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Channel banks can contribute a significant proportion of fine‐grained (<63 μm) sediment to rivers, thereby also contributing to riverine total particulate phosphorus loads. Improving water quality through better agricultural practices alone can be difficult since the contributions from non‐agricultural sources, including channel banks, can generate a 'spatial mismatch' between the efficacy of best management applied on farms and the likelihood of meeting environmental objectives. Our study undertook a reconnaissance survey (n = 76 sites each with 3 profiles sampled) to determine the total phosphorus (TP) concentrations of channel banks across England and to determine if TP content can be predicted using readily accessible secondary data. TP concentrations in adjacent field topsoils, local soil soil type/texture and geological parent material were examined as potential predictors of bank TP. Carbon and nitrogen content were also analysed to explore the impacts of organic matter content on measured TP concentrations. The results suggest that channel bank TP concentrations are primarily controlled by parent material rather than P additions to adjacent topsoils through fertilizer and organic matter inputs, but significant local variability in concentrations prevents the prediction of bank TP content using mapped soil type or geology. A median TP concentration of 873 mg kg−1 was calculated for the middle section of the sampled channel bank profiles, with a 25th percentile of 675 mg kg−1, and 75th percentile of 1159 mg kg−1. Using these concentrations and, in comparison with previously published estimates, the estimated number of inland WFD waterbodies in England for which channel bank erosion contributes >20% of the riverine total PP load increased from 15 to 25 (corresponding range of 17–35 using the 25th and 75th percentiles of measured TP concentrations). Collectively, these 25 waterbodies account for 0.2% of the total inland WFD waterbody area comprising England. [ABSTRACT FROM AUTHOR]

Flow–ecology relationships within river systems are an important area of ongoing investigation, because of potential applications such as understanding the ecological impact of flow alteration at modified sites. This study analyses relationships between flow characteristics and benthic macroinvertebrates from 18 streams of similar size and typology within Northern England, to develop quantitative flow–ecology relationships applicable at regional scale. High and low flow event frequencies displayed statistically significant relationships with the ecological metrics of LIFE Score, Shannon's Diversity and a velocity flow affinity trait score. Results suggest that flow event frequencies have a significant role in influencing ecology within the river network system. Hence, this indicates that future flow regime design in the region may be enhanced if this variable is considered. [ABSTRACT FROM AUTHOR]

Beavers can profoundly alter riparian environments, most conspicuously by creating dams and wetlands. Eurasian beaver (Castor fiber) populations are increasing and it has been suggested they could play a role in the provision of multiple ecosystem services, including natural flood management. Research at different scales, in contrasting ecosystems is required to establish to what extent beavers can impact on flood regimes. Therefore, this study determines whether flow regimes and flow responses to storm events were altered following the building of beaver dams and whether a flow attenuation effect could be significantly attributed to beaver activity. Four sites were monitored where beavers have been reintroduced in England. Continuous monitoring of hydrology, before and after beaver impacts, was undertaken on streams where beavers built sequences of dams. Stream orders ranged from 2nd to 4th, in both agricultural and forest‐dominated catchments. Analysis of >1000 storm events, across four sites showed an overall trend of reduced total stormflow, increased peak rainfall to peak flow lag times and reduced peak flows, all suggesting flow attenuation, following beaver impacts. Additionally, reduced high flow to low flow ratios indicated that flow regimes were overall becoming less "flashy" following beaver reintroduction. Statistical analysis, showed the effect of beaver to be statistically significant in reducing peak flows with estimated overall reductions in peak flows from −0.359 to −0.065 m3 s−1 across sites. Analysis showed spatial and temporal variability in the hydrological response to beaver between sites, depending on the level of impact and seasonality. Critically, the effect of beavers in reducing peak flows persists for the largest storms monitored, showing that even in wet conditions, beaver dams can attenuate average flood flows by up to ca. 60%. This research indicates that beavers could play a role in delivering natural flood management. [ABSTRACT FROM AUTHOR]

