall strength of evidence is low, indicating high uncertainty. Further primary research is required to understand reasons for heterogeneity and reduce uncertainty. A Bayesian network parameterised with data from the meta‐analysis supports investment in integrated catchment management, particularly on infrastructure density and water storage (reservoirs), for effective responses to flood risk.

Integrated Catchment Management — a UK perspective

Integrated Catchment Management — a UK perspective

Understanding trade-offs in upscaling and integrating climate-smart agriculture and sustainable river basin management in Malawi

This paper presents an assessment of the potential trade-offs between social, economic and environmental objectives when upscaling and integrating climate-smart agriculture (CSA) with integrated catchment management (ICM) at landscape level, with a case study in Malawi. In a workshop, government and NGO representatives and experts assessed trade-offs between the goals of ICM and CSA under four different scenarios of climatic and economic changes. The paper presents a novel combination of scenarios and a trade-off matrix exercise to critically evaluate trade-offs between CSA and ICM and link these to policy challenges and interventions. Our analysis shows that the compatibility of CSA and ICM policies depends on future climatic and economic developments, with a higher prevalence of perceived trade-offs in futures with low economic growth and high climate change. CSA was expected to have limited effect on reducing inequalities and investment in literacy and skills development are critical to ensure that marginalised groups benefit from CSA.

Challenges in implementing integrated catchment management and sustainable stormwater solutions in Bangkok, Thailand

Abstract By reviewing related studies, published journal articles, research and government reports, this study explored the challenges in water governance, focused on the planning for integrated catchment management (ICM) and stormwater source control (SC) in Bangkok and its catchment. The review revealed implementation barriers, and eight categories of challenge: fragmented roles and responsibilities; technocratic bureaucracy; limitations of the regulatory framework; financial barriers; physical barriers; challenges of integrated knowledge; an uncoordinated institutional framework; and limited community and stakeholder involvement. The understanding of barriers to ICM planning and SC approaches is crucial for developing strategies that diminish barriers and increase the implementation of alternative solutions.

Modelling Seismic effects on a Sewer Network using Infoworks ICM

Objectives: The effects of earthquakes on a sewer network can be assessed using different well established methods such as flow monitoring, visual inspection, condition assessments and engineering survey. The main objective of this study is to investigate how hydraulic models were developed and used to assess the immediate devastating impacts of seismic activities on Christchurch’s sewer network. Methods: Infoworks ICM (Integrated Catchment Management) and InfoNet hydraulic modeling tools were used for this investigation. Two hydraulic models (2010 pre-quake model and 2011 postquake model) were developed for Christchurch’s sewer network as part of this assessment. Findings: Hydraulic modelling was found to be a very powerful tool engineers can use to assess the impact of an earthquake and quantify the performance of sewer network. In Christchurch earthquakes caused significant damage to the waste water network. In post-earthquake Christchurch, there was an increase of 33% in the flows to the treatment plant due to earthquake related damage in the network. Application/Innovation: This paper summarizes hydraulic-model building and calibration works for preearthquake and post-earthquake Christchurch to evaluate the impacts of seismic activities on the sewer network. This paper suggests that any modern water authority could implement appropriate hydraulic modelling tools to prepare for any unforeseen situation. Keywords: Earthquake, Infoworks ICM, Modelling, Seismic Effects, Sewer Network

Calculation of intercepted runoff depth based on stormwater quality and environmental capacity of receiving waters for initial stormwater pollution management.

