Restoration of Durrow floodplain alluvial woodland, Ireland

Résumé

Summary

This site was one of nine included in the LIFE05 project to restore priority woodland habitats in Ireland. The Durrow site lies on the floodplain of the River Erkina and had been affected by planting of non-native conifers and associated drainage. A network of shallow ditches across the site was reducing the retention time of floodwaters; to counter this, c.350 ditch-dams were installed (installation 2009, LIFE05/NAT/IRL/000182). Since then, Durrow has been confirmed as part of the River Barrow & River Nore SAC (002162), where alluvial forests (91E0*) are a qualifying interest; assessments also record calcareous “petrifying springs” (7220*) within the alluvial woodland along the Erkina floodplain, and describe Durrow as one of the largest remaining alluvial woodlands in Ireland. At catchment scale, EPA WFD characterisation shows the downstream waterbody ERKINA_050 declined from Good to Moderate status with elevated phosphate and agriculture as a significant pressure, framing ongoing risks to riparian habitats. Nationally, Coillte’s LIFE05 programme restored >550 ha of priority native woodlands across nine Natura 2000 sites (including Durrow). Locally, the Durrow Biodiversity Action Plan 2023–2028 highlights the Erkina, the Nore and associated woodlands within the SAC.

Photo gallery

Vue d'ensemble
Year of issue
2025
Project
NWRM
Implementation status
Completed
Location of the project
The site is located on the floodplain of the River Erkina, which is a tributary of the River Nore, in southeast Ireland.
Country
Ireland
NUTS2 Code
Southern and Eastern
Sponge measures implemented in the case study
Floodplain restoration and management
Check dams
Objectives
Restore 95 ha of Annex I alluvial woodland.
Block 350+ drains to raise water table.
Remove non-native species across the site.
Promote regeneration of native wet woodland vegetation.
Involved partners
Authority typeAuthority nameAuthority roleCommentsAuthority responsibility
Forest ownersCoillte Teoranta [The Irish Forestry Board]ImplementationCoillte is the commercial company responsible for Irish forestry. They were responsible for the initiation and implementation of this project, based on improvements they wished to make to forests on their own land.Responsible
Nature parkNational Parks and Wildlife Service (NPWS)ImplementationCo-implementer; provided conservation expertise, monitoring, and habitat assessment.Responsible
OtherEU LIFE-NatureFinancingMain financial backer; funded restoration under EU Habitats Directive goals.Supporting
NGOWoodlands of IrelandDetermination of design details of the measureContributed ecological input and promoted traditional woodland management practices.Supporting
Private property ownersLocal stakeholders/communityOtherParticipated in awareness-raising and informal monitoring.Supporting
Site Information
Climate Zone
Cool temperate moist
Precipitation
1000.00 mm
Temperature (°C)
10.00 °C
Elevation range
87 m
Slope range
0-1%
Vegetation class
Riparian alluvial woodland dominated by native wetland species (e.g., alder, willow).
WFD Ecological status
Moderate
WFD Chemical status
Unknown
Water quality status
In sub-catchment Nore_SC_050, water body ERKINA_050 declined to Moderate status with elevated phosphate; likely pressures are agriculture and hydromorphology from drainage district works.
Design and Implementation
Project scale
Micro
Project scale specifications
The Durrow project restored 95 hectares within a larger 550.8-hectare national LIFE programme. It focused on one Natura 2000 site, indicating a site-level but impactful intervention.
Project area
95
Project area specifications
Entire area subject to hydrological and vegetative intervention (e.g., damming, planting, invasive removal).
Basis of design
Designed for seasonal water retention, not extreme storm events. Aimed to mimic natural floodplain dynamics, not meet specific engineered storm thresholds. The measures are designed to restore the alluvial woodland habitat by holding water on the floodplain for longer.
Design capacity
The measures are designed to hold back water and increase water levels in the alluvial woodland, increasing retention time on the floodplain. There is no specific design capacity.
Principles
Restoration followed EU Habitats Directive guidance, aiming to re-establish natural hydrology and native species composition in a degraded alluvial forest. The approach prioritized ecological integrity, minimal intervention where possible, and natural regeneration. Public awareness and long-term sustainability were integral to the design.
Constraints
Providing the desire/intention is to restore habitat upstream and there are no areas local to the drainage that should not be put at risk of higher water levels, there are no constraints to this type of measure.