Erosion and the impacts of the redistribution of sediment are a serious threat to the quality of water resources. They cause losses and/or additional expenses in many areas, such as water treatment, biodiversity or fisheries. The implementation of catchment management measures, aimed at preventing the transfer of sediment to rivers, can be a cost-beneficial way to address the problem. In order to select the measures and appropriate locations for erosion control, the spatially distributed soil erosion and sediment delivery model WaTEM-SEDEM was used. The model was calibrated against total suspended solids data at the outlet of the Wey catchment, South-east England, yielding satisfactory results. Different scenarios of catchment management were modelled to reduce the amount of sediment transported to the river. Scenarios introducing 24 retention ponds, 50-m-wide buffer strips and cover crops in areas with the largest erosion and sediment delivery were tested. The largest decrease in both sediment production and sediment export was obtained using cover crops, with reductions of 13.4% and 14.1%, respectively. A cost-benefit analysis considering multiple ecosystem services (e.g. control of erosion rates, attenuation of mass flow, pest control, wildlife and its outputs) identified the cover crops as the most cost-beneficial measure and a possible funding scheme based on payments for ecosystem services was developed as a way to enable its implementation. [ABSTRACT FROM AUTHOR]

Globally, flood frequency has increased over the last three decades. Natural Flood Management (NFM) is considered a progressive holistic flood management approach, using "natural" hydrological processes to slow and store water, delivering multiple benefits including water quality, biodiversity and amenity improvements. Although there are existing evaluations of NFM, they remain insufficient for drawing conclusions as to its effectiveness at catchment scales. However, without this evidence base and because of the domination of the natural sciences in the framing and research agenda, catchment‐wide interventions have not been implemented. In acknowledging the importance of understanding and data gaps (and attempts to fill them), this paper argues that there is an opportunity to deliver NFM more widely by capitalising on widespread interest in different land and water management sectors, supported by interdisciplinary policy‐relevant research. This paper illustrates how multi‐stakeholder collaborative partnership is suited to the dynamic complexity of NFM delivery. It is proposed that, through championing NFM delivery at catchment scales and the work of established catchment partnerships in England and Wales, there is the opportunity to more widely deliver NFM as an integrated component of flood risk management. [ABSTRACT FROM AUTHOR]

Taste and odour (T&O) compounds (most commonly 2-MIB and Geosmin) in drinking water are becoming an increasingly global problem for water management. Here, the trigger(s) for 2-MIB and Geosmin production were investigated in Plas Uchaf reservoir (North Wales, UK) with detailed water sample analysis between 2015 and 2016. Historical abstraction data from this reservoir and 4 reservoirs in Somerset (England, UK) were compared statistically using Self-Organising Map (SOM) analysis. In-reservoir measurements (2015–2016) revealed an 85% reduction in ammonium from the primary external loading source led to lower 2-MIB and Geosmin concentrations, with peak concentrations of 2-MIB declining from 60 to 21 ng l−1 and Geosmin declining from 140 to 18 ng l−1. No other measured water chemistry parameter showed a significant difference between years. The SOM results support the in-reservoir findings, revealing 2-MIB and Geosmin to be associated with high ammonium relative to nitrate for all 5 reservoirs. We conclude that ammonium is key for stimulating cyanobacterial productivity and production of T&O compounds. Whilst it is well understood that adequate availability of phosphorus is required for rapid growth in cyanobacteria, and hence should still be considered in management decisions, we suggest that monitoring sources and concentrations of ammonium is key for managing T&O outbreaks in drinking water reservoirs. • An 85% decrease in NH 4 from the primary external source reduced T&O production. • Relative nutrient abundance drives productivity and correlates with T&O metabolites. • Monitoring sources and concentrations of ammonium is key for managing T&O outbreaks. • Monitoring of biomass is not always accurate for predicting T&O outbreaks. [ABSTRACT FROM AUTHOR]

