Robinwood Project

Hydrogeology

Report for Wales

Tim Pagella, Brian Reynolds, David Norris, Morag McDonald

and Fergus Sinclair

Wales - interconnected problems

• increased flooding – more sparsely distributed smaller floods

• increased soil erosion– emerging problem associated with

intensification of land use

• threats to ecological status of freshwater ecosystems

– particularly through diffuse pollution

Influenced by:

• the extent of water infiltration and surface flow, in turn influenced by:

• land use practice and tree cover, • all of which are likely to change in response

to: – reform of the CAP, – conversion to CCF and from conifer to broadleaf– reversion of 10-15% forest to open areas, and – implementation of the WFD

Land use mosaics

• forest areas interact strongly with agriculture at a catchment scale

• many Welsh catchments are mosaics of land use

Anecdotal evidence that drainage of wetland for afforestation and agricultural improvement, combined with heavy grazing pressures, has reduced water retention in the landscape causing flash floods.

(b) Infiltration rate for different transect positions in grazed (G) and planted (P) areas

G 5m G 1m P 1m P 5mMe

an

co

nst

an

t in

filtr

atio

n r

ate

(cm

/h)

0

20

40

60

80

Carroll et al., 2004

trees + sheepsheep trees

The experimental site - Pontbren

Pontbren is a ‘grass-roots’ initiative involving 10 hill farms and over 1000 ha of agriculturally improved pasture and woodland in the Welsh Borders (in the upper Severn catchment)

The farmers are working for a more sustainable approach to upland agriculture

Participation at Pontbren - FRMRC

Farmers observations that trees promote infiltration have been validated – their participation in research is vital

Such interventions impact flood risk but also other farm & landscape components, so decisions to adopt are complex

Various stakeholders (farmers, EA, CCW, FC, wildlife trust) want landscape to provide different functions – we are developing indicators of these and models to help decide about trade-offs

Motivation, co-operation and knowledge

Livelihood functions• income / time working • freedom to decide, ease

of regulation, public esteem

• community cohesion – future generations

choose farming

Participation at Pontbren - EA

EA partnership agreement (CEH, EA, Pontbren Farmers and UWB) to monitor water quality

Participatory modelling

Water functions• maintain or improve

water quality– chemical concentrations in

river water (sheep dip, anthelmintics, nutrients)

– aquatic life (indicator species)

• more even water flow– summer & winter flows– presence of trout

First key requirement

• Effects of trees within land use mosaics on – water flow – and hence soil erosion and – the ecological status of streams and rivers.

• this would provide – data / models for developing – soft engineering solutions for tree management within

land use mosaics at a catchment scale – that can contribute to meeting requirements of the

Water Framework Directive

Second requirement

• Participatory research on the – development of integrated policy options for

managing tree cover in agricultural and forest land use mosaics.

• this would involve: – the development of tools to address stakeholder

participation (re-establishing and valuing social capital – L,M),

– managing trade-offs between different productive and environmental roles of trees (valuing env. Roles – L,M) within land use mosaics

– and spatially explicit policy implementation.

Wales – proposed subproject

Developing mechanisms for realising the value of tree management for water services (case studies for each country)– Identifying and quantifying services,

disbenefits and baselines– Valuing them for different stakeholders– Exploring mechanisms for trading-off different

values– Exploring mechanisms for payment for

watershed services