Trees on the River Uck
Natural Flood Management in the
River Uck catchment, East Sussex
Sandra Manning-Jones - Project Officer

Need for Change in
Approach
• Historic management including deepening and
straightening – loss of river habitats and
species.
• Post war increased mechanisation of
agricultural practices – demand for increased
yield – land drainage.
• Widespread loss of floodplain woodland.
• Removal of hedgerows (est. loss of
200,000km).
• Widespread loss of floodplain meadows.
• Reduction in biodiversity – ecosystem services.
• Deeply incised river channel.
• Increases ‘flashy’ river characteristics.
• Led to Water Framework Directive 2000 – the
Catchment approach.

• Historic issues with flooding in Uckfield, East Sussex.
• River flooding: 2000. Surface water flooding: 2007 + 2010.
• Hard engineered solutions not cost effective or viable.
• WFD waterbody failures.
• Need for work led by Uckfield Flood forums and locals; catchment model
produced by Durham University Phd student using OVERFLOW.
• TrUck pilot project partnership formed in May 2012 between:
• Woodland Trust - Sussex Wildlife - Environment Agency. All providing different
support.
• Aims and Objectives:
• Investigate and employ Natural Flood Management approach to reduce flood
issues in Uckfield. Meet WFD objectives. Inform and engage local landowners and
stakeholders around the flooding and river health.
About us

Adur and Ouse Catchment Partnership
The Sussex Ouse WFD Projects
Flooding
Species and
Habitats
Water Quality
TrUck
(Trees on the River Uck)
Woodland Trust /
Sussex Wildlife Trust /
Environment Agency
MORPH
(Middle Ouse Restoration
of Physical Habitats)
Ouse and Adur Rivers
Trust / Environment
Agency
OUT
(Ouse Upstream Thinking)
South East Water /
Environment Agency

Natural Flood
Management
• Range of tools to help slow and store water.
• Multiple benefits: River health/wildlife/flood mitigation.
• Work with the landscape and natural processes.
• Use natural, local materials.
• Low installation costs – easy to remove.
• One of range of measures – not suited to all locations.
• On the floodplain:
• Increasing ‘roughness’ (resistance to flood flow):
• Floodplain woodland - stores and delays water, increases infiltration to
ground, leaf litter acts as sponge for water.
• Hedgerows – slow surface water runoff (upto 67%).
• Restoring connectivity between river and floodplain:
• Large Woody Dams – encouraging out of bank flow in low impact
locations (good for river health. Designed to allow fish movement and
pinned in place).
• Increasing flood spread and storage:
• Washlands (can be managed as hay meadows) – encouraged to hold
water temporarily and slowly drain.

• Targeted woodland and hedgerow
planting – surface water flow.
• Sustainable Urban Drainage
Systems (SUDS):
• Permeable paving.
• Rain gardens.
• Water efficiency measures.
• Increasing water storage:
• Scrapes + ponds.
• contour bunds and planting + other
Runoff Attenuation Features (RAFs).
• Increasing water storage in existing
woodlands in under high flow.
Benefits for wildlife and river health, meeting WFD objectives.
Wider Catchment Measures

The River Uck
sub-catchment
• Located in East Sussex, South East
England.
• Sub-catchment of the River Ouse
covering 105km².
• Over 200km of rivers and streams.
• Some designated sites and priority
habitats (High Weald AONB).
• Some arable, but predominantly
grazing.
• Changes in land management:
wide scale use of field drains and
ditches, urban and farming
floodplain development..
• ‘flashy’ catchment – it responds
rapidly to rainfall.