Favourable preconditions
These measures could be applied anywhere that woodland or other habitat has been drained, although the details of the approach will vary depending on the soil type (in this case, alluvial deposits). Existing semi-natural topography, low gradient, flood-prone landscape, and remnant native vegetation enabled successful hydrological restoration.
Financing
Total cost
2595000.00 €
Costs investment information
The total LIFE project cost was 2.284 million euros, which was spread across 9 sites. No information has been obtained about the distribution between sites or the costs specifically attributable to the relevant hydrological measures.
Costs land acquisition information
No land aquisition was needed.
Costs operation maintenance information
Ongoing monitoring and maintenance was planned in an "After LIFE Conservation Plan"
Costs disposal decommissioning information
Not relevant as it is a permanent restoration.
Financing authorities
Authority nameType of fundingCommentsFinancing share
European UnionEU-funds: LIFE+EU-LIFE0550 %
CoilltePrivate funds—50 %
Compensations
Non
Compensation remarks
No compensation was required, as the land was already owned or managed by Coillte (state forestry company).
Policy and Governance
Policy description
The main driver for the work was deterioration of priority habitat, due to planting of non-native conifers and drainage. The drainage meant that floodwaters were not being retained on the floodplain.
Land ownership
Coillte Teoranta (the Irish Forestry Board) owns the Durrow alluvial woodland and implemented the works.
Policy targets
Improved Biodiversity
Target remarks
Reinstate natural hydrology. Improve floodplain biodiversity, enhance water retention, reduce flood risk, and increase public awareness. Restoration was designed around ecological and hydrological targets aligned with EU conservation obligations, while also producing co-benefits for water management.
Policy pressure
DirectiveRelevant pressure
WFD identified pressureHydromorphological degradation
WFD identified pressurePoor ecological status
Floods Directive identified pressureIncreased runoff due to drainage
Other EUHabitats Directive: Unfavourable conservation status of Annex I habitats.
Pressure remarks
Related WFD pressures include hydromorphological alterations and nutrient pressures from past land use.
Policy impact
DirectiveRelevant impact
WFD identified pressureSupports good ecological status via wetland restoration.
Floods Directive identified pressureHelps mitigate localized flood risk by restoring flood retention functions.
Other EUHabitats Directive: Contributes to Favourable Conservation Status of 91E0 habitat.
Impact remarks
Though biodiversity-focused, the project has tangible water regulation and flood prevention impacts aligned with EU water policy goals. The project directly mitigates habitat loss and altered floodplain dynamics through nature-based solutions.
Requirement directive remarks
The project meets cross-directive goals through a synergistic, site-based nature restoration strategy.
Policy challenges requirements
Managing invasive species; long-term habitat management and public engagement.
Part of a wider plan
Oui
Wider plan
Wider plan typeWider plan focusNameComments
—Environment & BiodiversityLIFE project LIFE05 NAT/IRL/000182The title of the LIFE project was "Restoring priority woodland habitats in Ireland". It covered 9 sites, with the Natural Water Retention Measure installations at one site (Durrow).
NationalEnvironment & BiodiversityNational Biodiversity Plan (Ireland)Durrow aligns with national targets for woodland recovery.
Public consultation
Oui
Consultation activities
Activity stageActivity typeComments
Implementation phaseInterpretation boardsTwo interpretation boards at Durrow
Screening phaseProject websiteSet up at project commencement and updated through the project and with final deliverables
Implementation phaseProduction of project brochuresIntroductory brochure produced early in the project, with a final results brochure on completion. Hard copies printed for dissemination locally and internationally
Implementation phaseAnnual "woodland walk"Held annual during the project duration at three demonstration sites (although Durrow was not one of them)
Screening phasePublic consultation meetingsIn total eight events in year 1, 20 in year 2, 14 in year 3 and seven in year 4
Implementation phaseEnd of project conference—
Has contractual arrangements
Non
Impacts and Monitoring

Monitoring System

Monitoring parameters
Water level monitoring in dipwells. Vegetation monitoring by quadrat surveys and aerial imagery. No monitoring in adjacent river.