While point source pollutions have gradually been controlled in recent years, the non-point source pollution problem has become increasingly prominent. The receiving waters are frequently polluted by the initial stormwater from the separate stormwater system and the wastewater from sewage pipes through stormwater pipes. Consequently, calculating the intercepted runoff depth has become a problem that must be resolved immediately for initial stormwater pollution management. The accurate calculation of intercepted runoff depth provides a solid foundation for selecting the appropriate size of intercepting facilities in drainage and interception projects. This study establishes a separate stormwater system for the Yishan Building watershed of Fuzhou City using the InfoWorks Integrated Catchment Management (InfoWorks ICM), which can predict the stormwater flow velocity and the flow of discharge outlet after each rainfall. The intercepted runoff depth is calculated from the stormwater quality and environmental capacity of the receiving waters. The average intercepted runoff depth from six rainfall events is calculated as 4.1mm based on stormwater quality. The average intercepted runoff depth from six rainfall events is calculated as 4.4mm based on the environmental capacity of the receiving waters. The intercepted runoff depth differs when calculated from various aspects. The selection of the intercepted runoff depth depends on the goal of water quality control, the self-purification capacity of the water bodies, and other factors of the region.

Managing Multiple Catchment Demands for Sustainable Water Use and Ecosystem Service Provision

Ensuring water, food and energy security for a growing world population represents a 21st century catchment management challenge. Failure to recognise the complexity of interactions across ecosystem service provision can risk the loss of other key environmental and socioeconomic benefits from the natural capital of catchment systems. In particular, the ability of soil and water to meet human needs is undermined by uncertainties around climate change effects, ecosystem service interactions and conflicting stakeholder interests across catchments. This critical review draws from an extensive literature to discuss the benefits and challenges of utilising an ecosystem service approach for integrated catchment management (ICM). State-of-the-art research on ecosystem service assessment, mapping and participatory approaches is evaluated and a roadmap of the key short- and longer-term research needs for maximising landscape-scale ecosystem service provision from catchments is proposed.

Phosphorus transfer at a small catchment in southeastern Brazil: distributed modelling in different land use scenarios

ABSTRACT Identifying and ranking nutrient loss risk areas are important steps towards integrated catchment management. This study aimed to apply the P index model at the Posses catchment, south of the state of Minas Gerais, Brazil. We applied the P index for the current land use at the Posses catchment and for two hypothetical scenarios: scenario 1, in which P fertilizer was applied to all land uses, except for native forests; and scenario 2, which considered the use of P fertilizer as in scenario 1, and that the Environmental Protection Areas referring to the riparian forests and springs were totally restored. Considering current land use, almost the whole catchment area (91.4%) displayed a low P loss risk. The highest P index was associated to croplands and eucalyptus plantations. Regarding scenario 1, areas under pasture fell into the low (15.1%), medium (45.5%), high (27.1%) and very high (12.3%) P index categories. Environmental Protection Areas on scenario 2 decreased the P loss risk from the scenario 1 in 37.6%. Hence, the model outputs indicate that the reforestation of buffer zones can decrease P loss risk in the case increasing use of P fertilizer. The P index model is a potential support tool to promote judicious use of fertilizers and conservation practices at the Posses catchment.

Water governance in New Zealand – challenges and future directions

New Zealand has one of the most devolved water governance regimes in the world. It has been also one of the first countries to give legal recognition to indigenous (Māori) rights for water, and in 2017 the first to give a river legal status as a person. Yet water governance in New Zealand has recently become politically contentious, primarily because of recent declines in water quality of lowland rivers and lakes brought about by land use intensification, especially intensification of dairy farming. This paper reviews water governance arrangements in New Zealand. The legal anchors for water governance are the Resource Management Act 1991 and the Local Government Act 2002. Fresh water is managed by 16 regional councils under a highly devolved statutory planning regime and a system of resource consents for management of land use, water takes and discharges. Regional council boundaries largely follow catchment boundaries which has facilitated integrated catchment management. Central government has in recent years increased the level of national direction for water management. Its National Policy Statement for Freshwater Management 2014 requires regional councils to set requires regional councils to set objectives for all freshwater bodies, with limits on abstractions and discharges, by December 2025. They are also required to implement methods to address over‐allocation and to ensure that, overall, water quality within a region is maintained or improved. Consensus‐seeking collaborative processes are being implemented in many regions to establish these objectives and limits in legally binding regional plans. In 2017, further proposals also seek to improve water quality to make 90% of New Zealand rivers swimmable by 2040. Māori seek that their indigenous interests in water be better recognized in law, and there are public demands that royalty payments be levied on exports of bottled water. Water governance has become a political issue in a country which is actually well endowed with fresh water resources.