Floodplain meadows support a high level of botanical diversity because the nutrient inputs from flood sediments are balanced by nutrient offtake via an annual hay harvest, leading to nutrient neutrality. This prevents a build-up of nitrogen (N) and phosphorus (P) and depletes excess nutrients, which mitigates eutrophication in catchment areas and prevents reductions of biodiversity through competitive exclusion. A replicated field trial was undertaken in floodplain meadows in central England, with the aim of comparing the nutrient offtake potential throughout the growing season with a single or a double-cut system, and determining when haymaking should occur to maximise nutrient offtake and nutritional value of the hay. Additionally, farmer perspectives were gathered to investigate the practicality of implementing a second hay cut. The results revealed that a single summer hay cut may be sufficient to balance nutrient inputs. However, a double-cut, where a second harvest replaces autumn grazing, has the potential to actively lower N and P levels, removing 8.69 g m−2 N and 0.80 g m−2 P. Maximising time between cuts in a double-cut system provides the greatest opportunity for nutrient removal. Temperature is a key driver of plant growth. The relationship between accumulated thermal time and calendar date in central England has advanced by around two weeks between 1961–1990 and 1991–2020. Delayed hay cutting under agri-environment scheme restrictions may be increasingly detrimental to botanical diversity with advancing seasons, due to lower nutrient removal under a single-cut system, and increased competitive exclusion. Taking a first cut at the mid-summer peak in offtake potential, currently 20–30 June in central England, and a second cut in the autumn offers an opportunity to deplete excess nutrients. Whilst farmers identify practical and financial concerns that may make a second cut prohibitive in some cases, this could be overcome by, e.g., demonstrating the higher-than-expected nutritional value of hay from a second cut. [Display omitted] • Haymaking on floodplain meadows facilitates removal of excess nutrients. • A double hay cut can contribute to nutrient neutrality targets. • The time of year that hay is cut determines the nutrient content potential. • Mean thermal time has advanced by two weeks since 1961–1990 in central England. • Floodplain meadow hay can add value to a nature-friendly farming enterprise. [ABSTRACT FROM AUTHOR]

The frames and approaches adopted for collaborative catchment management (CCM) by 22 host organizations in England were examined. Hosts framed and approached CCM according to their particular funding arrangements, management priorities, actor networks, attitudes toward knowledge and uncertainty, and willingness to share power and take risks. The findings support the theory of path dependency, and indicate that the majority of hosts created CCM groups that were much narrower in scope, direction, and structure than had been envisaged by government policymakers. To address this, a new national policy framework for catchment management in England is recommended that defines guiding principles for collaboration and balances the needs for clear direction and discretion in policy implementation. [ABSTRACT FROM AUTHOR]

The treatment of agriculturally polluted water to potable standards is costly for water companies. Changes in agricultural practice can reduce these costs while also meeting the objectives of European Union ( EU) environmental legislation. In this paper, the uptake of source control interventions ( SCIs) by water and sewage companies in England and Wales as a means of controlling agricultural pollution is investigated. Data were gathered using semistructured interviews with water and sewage company representatives. Interview data were processed using thematic and content analysis. Results showed that SCIs are increasingly being adopted in England and Wales. Of the four types of SCI identified, the so-called ' Liaison' type dominated. This type of intervention requires intermediary organisations with local expertise in water catchments. Differences in pollution source control between EU countries, and England and Wales are examined. Evidence indicated that ' Liaison' SCI s types may be more prevalent in countries where water supplies are privatised. [ABSTRACT FROM AUTHOR]

Improving the stimulation and management of innovation by water utilities is a key mechanism through which the challenges of securing sustainable water and wastewater services will be achieved. This paper describes the process of adopting source control interventions (SCIs) by water and sewerage companies (WaSCs) in England and Wales. SCIs can be defined as efforts by water suppliers to control agricultural pollution where it arises. To investigate differences in the extent to which SCIs have and are being adopted across all ten WaSCs in England and Wales, Rogers' five stage innovation model is used to structure and interpret results from a series of semi-structured interviews with raw water quality and catchment management personnel. Results suggest that to promote SCI innovation by WaSCs, regulation should be designed in two interdependent ways. First, regulation must generate awareness of a performance gap so as to set an agenda for change and initiate innovation. This can be achieved either through direct regulation or regulation which raises the awareness of an organisations performance gap, for example through additional monitoring. Simultaneously, regulation needs to create possibilities for implementation of innovation through enabling WaSCs to utilise SCIs where appropriate. Evidence from the research suggests that appropriate intermediary organisations can assist in this process by providing a resource of relevant and local knowledge and data. Future research should seek to characterise the factors affecting each stage in the WaSC innovation process both to confirm the conclusions of this study and to reveal more detail about various influences on innovation outcomes. [ABSTRACT FROM AUTHOR]

