Opportunity mapping - woodland for water

Summary

The benefits of woodland creation for water are increasingly being recognised by the water regulatory authorities and others as having an important role to play in improving the condition of the water environment and meeting the objectives of the Water Framework Directive (WFD). This includes helping to reduce diffuse pollution from rural and urban sources, and restoring the condition of riparian and aquatic habitats.

Another water service provided by woodland is the ability to ‘slow the flow’ and thus help to reduce downstream flood risk. Managing the risk of flooding to householders is a major challenge for the country and one that is expected to increase in the future with climate change.

The case for woodlands for water

There is strong evidence to support woodland creation in appropriate locations to achieve water management and water quality objectives.  However, opportunities for woodland planting are constrained by many factors, not least economics. It's therefore important that planting is targeted to the most effective locations where it can best benefit society.

Opportunity mapping

Opportunity mapping has been developed to help identify these locations and promote more integrated catchment management. The method uses Geographical Information Systems (GIS) and can be applied across a range of scales, from assessing opportunities for planting at a strategic national or regional level down to the practical catchment or farm scale.

National mapping for England and Wales

The Environment Agency commissioned Forest Research to provide GIS spatial datasets and maps which identify opportunities for woodland creation to reduce diffuse pollution and flood risk across England and Wales.

These maps were used by FC England and partners to target Countryside Stewardship (CS) grant aid for woodland creation. The maps can also assist the Environment Agency and partners to target woodland planting outside CS as part of their river catchment management projects.

In Wales information on forest policy and the new Rural Development Plan support for Glastir Woodland Management and Woodland Creation is available from the Natural Resource Wales website

The national opportunity maps identify priority areas where woodland planting could deliver positive outcomes for water quality and/or flood risk management in England and Wales. The maps identify priority areas (at a scale of 1 km2) in catchments of river waterbodies at risk of failing good status due to diffuse pollutant loads (Nitrate, Phosphate, Sediment, Pesticides and Faecal Indicator Organisms); areas at risk from flooding from rivers and surface water and priority areas where runoff from soils is rapid and finally include information on constraints to woodland planting.

A report describing the methodology and data used to generate the maps (5934K) is available.

The derived spatial data is available from the Environment Agency National Customer Contact Team

National mapping for Scotland: River Tay catchment - a pilot for Scotland

Objectives
This study aimed to identify priority areas for woodland creation and the improved management of existing woodlands to reduce downstream flood risk and help restore damaged waters.

Background
The River Tay is one of fourteen Priority Catchments in Scotland identified by the Scottish Environment Protection Agency (SEPA) and partner organisations for restoration and protection. It is impacted by a number of major water issues, with over 1,300 residential and 270 non-residential properties vulnerable to flooding and 26% of river and loch water bodies currently failing to meet the required Good Ecological Status (GES) due to diffuse pollution.

How the study was conducted
A wide range of spatial datasets were accessed from partners, particularly SEPA, and used to generate a large number of maps and supporting GIS shapefiles showing priority areas for planting. The report (934k) provides a strong basis for developing and refining regional strategies, initiatives and plans to deliver new woodlands where they can best contribute to flood risk management (FRM) and Water Framework Directive (WFD) targets, in addition to generating many other benefits for society.

Regional mapping: Yorkshire and North East

In the Yorkshire and North-East region there are over 77,000 properties at significant risk of flooding and 73% of river water bodies currently failing to meet Good Ecological Status under the Water Framework Directive.

In collaboration with partners in the Environment Agency the method was refined to incorporate the most recent and appropriate spatial datasets to identify priority rural areas for woodland creation and the improved management of existing woodlands to help address these issues.

The Executive Summary gives a brief overview of the project and the key opportunities identified in the region:

The approach, data sources, methods and results are presented in the main report which includes guidance on the design principles for woodland creation to maximise benefits for water:

Regional mapping: Midlands

The Midlands Region faces a number of major water issues, with over 100,000 properties at significant risk of flooding and 85% of river water bodies currently failing to meet the target Good Ecological Status required by the WFD. The main aim of the mapping work was to identify priority areas for woodland creation and the improved management of existing woodlands to help address these issues.

A wide range of spatial datasets were accessed from partners, particularly the Environment Agency, and used to generate maps and supporting GIS shapefiles showing priority areas potentially available for planting. The results provide a strong basis for developing and refining regional objectives, initiatives and projects to deliver new woodlands where they can best contribute to flood risk management and meeting WFD targets, in addition to generating many other benefits for society.

The Midlands report also summarises ongoing and new case studies on woodland benefits for water, considers developments in hydraulic modelling and provides a methodology for monitoring and measuring the short and long-term effects of woodland creation on water. Guidance is provided on the design principles for woodland creation to maximise benefits for water.

The Executive summary gives a brief overview:

Catchment mapping: River Derwent

There is a long history of flooding in the Derwent catchment in Cumbria, with the most recent event being in November 2009 when the towns of Keswick, Cockermouth and Workington suffered a major flood. It's becoming increasingly clear that the problem of flooding can no longer be solved by building ever higher flood defences and instead greater emphasis needs to be given to working with natural processes to ‘slow the flow’ and increase flood storage within upstream catchments. The main aim of this mapping application was to use GIS datasets to identify areas within the catchment where the creation or expansion of woodland could help to reduce downstream flood risk.

Catchment mapping: Lake District National Park

The standing water habitats of the Lake District National Park are of international importance for their ecological, aesthetic, recreational and cultural value, and many have been designated as Sites of Special Scientific Interest (SSSI), Special Areas of Conservation (SAC) and/or National Nature Reserves. These waters are very vulnerable to disturbance and highly sensitive to pollution. The condition of many sites is unfavourable and declining due to diffuse pollution from sediment and phosphate. The main aim of this work was to assess opportunities for woodland creation to help manage erosion and nutrient enrichment problems within the National Park by targeting the main sources of pollutants and the pathways by which they are delivered to watercourses.