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Reconstruction of the hedgerow on the Léguer basin

Last update
2025
Summary
The Léguer River catchment is one of the most hedged areas in Brittany, but has suffered a decline in its hedgerow mesh as a result of agricultural mechanization and land consolidation operations. Faced with the degradation of the Leguer's water quality observed in the 1990s, elected officials in the watershed became aware of the need to preserve the hedgerow, and to consider its restoration to improve water quality. Since 1999, the Leguer's watershed committee undertook awareness-raising of the watershed population, before experimenting with the restoration of hedges and embankments in several pilot basins.

This work was then extended to the entire watershed, leading to the restoration of hundreds of kilometers of hedges and embankments. This action is still ongoing today (with new hedges planted every winter), however no longer managed at the whole basin scale but by different intermunicipalities.

It aims in particular to ensure the sustainability of existing linear thanks to urban planning tools and the promotion of hedged farmland.

A complementary action comes with the river management (as the Léguer is labellized "Wild River"), which includes riparian forest restoration to create shade on the river and reduction of the risk of water heating, purification processes, biodiversity of the watercourse, etc.

The developpment of agroforestry and intercropping is also being studied to further the agricultural practices evolution in the basin.
Position
Latitude
48.5865
Longitude
-3.3920
Project
NWRM
National Id
France_15
Installation date
1999-ongoing
Implementation Status
RBD code
FRG-La Loire, les cours d'eau côtiers vendéens et bretons
Transboundary
0

Location of the project
The Leguer is a coastal river of the Côtes d'Armor that flows into the Bay of Lannion, and whose basin has a historically dense hedgerow mesh.
NUTS Code
FR52 - Bretagne
Project's objectives
The main objective of the project was to improve water quality and control erosion. Limiting runoff allows water to stay longer before reaching the watercourses, giving time to natural processes to occur to purify the water by soil microorganisms or light.
Secondly, the restoration of hedged land is of interest for biomass supply, biodiversity conservation, carbon sequestration, renewable wood production, for the wind-breaking role of hedges, livestock protection and landscape restoration.

There has been some quantified objectives (eg. linear length of hedges planted) but not for the whole project.
Involved Partners
Authority type Authority name Role Comments
Local water authority
Lannion Trégor Communauté (LTC)
Implementation
A mutli-municipality administration, common organisation in France to gather resources to manage technical topics such as water, waste and other topics.
Local water authority
Comité bassin versant du Léguer (CBVL)
Initiation of the measure
Former authority on this project.
Architects/Engineers
Implementation
Various civil engineering and forestry companies
Local water authority
Guingamp Paimpol Agglomération (GPA)
Implementation
A mutli-municipality administration, common organisation in France to gather resources to manage technical topics such as water, waste and other topics.

Climate zone
cool temperate moist
Temperature
11.4 °C
Annual rainfall range
900 - 1200 mm
Elevation range
167 m
Vegetation class
This is a highly hedged landscape ("bocage"), with approximately 150 linear meters of hedges per hectare.
Water bodies: Ecological Status
Good
Water bodies: Chemical Status
Failing to achieve good
Water quality status
Eutrophication issues due to agricultural activity.

Project scale
Large
Project scale specification
The project is covering the entire Léguer river basin and specific research were conducted on sub-catchments.

It also initiated a 'Hedgerow' label, certifying the proper management of hedgerows within a territory, with a national recognition.
Performance timescale
< 1 year
Project area
50 000 ha
Area specifications
More than 300 km of planted or restored hedges and embankement, actively growing every year.
Lifespan
Long-term/permanent, assuming sustainable maintenance keeps going.
A voluntary collaboration with farmers. Co-developing a hedgerow management plan with them.
The landscape is historically hedged. There is a cultural commitment among farmers, and we know that hedges will be effective.
The planting of hedges helps to fight against erosion and improve the quality of surface water. The many co-benefits of this measure have contributed to the progressive extension of the restoration program to the entire watershed.

Total cost
Millions of euros
Costs total information
Total hard to stimate as it depends every year and spans accross different institutions.