Abstract: Agricultural diffuse pollution is a significant contributor to water and air quality in many catchments and the need to control harmful emissions remains paramount for government policy. In England, the Demonstration Test Catchments (DTCs) have been established to provide a basis for testing on-farm mitigation measures using collaborative multi-partner research and some of this work is targeting the Hampshire Avon (∼1700km2) catchment. To help provide integrated farm advice across England and Wales, a new Excel-based tool, FARM Scale Optimisation of Pollutant Emission Reductions (FARMSCOPER), has recently been developed for characterising diffuse agricultural pollutant emissions from representative farm types and quantifying the expected impacts of control options on those losses to the environment. Against this background, this paper describes the application of FARMSCOPER in the Hampshire Avon DTC in order to assess its utility at catchment scale and the potential benefits of relevant and practical mitigation options. Spatial datasets and the Agricultural Census returns for 2009 specific to the River Avon catchment were integrated to produce a collection of representative farm types which capture the characteristics of the local physical environment, land use patterns and farm management practices. FARMSCOPER was used to estimate the annual emissions of nitrate, phosphorus, sediment, nitrous oxide, methane and ammonia for each representative farm type. The scenarios investigated comprised baseline losses with no mitigation measures implemented, current emissions using information on the present implementation of options under existing schemes and initiatives and, the maximum potential reduction possible on the basis of implementing all available and relevant options. Model outputs suggested that reductions in pollutant loads in response to the existing uptake of mitigation methods are small (e.g. 10% for phosphorus, 7% for sediment, 4% for nitrate and 5% for nitrous oxide). FARMSCOPER suggested that technically feasible pollutant reductions on the basis of the implementation of more mitigation options could be of the order of 47% for phosphorus, 66% for sediment, 22% for nitrate and 16% for nitrous oxide. This work represents the first catchment scale application of the FARMSCOPER tool. [Copyright &y& Elsevier]

Abstract: This paper investigates the implementation of governance for sustainable landscapes, based on a catchment case study in lowland England. A participatory research process, spanning six and a half years, employed formal and informal in-depth interviews, focus group work and workshop techniques with 71 stakeholders representative of a wide range of interests in the catchment. A scenario design process within a GIS framework was used as a focus for capturing the key issues and visions of the stakeholders. Two contrasting but plausible scenarios for 2020 emerged from this process; one scenario was driven by the sustainable intensification of agricultural production and world trade, the other by the enhanced protection of ecosystem services and multi-objective land use. It was clear from discussions with stakeholders that the mechanisms for delivering an integrated approach to landscape management are not currently in place, although there have been some policy successes that could be built upon. There is also a need for new approaches to land tenure which include tax incentives and improved forms of cooperation and leadership in both policy and contiguous landscape stewardship. The methodology itself was appreciated by the stakeholders who found it useful to think more holistically. In addition, the study demonstrates an approach that individual practitioners and researchers can develop the skills to implement. [Copyright &y& Elsevier]

Accessible sediment provenance information is highly desirable for guiding targeted interventions for reducing excess diffuse agricultural sediment losses to water. Conventional sediment source fingerprinting methods can provide this information, but at high cost, thereby limiting their widespread application for catchment management. The use of sediment colour measured using an office document scanner represents an easy, fast, and inexpensive alternative method to trace sediment sources. However, the potential for poor source discrimination and its non-conservatism due to enrichment in sediment organic matter content during sediment transport represent possible limitations to its use. As such, the treatment of samples using hydrogen peroxide to remove organic matter can potentially improve source discrimination based upon geology or soil type, and the mapping of differences in colour between source and sediment samples removing the need for a priori source groups, were trialled in a new colour-based tracing framework. The River Avon in southwest England and Holbeck/Wath Beck in northeast England were studied as they have been identified as being of high priority for the targeting of on-farm advice delivered through a long-running agri-environment initiative. In both catchments, colour was effective at identifying that a small proportion of each which would be considered as being low erosion risk was the dominant source of the sampled sediment. This was due to poor connectivity between fields deemed to be at high risk of erosion and stream channels. The hydrogen peroxide sample treatment confirmed that sediment colour was not significantly altered by enrichment in organic matter content. This treament and the mapped comparison between source and suspended sediment colour improved source discrimination allowing for the more spatially-refined identification of critical sediment source areas. It is argued that this new inexpensive procedure can potentially deliver more precise and reliable information to catchment managers than costly quantitative sediment source fingerprinting methods. This method can greatly increase the availability of catchment-specific sediment source data and therefore the robust targeting of management efforts on a national scale. • Colour was effective at tracing sediment sources in both catchments. • Hydrogen peroxide treatment significantly improved source discrimination. • Sediment losses were from a small part of each catchment with a low erosion risk. • The proposed method can out perform quantiative fingerprinting methods. • The inexpensively generated data can improve catchment management support. [ABSTRACT FROM AUTHOR]

