Payment for Outcomes: visiting farms to determine possible sites for Natural Flood Management

iCASP is working on a project to integrate Natural Flood Management (NFM) into the National Trust’s ‘Payment for Outcomes’ trial. The Trust are undertaking the trial on some of their tenanted farms working with the Yorkshire Dales National Park Authority and Yorkshire Dales Rivers Trust. Their work will help to inform Defra’s new Environmental Land Management Schemes (ELMS). It seeks to pay for farmers for the environmental outcomes they achieve on land they farm.

The iCASP project is focused on identifying opportunities for NFM measures and discussing with farmers how NFM could fit into a payment scheme that would make business sense for them. These valuable insights will help inform future payment schemes which focus on payment for outcomes.

iCASP produced maps of each farm showing the  parcels of land tenanted from the National Trust. The land parcels were overlaid on to maps, produced from SCIMAP. These maps show areas of risk related to diffuse pollution (e.g., fine grained sediment) and the connectivity of overland flow of water to the main channel network – together, these maps show which areas of land could benefit from further management. This allows us to generate ‘opportunity maps’ that indicate where NFM interventions might best be sited; for example installation of a leaky dam in a particular location might work well to slow peak flows of water or buffer strips to help reduce sediment (soil) being washed away.

Maps of a land parcel showing the key diffuse pollution risk areas and overland water flows (left hand map shows areas of erosion risk with red areas showing higher risk than orange and yellow areas, the right hand map shows hydrological connectivity with the darkest blue showing the greatest areas of connectivity to the main channel network). These maps are produced for each National Trust land parcel and taken on to site to allow them to be annotated with notes based on what is observed on the ground and while talking the tenant farmers

Ground-truthing of the map outputs is crucial to understand the farm in more detail to ensure NFM opportunities are placed in the correct locations. For example, smaller flow pathways that connect sediment and water to the main channels, may not have been picked up during the modelling due to the resolution of data used. Speaking to the land owner is vital at this point to understand how the land is currently used and managed and where there are current issues (e.g., waterlogged soil). This is another layer of information that can be used to ground-truth the modelling output and also verify the locations of potential NFM interventions.

We have recently visited five farms taking part in the trial to do this ground-truthing. This has meant we’ve been able to annotate all the maps to verify the modelling output. This has allowed us to come up with a better understanding of which NFM interventions could be used and their locations on the farms.

A photo of the field shown in the maps above. This is looking towards where the highest levels of overland water flow were indicated by the mapping, however locating NFM measures below this was not felt to be worthwhile in this particular case because the ground below was very boggy and was already acting to slow the flow of water downhill by retaining it.

The next step in this process will be to meet with all the farmers and other organisations involved in the project to share the knowledge gained by the process and produce final maps of the suggested interventions. Meeting with the farmers will also provide valuable feedback on the opinions of NFM, which interventions the farmers would be willing to install on their land and how these efforts might be incorporated into a payment scheme that pays the farmer for the environmental benefits they produce by installing NFM. iCASP will feed the key points of these discussions to DEFRA to inform the development of ELMS as well as share this useful insight with other projects looking at payment for outcomes (e.g. the Horizon 2020 CONSOLE project iCASP is part of). The National Trust will use the insights evaluate how NFM could be incorporated into their Payment for Outcomes trial.

 

Modelling to support optimal location of flood measures

This October is the 3rd anniversary of the Calderdale Flood Action Plan (FAP) . You can find out more about who is involved with delivering the plan, the various pieces of work being undertaken and get an idea of the costs and the benefits of work already carried out through infographics produced to highlight key actions and work so far

Infographic about Natural Flood Management work as part of the Calderdale Flood Action Plan (from https://eyeoncalderdale.com/fap-3rd-anniversary)

iCASP academics been involved with work in Calderdale that aims to reduce the flow of water through the catchment using Natural Flood Management (NFM) measures. The iCASP project has been using a rain-fall run-off model, SD-TOPMODEL, to help with identifying which areas of 3 sub-catchments of the Upper Calder River contribute most to peak flows. Understanding which parts of a catchment are contributing most to flooding in the lower valley make it easier to assess the impact of locating an NFM measure in one place rather than another and allow prioritisation of those measures that will have greatest benefits.

The model produces maps like the one below that shows the speed at which water is flowing and uses rainfall data from nearby weather stations and high resolution terrain data. This modelling is combined with on-the-ground visits and meetings with landowners, land managers and flood risk managers to get the fullest picture of what is going on across the landscape when it rains.

SD-TOPMODEL output showing the baseline modelling for the Jumble Hole catchment

The modelling and site visits improve understanding of what contributions existing landscape features already make;  for example hedges and walls can help slow the flow of water across the land and by acting as a temporary store help reduce the peak flows of water. These aspects can then be included to further improve the representation of these features in the model. The modelling and site visits also allow experts to identify where in the landscape new NFM features can be located to further slow and store water.

At a meeting in November the modelling results will be presented to all the partners working on flood measures in Calderdale. From these results a handbook will be created to assist land owners in targeting appropriate NFM interventions, and to further understand how the whole catchment responds during flood events.

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

Natural flood management in the media

This week has seen the 12th anniversary of the 2007 floods which impacted across swathes of the UK and affected villages, towns and cities across Yorkshire. It is timely to look at some of the measures put in place since then to alleviate flooding in the future. Natural flood management (NFM) has had some coverage in the media recently with both the BBC and ITV reporting stories that cover activities iCASP projects are supporting.

Countryfile recently visited Hardcastle Crags near to Hebden Bridge to find out more about leaky dams and how they will help tackle flooding in the future. The NFM work in Hardcastle is as a direct result of the 2015 Boxing Day floods. iCASP has been working with the Environment Agency, JBA and the Yorkshire Dales Rivers Trust, amongst others, on monitoring and measuring the range of benefits of NFM measures such as the leaky dams seen in the programme. The main focus of iCASP’s work has been developing approaches to measure whether or not the dams work to deliver flood alleviation. A future focus of the work will be to help quantify the additional benefits of these types of interventions – such as more varied habitat for wildlife, improved water quality and enhanced well-being for visitors to the area – which will be vital for making the business case for future natural flood management measures.  Find out more about the Hardcastle Crags leaky dams from Countryfile

Images of leaky dams and volunteers by Slow The Flow Calderdale

Natural flood management encompasses a range of different measures, not just leaky dams. An ITV news report on tree planting in Hebden Bridge mentioned how this work will draw upon the expertise of iCASP later in the year to understand the impact of trees already planted. iCASP will be working on the project to help identify how features, such as trees and hedges, can absorb heavy rainfall and contribute to alleviating flooding, as well as investigating how different soil types and land covers also contribute to flooding. Decisions on where trees and hedges should be planted in the future, for optimal benefit, will be informed by a rainfall-runoff model developed at the University of Leeds.  Read the ITV report

These NFM activities rely upon a range of different partners getting involved. A diagram showing the range of different partner organisations, drawing from the voluntary, charitable, private, public and regulatory sectors, has been developed to give a flavour of the interactions in these activities in the Calderdale area.  View the interactive diagram

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.

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