Local fundings provided by water providing authorities and complemented by external sources (European, national, regional).
Financing authorities
Authority name
European Union
Type of funding
EU-funds: Rural development funds
Financing share
70%
Comments
Contributes to the external subventions of about 70% (varying % each year)
Authority name
Conseil général des côtes d’Armor (Department)
Type of funding
Sub-national funds
Financing share
70%
Comments
Contributes to the external subventions of about 70% (varying % each year)
Authority name
Loire-Bretagne Water Agency
Financing share
70%
Comments
Contributes to the external subventions of about 70% (varying % each year)
Authority name
Bassin Versant Vallée du Léguer (BVVL)
Type of funding
Local funds
Financing share
30 %
Comments
Former local catchment water authority that implemented the measures
Authority name
Intermunicipalities (EPCI Lannion Trégor Communaté (LTC) and Guigamp Paimpol Agglomération (GPA)).
Financing share
30 %
Comments
Currently carrying out the measures.
Compensations
0
Compensations annual information
There was no need for compensations as there were no actual loss for the occupied surfaces, which remain under CAP fundings.

Policy context
The Léguer River catchment area is one of the most hedgerow territory in Brittany, with an average 150 meters of hedge per hectare. However, this hedgerow has been gradually eroded as a result of agricultural mechanization and land consolidation, as well as the phasing out of hedge and slope maintenance seen as a cost without any benefit. This decline was estimated at a loss of 3 linear meters per hectare per year.

In Brittany, 80% of drinking water comes from surface water pumping, which makes this resource fragile and sensitive to diffuse or point pollution. Several water intake points were closed in the mid-1990s due to significant water quality degradation. Due to the positive influence that hedgerow can have on the quality of surface water, policies for the preservation and restoration of hedgerow have emerged in the region.
Land ownership
Mostly private farmland (farmers/landowners); plus public roadside hedges managed by communes.
Community involvment
No
Design consultation activity
Activity stage Name Key issues Comments
Policy target
Target purpose
Runoff control
Peak-flow reduction
Pollutants Removal
Oher Societal Benefits
Erosion Control
Target Remarks
Improve water quality and curb erosion; restore hedges/embankments basin-wide (~300 km restored since 1999).
Policy pressure
Pressure directive Relevant pressure
Pressures remarks
Water quality issues and the loss of cultural history of the landscape were the main pressures that motivated the project.
Policy impact
Impact directive Relevant impact
Requirement directive
Requirement directive Specification
Contractual arrangements
1
Arrangement type Responsibility Role Name Comments
Contractual agreement
Agreement between the land owning farmer and the implementing authority.
The implementation authority takes care of the maintenance the first 3 years after plantation of a hedgegrow in the farmer's land.
The farmer continues after that. He is the owner of the biomass produced (wood).
The maintenance of the hedgrowth follows an official Sustainable Hedgegrowth Management Plan (Plan de Gestion Durable des Haies or PGDH), which is concieved for the farmer by the public authority for free.
Part of wider plan
1
Wider plan type
Wider plan type Wider plan focus Name Comments
Regional
Environment & Biodiversity
"Breizh bocage"
The programme aims at the Brittany region level to enhance protection and restoration of hedgerow landscapes.

The project does not implement monitoring of the flow and water level of the Leguer.
Only short studies, limited in time and space were carried out/

Betwenn 2000 and 2002, the Comité du Bassin Versant du Léguer (CBVL) conducted a study of the Kervulu watershed (pilot basin) to assess the effect of hedgerow restoration and changes in practices on water quality.

The Leguer hedgerow project, led by INRA (UMR BAGAP), aimed to evaluate the role of the hedge as a shelter for auxiliary fauna, both through the in situ assessment of hedge biodiversity at the hedge and farm levels, and through the analysis of the ecological connectivity of the landscape and the establishment of ecological networks in planning documents.
Maintenance
Clearing out seedlings so that smaller ones can grow without being buried. Pruning growing trees to match desired growth.
Catchment outlet
A pre-configuration study was conducted to assess the effect of hedgerow restoration and practice changes on water quality.
No cost assessement was studied, no other measures were considered.
An economic benefit comes from the sale of wood, purchase and drying to sell in wood chips to equipped communities.

