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30th June 2022

IMPRESS: Approaches to IMProve flood and drought forecasting and warning in catchments influenced by REServoirS

IMPRESS Report Front Cover

IMPRESS investigated improved methods for forecasting of floods and droughts where these are influenced by reservoir operations. A strong capability to forecast sub-hourly river flows a week ahead for flood warning/guidance purposes has been developed by SEPA, using hydrological and hydraulic models of rivers in combination with weather model predictions of precipitation. However, the effect of reservoir operation is not well represented and this can impact adversely on the quality of flow forecasts at locations downstream of reservoirs.

Reservoir operators have developed their own procedures for managing reservoirs to meet often a primary purpose of public water supply (Scottish Water) or hydropower generation (e.g. SSE Renewables, Drax). Longer time-horizons (weeks, months, a year or more) are of greater importance to these reservoir operators. SEPA, as a water resource regulator, also wishes to extend its forecasting capability to longer lead-times and drought flows. Both SEPA and the reservoir operators have developed monitoring, modelling and forecasting capabilities aligned to their respective priorities. The IMPRESS project has identified clear benefits in sharing and jointly developing some of these capabilities at times of both flood and drought that are in the public good.

IMPRESS undertook a review of current practice, identified possible improved approaches, and made recommendations for realising benefits through partnership working and future joint programmes of work.

The research suggested the following priority activities: (i) developing a tailored reservoir routing module (with outlet structures and control rules) to work within existing modelling frameworks, (ii) formulating improved procedures for modelling catchments (across the full range of flows) with ungauged areas and influenced by reservoirs, (iii) investigating the water balance of reservoirs, supported by case studies, with benefits to drought planning for water and hydropower supply, (iv) making better use of longer (weeks to seasons) meteorological predictions in reservoir operation and drought forecasting, accounting for their uncertainty, (v) sharing of information on reservoir geometry, operation and monitoring, along with developments in river flow forecasting capability over time-horizons of hours, weeks and months.

A Road Map of activities with a 10-year vision is proposed, guided by a Reservoir Working Group and Partnership Days.

20th May 2022

Understanding the social factors influencing resilience to drought exposure in Scotland

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Climate change poses an increasing risk of drought hazards in Scotland, with those depending on Private Water Supplies particularly exposed to water scarcity. Underlying social circumstances need to be acknowledged in drought resilience policy. This project was a CREW policy fellowship aimed to improve the understanding of the social factors influencing resilience to drought exposure in Scotland in order to inform Scottish water policy. For that, the CREW policy fellows undertook a systematic international literature review on the personal, social, environmental, and institutional conversion factors that interact to either enhance or reduce people’s vulnerability to drought. Improving communication around drought hazards can help mitigate the impact these factors have on vulnerability. To help tailor communication and improve resilience for people on Private Water Supplies and more broadly for people across Scotland, these factors were aligned with three areas of drought communication: drought forecasting, drought preparedness, and drought response. A key challenge for Scotland is the national messaging around climate change impacts to water resources. Policy implications that would help improve public messaging to target these conversion factors were identified and policy recommendations made.

19th May 2022

Antimicrobial Resistance in Scotland’s Waters - Status and Solutions

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This project evaluated the current status of antimicrobial resistance (AMR) in Scotland’s waters and identified emerging monitoring approaches and potential technological solutions. The project involved a literature review and elicitation of expert opinion via the use of a questionnaire survey of academics, industry and regulatory stakeholders, and a follow-up workshop. Findings were synthesised into a policy briefing on “Technologies for monitoring and treatment of antimicrobial resistance in water” and a Policy Note on “Antimicrobial resistance in Scotland’s waters”.

There was no broad baseline understanding of the current AMR status of Scotland’s Waters. It was noted that the most cost-effective mechanism to generate a baseline understanding of AMR in Scotland’s waters was to build on existing sampling regimes and add in further sampling where specific water types weren’t already covered. A key outcome from both literature and expert elicitations was that there is little consistency of methods across studies and monitoring for AMR.  There was no consensus on the best detection method, but the most popular were cultivation methods and polymerase chain reaction (PCR)-based methods, which are more easily accessible to researchers. Diversity of approaches is needed for research purposes. However, developing some guidelines to promote complementing these diverse approaches with some consistent ones (such as specified antimicrobial susceptibility testing on isolated E. coli and detection of a specified suite of antimicrobial resistance genes) would help provide comparable reporting and better understanding of AMR in a One-Health context. Additionally, agreement and guidance would support technology developers to improve and validate new approaches – while there is a lot of research on AMR detection methods the majority is clinical rather than environmental.

