Tackling flooding; whole catchment approaches

At times when we experience floods, such as those currently devastating people’s homes and businesses in parts of Yorkshire, Derbyshire and Nottinghamshire, it is very common to see people attempting to distill the problem down to a single cause. In complex hydrological systems there is no sense in taking this simplistic approach; rather the whole catchment needs to be considered and we need to think about how we make entire catchments more resilient to extreme events. This is one reason for the ’i‘ in the NERC-funded Yorkshire Integrated Catchment Solutions Programme (iCASP). We work on the understanding that what happens in one area of the catchment affects other parts of the catchment because it is a whole system.

Our work looks at how processes integrate across the entire catchment and while finding solutions to environmental problems we also seek ways to address multiple problems at once, thereby delivering value for money. It isn’t just physical elements of catchment management, there’s a human element too: we work closely with partners and stakeholders on all projects to build relationships and trust and to support organisations to work together in confidence to maximise beneficial outcomes.

Flood Forecasting, and Drought & Flood Risk Mitigation are two of our six workstreams that determine the work we fund. We draw upon the research of several universities in the region including the University of Leeds, University of Sheffield and the University of York to address problems that organisations across Yorkshire are seeking to tackle. This ranges from trying to improve the ability of local councils to respond to weather forecasts by improving the advice provided in a forecast, or implementing measures that slow the flow of water across the landscape so it takes longer to move into the rivers and doesn’t contribute to sudden peak flows.

Restoring functionality

Restoring the peatland in the upper reaches of a catchment means that rainfall there takes longer to move through and into rivers downstream. Our Peatland Restoration project has developed guidance for practitioners and managers to help their decision-making as to the best restoration techniques to return the system to its normal functionality of water storage and slowing downstream flow. An added benefit of this kind of restoration is that functioning peatland acts as a sink/store locking up carbon that might otherwise be driving climate change.

Images of Sphagnum in peatland

Natural Flood Management: modelling, mapping and monitoring

Several of our other projects are on the same theme as this: using natural processes to slow and store water moving through the landscape to avoid the mass flows and peaks that cause problems. There are many Natural Flood Management (NFM) pilot projects throughout Yorkshire funded by government. Our iCASP projects are supporting these by working with partner organisations to develop modelling, mapping and monitoring capability.

We use computer models to understand which parts of a catchment contribute greater quantities of water into a watercourse than other parts, and to understand the role that landscape features – both natural and human-made – may play in this process either slowing or storing water. Our modelling expertise is currently being used in our Calderdale NFM project to understand how three tributaries contribute to water flows further downstream.

Combining rainfall data and high resolution terrain data, combined with the knowledge gained from site visits means we can create ‘Opportunity Maps’ that allow an identification of what the current landscape management means for flood risk and what might be done in future.

Once developed, Opportunity Maps allow us to identify locations where NFM interventions such as tree planting, aerating soil, buffer strips or leaky dams may best be sited for maximum effect. In the case of our Don Catchment project, we work with the land managers to identify which interventions could be installed by volunteers, what interventions would be best and where our mapping allows us to identify the additional impacts these interventions may play. Many NFM interventions can serve multiple purposes; they may not only slow down the flow of water across the landscape, but they might also improve water quality or provide valuable habitat for wildlife, contributing to improved biodiversity and species richness in an area.

“We feel very privileged to have benefited from our involvement in iCASP, as it has given us access to expertise that has resulted in opportunity maps that are guiding our decision-making in relation to our Hidden Heritage Secret Stream (HHSS) project. These maps identify locations in the landscape where we can have the most impact, and they have also helped highlight the types and locations of NFM interventions that not only slow the flow of runoff, but also reduce diffuse pollution and increase ecological connectivity across the landscape. Our team is using the maps to identify sites for investigation on the ground, and they have been very useful when engaging with our partners and landowners.”

Ed Shaw, Director Don Catchment Rivers Trust

Monitoring the impact and effectiveness of NFM interventions is critical; both to being able to identify what impact is delivered, but also in being able to make the case for funding such measures and for their ongoing maintenance.  A key aim of another of our Natural Flood Management projects is to improve the monitoring capability of those using NFM so they are able to carry out rigorous monitoring to contribute to the evidence base for this kind of flood risk intervention.

In our Payment for Outcomes project we are working with the National Trust to build NFM measures into their payment for outcomes trial. Farmers on some of the Trust’s tenanted farms will receive payment for the environmental outcomes they achieve, and this work will eventually inform Defra’s new Environmental Land Management Scheme and show how NFM can be integrated within this.