Energy-wood production in the basin was estimated in 2019 as € 980,000 yearly, 39 % of which is from the bocage part.
Carbon storage in the bocage elements of the Léguer basin as an ecosystemic service was estimated in 2018 as € 54 millions + € 1.2 million for annual additional captation.
Hydrological effects
The hydrological response to rain event seems longer than river basins with no action on hedgerows. Farmers also report complete stop of mud flows in lower areas of the fileds which were previously common problem.
Information on runoff reduction
Runoff is slowed down by the bocage landscape.
Maintenance baseflow
1
Information on Maintenance baseflow
The slowed down water runoffs maintains higher water quantity in the Léguer Basin.
Information on Reducing flood risks, quantity
During floods, it was observed that the hydrological behaviour of the Leguer appeared less reactive than that of other nearby rivers that had not been the subject of such a restoration program.
In addition, farmers report that they have noticed the disappearance of mud flows on the lower part of their fields following the creation of hedges that break the slope.
Water quality overall improvements
Positive impact-WQ improvement
Information on Water quality overall improvements
The study carried out in the Kervulu basin showed that the sub-basins that had been the subject of restoration of the hedgerow coupled with the adoption of rationale weed control practices contributed less to pollution (in particular phosphorus and pesticides) of surface water than the other basins.

Overall, a reduction of chemical and nutrient pollution has been found.
Information on Water quality Improvements (N)
Since the 2000s, an improvement has been observed on the nitrate parameter, while it was increasing in the 1990s.
Information on Water quality Improvements (W T°)
Water heat is limited with the shading provided.
1
Monitoring (Léguer Bocage Project) has demonstrated the role of hedgerows as refuge habitats for biodiversity. Urbanistic plans include the hedgegrowths as ecological corridors (Trame Verte & Bleue).
Information on Ecosystem impact GHG soil carbon
Hedgegrowth annual captation : 19,982.99 tons eq.CO₂
Hedgegrowth annual stock : 713,829.98 tons eq.CO₂

Key lessons
The area was primarily the subject of consolidation actions to increase size of fields by agriculture authorities. This led to an important destruction of hedgerows and some farmers were therefore reluctant to replant hedges shortly after.

The fact a wood energy sector using wooden chips elaborated using recovered wood from the maintenance of hedges has helped convince local stakeholders to engage at such a large scale. About 100 farmers out of 600 in the basin are volonteers in this project.

More than 300km of hedgerows and embankments have been restored in the basin, with around 20km more every year. The hedges reconstitutions are slowing down each year, but the volontary farmers are more motivated than ever.

A reduction of pollution has been found. The habitat role of hedgerows for agriculture auxilaries, made possible in oparticular with a diverse and good stratified hedge

The project has created a common dynamic towards preservation and restoration of hedges and embankment beyond farmers, including citizen and elected officials and created a territorial identity.

The project leader underline is important to watch not only the increase of the hedgerows but also their maintenance.
Success factor(s)
Success factor type Success factor role Comments Order
Attitude of relevant stakeholders
main factor

High motivation of some farmers to participate in this project.

Their sensitivity to biodiversity preservation and/or to bocage culture valorization.

1
Financing possibilities
main factor

Access to various funds allowed this expensive measure to continue.

2
Barrier
Barrier type Barrier role Comments Order
Attitude of relevant stakeholders
secondary barrier
Some farmers are reluctant to plant hedgerow lines soon after participating in land consolidation actions.
1
Attitude of relevant stakeholders
secondary barrier
The increasing legal protection status of hedgegrowth causes increasing reluctance for farmers to create hedges on their land.
2
Other
secondary barrier
Climate change provide more droughts events, which causes higher costs and difficulty to create hedges (young plants mortality).
3
Other
secondary barrier
"Bocage" agricultural landscapes suits better livestock activities than cereal production. But the economic context is in favor of cereal planting.
4
Driver
Driver type Driver role Comments Order
Transferability
Hedgerows are transferable to other agricultural landscapes, even those with few hedgerows, which offer a great opportunity to quickly create long linear lengthes of hedges.
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