A Code of Practice would be useful to define different use cases and key measurement parameters along with validation approaches. Treatment technologies can remove AMR and cost-benefit analyses are needed to compare different treatment and mitigation strategies.


9th May 2022

A review of the risks to water resources in Scotland in response to climate change

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There is “irrefutable evidence” that the global climate is changing due to human activities. Even in ‘water rich’ countries like Scotland, these changes will have implications for the future of water resources. In Scotland, changes in rainfall patterns (spatially, temporally, and seasonally), together with the frequency and magnitude of extreme weather events including flood and drought, would result in significant challenges for Scotland’s key industries including the water sector. Such changes will impact drinking water supply, energy, agriculture, economic activity, and supply chains. Although there are inherent uncertainties surrounding the climate change projections for precipitation at the global scale, and what they mean regionally for Scotland, especially in the short-term (e.g., the next 30 years), water companies in Scotland increasingly need to compare and balance the evidence relating to changes to Scotland’s climate with their medium to long term planning decisions about the way water is stored, managed, and used.

This evidence report provides a review of studies that have assessed historical and future river flow and water availability changes in Scotland, as well as evidence on how climatic, hydrological, and other catchment-based processes may influence water resource availability in the future. Recommendations for future lines of research on effects of climate change on Scotland’s water resources are made.

Some of the key findings of the review include that river flows (outflows) have increased significantly over the 1961-2010 period in Scotland. While total annual outflows in the UK may not change significantly, future seasonal projections in the UK generally show seasonal reductions in spring and summer flows, a mixed pattern in autumn flows, and small increases in winter flows.

The review highlights that there is uncertainty regarding future frequency, duration and magnitude of both droughts and floods, including their timing and spatial extent, due to the different methodologies, indices and thresholds used and different types of hazards analysed in the studies reviewed. However, there is a consensus relating to an increase across all metrics (frequency, magnitude and duration) Scotland-wide in a warming climate. In terms of droughts, in Scotland, compound hydro-hotspots (droughts and floods) are projected to occur across eastern Scotland and the Highlands and Islands, including the Loch Ness and River Tay catchments in the far future. In the 2050s, irrigation demand, especially in summer, may rise due to an increase in temperatures alongside an increase in potential evapotranspiration.

26th April 2022

Assessing climate change impacts on the water quality of Scottish standing waters


Scotland, like the rest of the world and UK as a whole, is facing an unprecedented climate change crisis. Amongst other impacts, this is affecting the quality of its standing waters such a lochs and reservoirs. The recent UK Climate Change Committee (2022) Report to Scottish Parliament makes clear that ‘Scotland lacks effective monitoring and evaluation systems meaning that changes in aspects of many climate-related risks are largely unknown’. There is now an urgent need for evidence to evaluate climate change impacts to inform fit for purpose mitigation/adaptation strategies that can be created and implemented in Scotland without delay. These will safeguard the integrity, biodiversity and sustainable use of the water environment, for people and for nature.

The overall aim of this project was to compile and assess the key evidence available to improve our understanding of climate change impacts on the water quality of Scottish standing waters at national, regional and local scales. The project focused on the interactions between climate change, the drivers of eutrophication problems and their impacts. We synthesised information from the literature, expert opinion and monitoring data, and used statistical analyses and visualisation (mainly mapping) combined with climate change scenario modelling to address six strategic water research questions.

The key findings were that:

  • Climate change is affecting the water quality of Scottish standing waters, specifically in relation to algal blooms, at multiple scales; mostly through increases in air temperatures and changes in rainfall patterns.
  • Increases in Scottish loch and reservoir temperatures are closely related to changes in air temperatures; rapid and extensive climate change-driven warming of these standing waters has already occurred in recent years and is expected to continue increasing.
  • Water temperature increases in many lochs and reservoirs have already been recorded; standing waters are projected to get warmer in the south and east of Scotland but this climate-related risk will spread further and reach all parts of Scotland by 2040.
  • Climate change will increase the risk of algal blooms developing in Scottish lochs and reservoirs – especially potentially harmful cyanobacteria.
  • Increases in algal blooms are often associated with a higher risk of potentially harmful toxins from cyanobacteria being released into the water; the likelihood of this occurring will increase with warmer temperatures and lower flushing rates.
  • Currently, all types of Scottish standing waters in all areas and locations are at high risk of climate change impacts.
  • Different types of lochs and reservoirs will respond differently to climate change impacts, with some more likely to develop water quality issues than others.
  • Water temperatures across different types of lochs and reservoirs are already warming in most places; this climate-driven trend is projected to further increase from south to north, with an exacerbated water temperature situation expanding to all parts of Scotland by 2040.
  • Climate change driven increases in water temperature and nutrient availability, and reductions in flushing rates, will increase the risk of water quality issues developing in Scottish lochs and reservoirs.
  • Scottish loch and reservoir sensitivity factors will affect the risk of water quality issues developing due to climate change impacts.
  • A whole system approach needs to be taken to mitigate future climate change impacts on standing waters.
  • An integrated catchment-based approach needs to be taken for setting water quality targets and planning interventions.

This project made key recommendations on changes needed to adapt water policy and existing monitoring networks as part of Scotland’s strategic and coordinated response to the climate crisis, as well as informing the research direction and future phases of work.

15th April 2022

International policy review on small sewage systems

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Private small sewage systems, such as septic tanks, if not properly managed, can lead to a number of issues including pollution of the water environment and nuisance issues such as ponding and odour. These issues can have significant negative impacts on local communities and are difficult for these communities to address. Through an international review of approaches to small sewage systems, this project sought to understand how small private sewage systems are managed in other countries (with similar socio-economic profiles to Scotland) and the benefits and disbenefits associated with different approaches, with a view to informing approaches in Scotland.The review focused in particular on policies relating to the authorisation of new and existing small sewage systems and to the ongoing regulation both ‘historic’ and newly-installed systems.

This project sought to answer the following questions:

  • What is the policy baseline on small sewage systems (SSS) in Scotland?
  • How are small sewage systems (SSS) and discharges in other countries controlled?
  • Are there examples of approaches that encourage circular use of water, energy or nutrients?

The international review outlines the commonalities in SSS related issues across countries where SSS are used and draws a serie of key recommendations for policy and management. 

The guidance document provides information for developers to enable them to identify the most appropriate sewage systems for a specific use and instil confidence to planners and the regulator that such systems are fit for purpose and suitable for private operation over the long term.

31st March 2022

Better Buffer Design, Placement and Management

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Can improved design concepts for riparian buffer measures and placement improve uptake and best practice in Scotland?

At this present time of developments in knowledge around diffuse pollution management, habitat restoration of river corridors and natural flood management, it is timely to make a synthesis of latest research with specific regard to understanding best practice in riparian zone management. So-called buffer zones alongside watercourses have potential to enhance ecosystem services in Scotland at a time of growing concerns for water quality, floods and droughts, bank-side habitat loss, condition of aquatic species and superimposed climate pressures. Yet, the majority of riparian management is basic and often mismatched to the specific needs and pressures of the site, for example not effectively targeting site-specific pollutant pathways by which runoff reaches watercourses. This CREW Policy Note examines how considering an enhanced range of designs, and targeting them to most suitable landscapes and pressures on the environment, can be achieved to improve multiple outcomes, including aspects of wider context for improving the uptake of enhanced riparian measures.

1st April 2022

Webinar: Lessons to be learned from the development of the Scottish SARS-CoV-2 wastewater screening programme

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As part of an ongoing CREW project to detect SARS-CoV-2 variants in wastewaters, a webinar will take place on Wednesday April 27th 12.30 to 14.00 to examine the lessons learned from the development of the SARS-CoV-2 wastewater screening programme in Scotland.

Lessons to be learned from the development of the Scottish SARS-CoV-2 wastewater screening programme

The Scottish Environment Protection Agency (SEPA), together with Scottish Water, have been monitoring the levels of SARS-CoV-2, the causative agent for COVID-19, in wastewater across Scotland since mid-2020 to provide an overview of the epidemic and to inform health boards and policy makers. Funding from the Scottish Government’s Strategic Research Programme, managed by CREW, has played a key role in establishing the programme.

As part of an ongoing CREW project to detect SARS-CoV-2 variants in wastewaters, a webinar will take place on Wednesday April 27th 12.30 to 14.00 to examine the lessons learned from the development of the SARS-CoV-2 wastewater screening programme in Scotland.