To maximise all the benefits of this work, we’ve developed a Natural Flood Management Community of Practice (CoP) to bring together people working on NFM to share skills, experience and best practice, build capacity and discuss challenges and opportunities.  The CoP meetings draw upon the expertise we are deploying in the NFM projects we work on and also brings together people from across the region – and increasingly from beyond it too – to understand how best to manage their areas of land in the most appropriate ways for our future climate.

Images from the Natural Flood Management Community of Practice meeting in June 2019

Improved forecasting

Slowing the flow of water through a catchment, and the measures put in place to do this are just one aspect of the measures we are working on. As demonstrated in the last week, at times rainfall is extreme and even if there are lots of interventions in place upstream, the sheer quantity of water is overwhelming, so we also work on improving flood forecasting. Our Enhanced Surface Water Flood Forecasts project worked with a range of partners to trial new forecasting software to assess whether it helped flood risk managers and emergency responders in the decision-making processes they go through in a flood event.

In response to Defra’s Surface Water Management Action Plan, the Environment Agency and Met Office are scoping a new capability for sharing with responders very short range and rapid update forecasting (“nowcasting”) for the type of rainfall that causes surface water flooding. The Enhanced Surface Water Flood Forecasts project final report, including feedback from the incident response workshop, has provided valuable information and user response insight for the discovery phase of this project and we expect that continued engagement with the iCASP team will continue to be beneficial for understanding user needs and exploring piloting opportunities.”

Graeme Boyce, Project Executive, Flood Forecasting Centre

Our Living With Water Catchment Telemetry Integration project, which the Living with Water Partnership are undertaking in Hull, will bring together remote monitoring data of water flows carried out by several organisations with decision-making software to create a tool that will help deliver operational preparedness for events such as those we have seen in the last week and identify optimal locations for future monitoring. Combining such data collected by these organisations has not been done at this scale before; this way of joint working will be extremely powerful in making higher levels of knowledge available to decision makers and first responders about actions to take and deployment of flood defences.

Building resilience

Our newest project – Bridging the knowledge gap to boost SME resilience – starting later this month will be working on ways to build the resilience of the SME sector. Here in Yorkshire, much of the private sector is made up of SMEs who can be very vulnerable to flooding and the knock–on effects to the regional economy of a flood event can be significant and far-reaching. The project will work with local authorities and the insurance sector to develop a robust methodology for assessing the direct and indirect costs of floods on the SME sector so they are able to tailor their flood assessments and responses appropriately. By providing detailed information on the effectiveness of resilience measures and risk reduction activities, flood risk can be properly priced and managed by SMEs and appropriate support can be given to SMEs to make them more resilient and able to reduce their risks. Local Authorities will be better able to carry out future flood assessments, lobby for additional funds to better prepare for future flooding and, in the event of a flood, prioritise their response in a consistent and timely manner.

iCASP is also working with City of York Council on the Yorkshire Future Flood Resilience Pathfinder project to understand the current level of Property Flood Resilience (PFR) measures in place across Yorkshire, and what can be improved.

This just a snapshot of some of the work we are undertaking to produce solutions to water challenges across Yorkshire, the UK and globally. Our work extends right across catchments, from high and remote peatlands where some of the water that floods peoples’ homes begins its journey, to the streets where we live and the monitoring and forecasting that takes place to try to improve the way we respond, the advice given and the deployment of measures to reduce flood risk.

“Over time, we are increasing the number and diversifying the types of flood management techniques that will reduce peak flows downstream providing new tools to support farmers, villages, towns and cities susceptible to floods.”

Joe Holden, Director, iCASP

The environment is a complex system and we need to work at many different levels to tackle integrated problems. With climate change increasing the likelihood of extreme weather events, it is clear that we need to continue to invest in ways to address resilience and to use a wide range of solutions across the landscape to tackle flooding, rather than think about each component of the system in isolation.

Improving forecasting for surface water flooding

With much of the map of England lit up with flood warnings and alerts this morning, this serves as a timely reminder about the importance of ongoing work into flood forecasting.

Screen grab of the Gov.UK Flood Information Service

 

The recent iCASP project on Enhanced Surface Water Flood Forecasts (ESWFF) set out to try to enhance the forecasts that are issued to help decision making in the run up to, and during, a flood event. A wide range of people utilise these flood forecasts including the emergency services, flood planners in local authorities, water utilities and the Environment Agency.