Natural flood management, land use and climate change trade-offs: the case of Tarland catchment, Scotland

ABSTRACTA distributed hydrological model (WaSiM-ETH) was applied to a mesoscale catchment to investigate natural flood management as a nonstructural approach to tackle flood risks from climate change. Peak flows were modelled using climate projections (UKCP09) combined with afforestation-based land-use change options. A significant increase in peak flows was modelled from climate change. Afforestation could reduce some of the increased flow, with greatest benefit from coniferous afforestation, especially replacing lowland farmland. Nevertheless, large-scale woodland expansion was required to maintain peak flows similar to present and beneficial effects were significantly reduced for larger “winter-type” extreme floods. Afforestation was also modelled to increase low-flow risks. Land-use scenarios showed catchment-scale trade-offs across multiple objectives meant “optimal” flood risk solutions were unlikely, especially for afforestation replacing lowland farmland. Hence, combined structural/nonstructural measures may be required in such situations, with integrated catchment management to synergize multiple objectives.

PESFOR-W: Improving the design and environmental effectiveness of woodlands for water Payments for Ecosystem Services

The EU Water Framework Directive aims to ensure restoration of Europe’s water bodies to “good ecological status” by 2027. Many Member States will struggle to meet this target, with around half of EU river catchments currently reporting below standard water quality. Diffuse pollution from agriculture represents a major pressure, affecting over 90% of river basins. Accumulating evidence shows that recent improvements to agricultural practices are benefiting water quality but in many cases will be insufficient to achieve WFD objectives. There is growing support for land use change to help bridge the gap, with a particular focus on targeted tree planting to intercept and reduce the delivery of diffuse pollutants to water. This form of integrated catchment management offers multiple benefits to society but a significant cost to landowners and managers. New economic instruments, in combination with spatial targeting, need to be developed to ensure cost effective solutions – including tree planting for water benefits - are realised. Payments for Ecosystem Services (PES) are flexible, incentive-based mechanisms that could play an important role in promoting land use change to deliver water quality targets. The PESFOR-W COST Action will consolidate learning from existing woodlands for water PES schemes in Europe and help standardize approaches to evaluating the environmental effectiveness and cost-effectiveness of woodland measures. It will also create a European network through which PES schemes can be facilitated, extended and improved, for example by incorporating other ecosystem services linking with aims of the wider forests-carbon policy nexus.

Water matters: An assessment of opinion on water management and community engagement in the Republic of Ireland and the United Kingdom.

Internationally, water management is moving from the traditional top-down approach to more integrated initiatives focussing on community-led action. With inadequacies in previous engagement initiatives undertaken through the first cycle of River Basin Management Planning for the EU Water Framework Directive (WFD), the Republic of Ireland has only recently embraced this bottom-up approach. The attempted introduction of national charging for domestic water use in 2015 has resulted in significant public disquiet and protest movements against the national government. In April 2015 we undertook a survey of current opinion on water management and community engagement initiatives in the Republic of Ireland and the United Kingdom. A total of 520 survey responses identified that although freshwater bodies are important in peoples’ lives, respondents were typically unaware of global initiatives such as Integrated Water Resources Management and Integrated Catchment Management. Overall, 81% of respondents did not feel included in decisions about their water environment despite an overwhelming 95% believing that local communities should have a say in how the water environment is managed. However, only 35.1% of respondents stated that they would be willing to attend local water management engagement initiatives. Rather than supporting individual gain, respondents identified social gains for the local community as avenues for increasing local involvement in water initiatives. In the Republic of Ireland, a water engagement initiative that implements the national framework local delivery model should be developed and implemented. This would 1) contribute to the second round of WFD River Basin Management Planning; 2) facilitate stronger connections between local communities and their water environment; and 3) foster bottom-up initiatives that empower communities regarding local water management issues.