• Major river flooding in Uckfield in 2000.
• Urban flooding – surface water runoff.
• Town centre ‘flash floods’ in 2007 + 2010.
• Soils and topography contribute to flooding.
• Weakly permeable clay – water retentive.
• Greensand seams issue water under high ground
water.
• Rapid runoff – steep headwaters with gill woodland.
• Town design and floodplain development.
• Town centre receives water from an area of 73km².
• Channel capacity 60-70 cumecs (over 130 cumecs
recorded at Isfield in 2000).
Flooding in the Uck

• Steeper in northern section.
• 8 tributary streams – different
watershed sizes.
River Uck Landscape

• Project sought to apply outcomes of River
Uck OVERFLOW model – new hydrological
model by Nick Odoni (Durham University).
• Benefits:
• Simplified temporal, hydrological model –
calibrated to 2000 storm hydrograph.
• Allows analysis of flood impacts of NFM
measures when added to different
locations – and combinations of locations.
• Issues:
• Phd project – creators now moved on.
• Top 20 locations provided – ground
truthing – not possible to re-run.
Putting Theory into Practice

Building the Evidence
Digital Mapping and
Modelling
Local
knowledge
and
considerations
Data analysis
and reporting
Site Work +
Recommendations
Landowner +
stakeholder
engagement
Environmental
and Technical
data
Research
and
Evidence
Dissemination of
messages and
lessons

• Lots of existing work – Sussex Wildlife Trust / Sussex
Biodiversity Record Centre.

Uck woodland
• Total of 23% woodland cover.
• 58% of which is considered to be
Ancient Woodland.
• Much reduced cover in the flood
zone 53ha (12% of EA flood zone 2).

• Digital mapping software used
to identify areas to avoid, and
areas that could have potential.
• Backwater buffers around
urban areas, roads, bridges
etc.
• <70ha upstream of Uckfield.
• Further modelling work
underway.
• Monitoring:
• Difficulties with timescales.
• Working on technical
documents for baseline.
• Reports…

OART River Habitat Survey
Uck Catchment
 Good and Bad habitats
 Non Native Invasive Species
University of Sussex Ouse Project, Gill Woodlands. Margaret Pilkington

Delivery
• Working with landowners across the
catchment in key areas.
• Creation of new floodplain and other
woodland (<3ha).
• Hedgerows planted <1.5km
• Increasing woodland water storage.
• Large Woody Dam trial.
• Further plans to extend these ideas.
• Plans for combination of approaches
(planting, contour bunds, LWD etc) over
large estate within key site.
• Continued engagement with key local
landowners through targeted
workshops.

Challenges
• Time lag related with some NFM – woodland takes 20+years to become
functional.
• No land directly tied to project.
• Landowners:
• Takes time for landowners to take on board ideas and build trust.
• “Why should upstream landowners help those downstream?”
• Demand for yield in difficult market.
• Lack of land grants for large schemes…NELMS?
• Amenable landowners not always in a prime site. Have little control over
landowners instating changes that may be in ‘negative’ areas.
• Monitoring outcomes very difficult due to timescales.
• Need more detailed landscape and river data – and easy access to
exisiting datasets.
• Multiple variables and stakeholders.
• Limited funding for projects.
• Short project timescales – need for rapid results.

The Future
• Growing interest in project and NFM approach.
• Some further funding in place for next year – need
more to extend timescales.
• Continue to work in Uck using targeted engagement
– investigating potential in wider Ouse.
• Greater focus on SUDs and urban flooding.
• Monitoring and analysing data.
• Reports and recommendations.
• Planting planned next season in key locations.
• Events and workshops.
• Working with universities and others…

• www.treesontheriveruck.org.uk
• Trees on the River Uck
• Project officer: Sandra Manning-Jones
• Tel: 07795 116880
• Email: sandramanningjones@gmail.com
Contact us!

Flood flows
Multiple Variables
Water
abstraction
Historic land
management
Vegetation
cover
Designated
sites
Urban
areas
Geology
and soils
Ground
water
Landowners
Rainfall
River users
Landuse
Channel
characteristics
Water
provision
Environmental
Flow
Water
discharges
(STW)
Climate
change
Ecosystem
Services
Farm
objectives
Habitats
and
Species
Wider publicStakeholders
WFD +
other
legislation
Partner
organisations