The culmination of iCASP’s ESWFF project was a mock incident response workshop in April that used data from a previous flood incident to see if enhanced forecasts would lead to different decision making. Involving many different flood responders in the workshop gave useful insight into the value placed on different kinds of information, how decision makers use different pieces of information and how the information could be further improved for clarity and ease of use.

Tweets issued to warn the public about surface water flooding

 

Several recommendations came out of the project, including how to better support local authorities in their responses to surface water flooding, and further development and testing of user-centric surface water forecast information.

The executive summary, final report and a flyer about the project can all be freely downloaded:

Executive Summary (of final report)

Final Report

Flyer about the project

Improving future flood resilience

iCASP will be involved with the new ‘Yorkshire Future Flood Resilience Pathfinder’ project led by City of York Council which won Government funding last week.

The project involves several iCASP partners including City of York Council and the Environment Agency and will encourage greater uptake of property flood resilience (PFR) measures across Yorkshire. It will draw upon existing projects and initiatives tackling flooding in the region and share best practice and provide training.

One of the more exciting aspects of the project will be the creation of a physical demonstration site in the form of a community hub and learning lab at Wilberforce College, Hull. The learning lab will have exhibits, physical models and demonstration PFR measures used to deliver training and awareness raising to a broad range of other projects, communities and people.

The Living with Water Partnership, who recently started an iCASP project on telemetry integration, will co-develop the learning lab and continue its management and delivery beyond the end of the pathfinder funding.

iCASP’s role in this pathfinder project will be to review the current awareness and adoption of PFR measures in communities and businesses across Yorkshire, and also across local authorities, planners and other professionals who promote, procure, design and deliver PFR interventions. This will take place at the outset of the pathfinder in September 2019, and then be revisited towards the end of the project to understand the reach and impact the pathfinder project and its interventions have had, and to make recommendations for future work and opportunities to develop the programme further.

Other links of interest:

UK Government press release on new funding for flood resilience

Hull City Council news item on learning lab

Living with Water news item

iCASP hosting Exercise Augustus – surface water flood forecasting and response workshop

Introducing participants to the day’s activities and where the forecasts and data they will be seeing comes from

This week iCASP hosted a workshop for a range of organisations across Yorkshire involved with flood preparedness and response, and national organisations responsible for producing flood forecasts and alerts. The workshop was run to test out how useful it could be to combine probabilistic rainfall forecasts (Met Office Global and Regional Ensemble Prediction System, MOGREPS) with high-resolution hydrodynamic modelling (JBA’s JFlow®) to provide localised surface water flood forecasts.

A mock incident response situation – Exercise Augustus – was run using JBA’s Exercise Management System (JEMS), which presented representatives from Yorkshire’s Local Authorities, flood action group leaders, Environment Agency, emergency services and Yorkshire Water with the ‘new’ forecasts based on a real flooding incident in Leeds to see how they responded to the information they were given, and what decisions and actions they would take as a result.

Screen grabs of some of the information participants were shown during Exercise Augustus

This kind of incident response scenario planning gives us an understanding of the kinds of information that incident responders find most useful in helping them make their decisions – both in advance of an incident and also as the incident is unfolding.

Participants discussing the data and information and what it means ‘on the ground’, and what decisions and actions to take as a consequence

The participants worked in four groups so that their thoughts on the information they were presented with, and the rationale for their decision-making, could be understood and captured. A report will be produced summarising the different responses of the groups that will allow iCASP partners to better understand the ways to present information to flood responders, and which kinds of information elicit the most appropriate responses to the situation.

 

 

 

 

The flood that Exercise Augustus was modelled on took place in Garforth, Leeds on August 22 2015.

Enhanced Surface Water Flood Forecasting Project

Yorkshire is prone to all sources of inland flooding: from rivers, rising groundwater, flash floods and prolonged heavy rainfall which can cause surface water flooding. Arguably flooding from rivers is more straightforward to forecast because rises in water level can be measured and seen in advance. However, in the case of rainfall, it is harder to forecast precisely where heavy prolonged rain is going to fall and therefore if that rainfall will cause surface water flooding by landing somewhere with inadequate drainage.

Up until now surface water flood forecasts have been limited to relatively coarse–scale county-level red/amber/green warnings issued by the Flood Forecasting Centre and static risk maps, which are more useful for longer term planning. The iCASP Enhanced Surface Water Flood Forecasting Project will therefore convert the latest advances in probabilistic rainfall forecasting and high-resolution surface water modelling into useful real-time forecasts to help authorities which have to react to potential flood events.

Read moreEnhanced Surface Water Flood Forecasting Project

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