Catchment metabolism: Integrating natural capital in the asset management portfolio of the water sector

The policy of the water sector demands integrated and resilient asset management. The majority of current research focuses on urban or community asset systems. To provide a fully integrated approach, one needs to delineate the focus of asset management at a catchment scale, to include the natural capital. The research described in this paper introduces such an approach, with the Environmental Regional Input-Output (E-RIO) analysis at its core.The novelty of the work is the conceptualisation of a catchment as a complex asset system, comprising of multiple subsystems. This expands the application of Industrial Ecology and functional modelling techniques in Integrated Catchment Management and Water Accounting. The Catchment Metabolism modelling schema created in this paper serves asset, water resources and catchment management purposes. The schema forms the grounds for structured collaboration among experts for integrated water resources planning and decision-making. In this paper the process of creating the modelling schema along with the techniques used are presented. A ‘live’ industrial example from the UK water sector (Poole Harbour Catchment) is used to demonstrate its application.

Modelling macroinvertebrate and fish biotic indices: From reaches to entire river networks

We modelled three macroinvertebrate (IASPT, EPT number of families and LIFE) and one fish (percentage of salmonid biomass) biotic indices to river networks draining a large region (110,000km2) placed in Northern and Eastern Spain. Models were developed using Random Forest and 26 predictor variables (19 predictors to model macroinvertebrate indices and 22 predictors to model the fish index). Predictor variables were related with different environmental characteristics (water quality, physical habitat characteristics, hydrology, topography, geology and human pressures). The importance and effect of predictors on the 4 biotic indices was evaluated with the IncNodePurity index and partial dependence plots, respectively. Results indicated that the spatial variability of macroinvertebrate and fish indices were mostly dependent on the same environmental variables. They decreased in river reaches affected by high mean annual nitrate concentration (>4mg/l) and temperature (>12°C), with low flow water velocity (<0.4m/s) and aquatic plant communities being dominated by macrophytes. These indices were higher in the Atlantic region than in the Mediterranean. This study provides a continuous image of river biological communities used as indicators, which turns very useful to identify the main sources of change in the ecological status of water bodies and assist both, the integrated catchment management and the identification of river reaches for recovery.

Working across scales in integrated catchment management: lessons learned for adaptive water governance from regional experiences

Integrated Catchment Management (ICM) has in recent years been promoted by a wealth of “top-down” government policies, while a number of “bottom-up” community-based initiatives have also been set up. At the same time, adaptive water governance, built around multi-level, integrative and participatory institutional arrangements, is called for in order to enhance adaptive capacity of social–ecological systems to global changes. Working across scales, aligning planning processes, and multi-actor collaboration are key issues in the linking of top-down and bottom-up ICM, hence providing insights into how adaptive water governance can work in practice. The paper presents a study of how ICM actors work across scales and reconcile national and local priorities in 15 regional experiences chosen to reflect a diversity of scales, histories and governance arrangements. It is complemented with an in-depth, illustrative example, taken from the Tweed River Basin in Scotland, where a local charity has gradually developed and helped bridge gaps between local communities and government. Research results present the ways in which “trusted intermediaries” can successfully close the gap across levels of governance, i.e. between communities, business, and governmental interests at multiple scales. Local “trusted intermediaries” perform well, with their local knowledge, at building rapport with key actors and effectuate change on the ground. The research also indicates the need for a legal framework, or at least an established policy structure, that acts to harness the good will and interests of local actors while improving implementation of broader, national objectives. There appears to be no specific mechanism for multi-level collaboration, although results indicate that more formal and coercive forms of partnership are necessary at later stages to ensure implementation, for example, via the establishment of formal duties on public bodies or legally binding agreements between ICM stakeholders.