Diffuse pollution poses a threat to water quality and results in the need for treatment for potable water supplies which can prove costly. Within the Yorkshire region, UK, nitrates, pesticides and water colour present particular treatment problems. Catchment management techniques offer an alternative to 'end of pipe' solutions and allow resources to be targeted to the most polluting areas. This project has attempted to identify such areas using GIS based modelling approaches in catchments where water quality data were available. As no model exists to predict water colour a model was created using an MCE method which is capable of predicting colour concentrations at the catchment scale. CatchIS was used to predict pesticide and nitrate N concentrations and was found to be generally capable of reliably predicting nitrate N loads at the catchment scale. The pesticides results did not match the historic data possibly due to problems with the historic pesticide data and temporal and spatially variability in pesticide usage. The use of these models can be extended to predict water quality problems in catchments where water quality data are unavailable and highlight areas of concern. [ABSTRACT FROM AUTHOR]

Tamar Lakes is comprised of two reservoirs, which are located in South West England and in the headwaters of River Tamar at approximately 135 m above ordnance datum. Upper Tamar Lake (UTL) is a direct feed source reservoir of potable water in North Cornwall. Immediately following completion in 1975, UTL was subject to intense blue-green algal blooms that continue to the present. These blooms create operational problems for water treatment, especially in hot-dry years. Lower Tamar Lake (LTL) was constructed as a water supply reservoir in 1819 and became obsolete following UTL coming on-line. Detailed water quality investigations over a period of some 28 years have confirmed the source of nutrient enrichment that fuels the algal blooms to be agriculturally derived, corresponding with a substantial increase in livestock farming. Associated poor land management practices, such as extensive field drainage and inappropriate slurry disposal to land, are linked with substantial elevations in organic contaminants such as ammonia, biochemical oxygen demand (BOD) and suspended solids (SS) during rainfall events. Evidence demonstrates that both reservoirs act as primary treatment lagoons, substantially reducing the worst of these pollutants and providing significant environmental gain. The implications of the Common Agricultural Policy (CAP), the Water Framework Directive (WFD) and regulatory monitoring are discussed in relation to resource management. [ABSTRACT FROM AUTHOR]

In the UK the "critical loads" approach has been used to derive maps based on the 10km × 10km national grid. However, this grid based approach is inappropriate for catchment scale management and these maps cannot be used for "stock at risk" assessments of the number of water bodies or lengths of streams in a given area that may be vulnerable to acidification. Critical loads are determined across two large river catchments in England (The Duddon) and Wales (The Glaslyn). High resolution, digital datasets are used to characterise the attributes of each subcatchment in terms of land cover, soil, geology, topography and topology. Empirical models used to examine the relationship between these attributes and critical loads indicate that the former can be used to account for significant variation in the latter. However, these relationships can vary from catchment to catchment. Thus, although this approach provides the potential for identifying sensitive surface waters on a catchment wide basis, it is likely that models will need to be parameterised on a catchment specific basis. [ABSTRACT FROM AUTHOR]

Many catchment management schemes in the UK have focussed on peatland restoration to improve ecosystem services such as carbon sequestration, water quality and biodiversity. The effect of these schemes on dissolved organic carbon (DOC) flux is critical in understanding peatland carbon budgets as well as the implications for drinking water treatment. In many catchments, however, peatland areas are not the only source of DOC, meaning that their significance at the full catchment scale is unclear. In this paper we have evaluated the importance of different land uses as sources of DOC by combining three datasets obtained from the Exe catchment, UK. The first dataset comprises a weekly monitoring record at three sites for six years, the second, a monthly monitoring record of 25 sites in the same catchment for one year, and the third, an assessment of DOC export from litter and soil carbon stocks. Our results suggest that DOC concentration significantly increased from the peaty headwaters to the mixed land-use areas (ANOVA F = 12.52, p < 0.001, df = 2), leading to higher flux estimates at the downstream sites. We present evidence for three possible explanations: firstly, that poor sampling of high flows may lead to underestimation of DOC flux, second, that there are significant sources of DOC besides the peatland headwaters, and finally, that biological- and photo-degradation decreases the influence of upstream DOC sources. Our results provide evidence both for the targeting of catchment management in peatland areas as well as the need to consider DOC from agricultural and forested areas of the catchment., (Copyright © 2019 Elsevier B.V. All rights reserved.)