The webinar will be introduced by Professor Andrew Millar, former Scottish Government CSA ENRA and include short presentations from Dr Isabel Fletcher and Professor Catherine Lyall of the University of Edinburgh. As part of this event, researchers will share learning on how to be more prepared for rapid response collaborative research in future crises. There will be a Q&A session and an optional opportunity for informal discussion at the end of the event.

If you wish to attend this event, please register on Eventbrite here.

30th March 2022

Environmentally informed pharmaceutical prescribing in Scotland

The prescription of pharmaceuticals is the most commonly used healthcare intervention and indisputably has an important role to play in human health. However, pharmaceuticals can have negative effects on the environment and living organisms. Firstly, pharmaceutical use significantly contributes to the healthcare sector’s carbon emissions. Secondly, pharmaceutical residues from human excretions and improper disposal of unused medicines can enter the water environment through wastewater and endanger aquatic life. Thirdly, pharmaceutical substances in the environment are thought to contribute to the global threat of antimicrobial resistance.

Often, a choice of pharmaceutical options is available to prescribers with decisions informed by therapeutic benefit, cost, and patient-related factors. To account for the environmental impacts of pharmaceuticals, environmentally informed or eco-directed prescribing proposes: 1) reducing pharmaceutical consumption as appropriate through improved rational prescribing practices; and 2) selecting medicines which have less environmental impact through the integration of environmental criteria in the development of medicine formulary. This would contribute to the sustainability of the healthcare sector and safeguard both public and planetary health.  

A joint analysis of policies on pharmaceutical prescribing and environmental monitoring of pharmaceutical substances in water environments was conducted to investigate whether the current policy landscape supports the adoption of eco-directed prescribing in the Scottish context. Barriers to and enablers for the policies and its implementation were also identified through a series of knowledge exchange activities with key actors.

Pharmaceutical pollution and the need to address this are recognised in key healthcare and environmental policies. However, barriers to the integration of environmental criteria in medicine appraisal, environmental monitoring of pharmaceutical substances, awareness of stakeholders, and coordination between key expert groups need to be resolved.

A three-pronged policy framework that should be embedded within the processes of healthcare and environmental agencies in Scotland is proposed to effectively integrate eco-directed prescribing as a joint programme of health and environmental sectors in the country. This three-pronged policy framework includes: 1) the organisation of a coordinative mechanism between key stakeholders; 2) systematic integration of environmental criteria in formulary development supported by expert evaluation of environmental risks of pharmaceuticals; and 3) improving knowledge of healthcare workers and the public on the environmental impact of medicines.


Methodology for the detection of new variants of SARS-CoV-2 in wastewater

Methodology for the detection of new variants of SARS-CoV-2 in wastewater

This project aims to develop a process for variant monitoring, and to capture, curate and report the technical outputs and organisational learning, to derive benefit from the existing investment in sampling viral material from Scottish wastewater. 

Results include:

  • Testing but rejecting PCR-based methods (qPCR, dPCR), optimising a DNA next generation sequencing method.
  • Over 2000 wastewater samples from across Scotland have been screened to monitor the spread of Omicron and then BA.2 variants between November 2021 and March 2022.
  • This method also has potential for analysing multiple pathogens simultaneously. Pilot experiments have commenced to measure influenza virus, as well as SARS-CoV-2, in wastewater.

Making the data and methods generated by the Scottish programme widely available safeguards the public investment and has been achieved by providing training on data management, and by depositing outputs on platforms to maximize visibility while assuring cost-free, long-term, sustainable preservation.

Similarly, valuable lessons may be learned from the operational processes that have developed across sectors to enable the monitoring of SARS-CoV-2 in wastewaters in Scotland. The ‘Lessons Learned’ phase is synthesising these lessons and qualitative assessment of the differences between the equivalent programmes in the 4 UK nations and internationally is continuing.

Project Objectives

The aims of the project were:

1) To provide a workable, testing process for SARS-CoV-2 (Covid-19) variants, similar to the CREW project’s contribution for SARS-CoV-2 abundance.

2) To share the outputs from the wastewater monitoring programme by Open Research methods.

3) To conduct a ‘Lessons Learned’ review from the development and management of the programme and to infer any general lessons and recommendations for Scottish Government and its agencies in delivering future, urgent programmes.


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