Maintenance

Maintenance requirements
Ongoing control of invasive species and maintenance of dams/fences.

Impact Assessment Methodology

Performance impact assessment method
Edge of Field/Plot
Performance impact estimation information
Dipwells were installed at the start of the project, which were used to inform the requirements for measures, as a result of which coffer dams were installed on ditches. Dipwell monitoring was continued after installation. Photographic documentation is also used.
Biophysical impact assessment method
Water table monitoring and vegetation plots.

Socio-economic Impacts

Direct benefits information
Enhanced flood mitigation downstream.
Ancillary benefits information
Creation of employment through site works (damming, tree removal).
Increased eco-tourism and education via trails and interpretive signage.

Biophysical impacts: Hydrology

Hydrological effects
Restoration of seasonal inundation patterns; raised water tables; stabilized floodplain hydrology.
Information on retained water
Water is retained through blocked drains and re-wetted soils; quantified volumes not provided.
Information on runoff reduction
Qualitative reduction in runoff due to water retention by floodplain and rehydrated soils.
Information on Restoring hydraulic connection
Ditch-blocking reconnected floodplain to river hydrology, enhancing lateral water movement across site.
Information on reducing flood risks quantity
Reduced via water retention on-site, delayed runoff, and restored floodplain buffering.

Biophysical impacts: Biodiversity

Improved biodiversity
Oui
Information on improved biodiversity
Along with other measures in the project (removing non-native species), damming the ditches allows the alluvial woodland habitat to be restored.

Significant habitat restoration of Annex I alluvial woodland.
Native wet woodland species (e.g. alder, willow) recolonized.
Enhanced bird, insect, and understory flora diversity.
Specific species/community indexes not given, but high biodiversity gains confirmed through vegetation surveys.

Biophysical impacts: Others

Ecosystem impact climate regulation
No specific impact
Increased evapotranspiration information
Likely increased due to more vegetation cover and soil wetness, but no quantified value.
Other biophysical impacts
Enhanced microclimate regulation and re-establishment of natural successional processes in riparian zones.
Lessons Learned
Key lessons
Main lessons taken from this site (and the project as a whole included):
- Pre-implementation monitoring was crucial to determine appropriate actions, such as installing over 350 dams to restore hydrology.
- Public engagement ensured community understanding and support for the measures.
- Stakeholder attitudes and communication activities were significant success factors.
Drivers
Driver typeDriver roleComments
Organisation committed to itMain driverThe project took place as a result of Coillte's commitment to restoring priority habitats
Success factors
Success factor typeSuccess factor roleComments
Communication activitiesMain factorThese included signs, guided walks, and outreach for schools and visitors. They were key to local understanding.
Financing possibilitiesMain factorMade possible by access to LIFE Nature and matching national funds.
Attitude of relevant stakeholdersMain factorCoillte collaborated actively with government agencies and NGOs.
Attitude of decision makersMain factorProactive. The Forest Service supported the project and provided monitoring via the National Forest Inventory.
Existing institutional frameworkSecondary factorClear and functional partnership among Coillte, NPWS, Forest Service, and Woodlands of Ireland.
Cost effectiveness
Not quantified, but restoration goals were exceeded, suggesting high effectiveness.
Flexibility / Adaptability
The type and location of dam structures were adjusted based on site-specific data (hydrology, topography, vegetation). Flexibility was also shown in species selection, favouring alder, willow, ash, or birch depending on micro-site water conditions.
Transferability
The project is highly transferable to other sites with degraded alluvial forests due to drainage or forestry intensification, hydromorphic or organic soils, possible hydrological connectivity with nearby rivers or floodplains.

Factors that complicate transfer : Dependence on EU funding (e.g. LIFE), not always available elsewhere. Land use change (e.g. abandoning intensive forestry) may be harder to justify or negotiate on private lands than public land ownership here with Coillte.
Basin characteristics influence
Local hydrology and former drainage systems significantly affect water retention outcomes.
Sources