Órbigo River ecological status improvement, Spain

Summary

Summary

Órbigo River (Duero Basin, NW Spain) ecological status improvement. A bundle of sponge measures - levee removal/set-back, rip-rap removal, recovery of secondary channels, floodplain reconnection, natural bank stabilisation, and riparian buffer restoration - was implemented under the WFD and Floods Directive; the project was a 2013 IRF European Riverprize finalist.

Section I (upper ~23.5 km) was built in 2011–2013: ≈4.72 km of rip-rap and 8.71 km of levees were removed, 3.13 km set back, ~10 km of side channels reopened, and ~300 ha of floodplain reconnected; limited works followed in Sections II–III. The Alcoba weir was modified by cutting a central notch (~15–16 m) with seasonal removable boards and a ramp to restore fish passage and sediment/nutrient continuity, reconnecting ~25 km of river.

Post-project assessments report increased channel dynamism and sinuosity and riparian vegetation regeneration - moderate effectiveness in the short term, underscoring the need for long-term monitoring. Overall, actions improved lateral and longitudinal connectivity and enhanced natural flood attenuation; AdapteCCa summarises ~480 ha of floodplain now functioning with the river.

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Overview
Year of issue
2025
Project
NWRM
Implementation status
Completed
Contact
Gonzalo Delacámara and Marta Rodrí­guez (IMDEA Water) in close cooperation with Ignacio Rodríguez Muñoz, José Ignacio Santillán Ibáñez and Rosa Huertas (Duero River Basin Authority, Confederación Hidrográfica del Duero)
Location of the project
This application has been implemented in a 23.5 km long stretch (stretch I) of the Órbigo River (Duero River Basin) located in the northwest of Spain.
Country
Spain
NUTS2 Code
Castilla y León
Sponge measures implemented in the case study
Floodplain restoration and management
Forest riparian buffers
Removal of dams and other longitudinal barriers
Natural bank stabilisation
Elimination of Grey River Bank Protection
Stream bed re-naturalisation
Objectives
Project-wide aims (108 km): restore lateral connectivity (remove/set back levees/riprap, reopen floodplain/secondary channels), improve longitudinal connectivity (permeabilize weirs, notably Alcoba), and restore riparian buffers and dynamics, integrating WFD and Floods Directive goals.
Involved partners
Authority typeAuthority nameAuthority roleCommentsAuthority responsibility
National water authorityMinistry of Environment and Rural and Marine Affairs (Ministerio de Medio Ambiente, Medio Rural y Marino), MARMInitiation of the measureProviding a general framework (drawing up the National Strategy on River Restoration, ENRR) in which this initiative can take place)Responsible
Regional / sub-national water authorityRiver Basin Authority (Confederación Hidrográfica del Duero)Determination of design details of the measureSelecting a candidate project to be developed within the framework of the National Strategy on River Restoration. Selection criteria based on IMPRESS, Methodological Guide on River Restoration and priority areas aimed at improving connectivityResponsible
Regional / sub-national water authorityRiver Basin Authority (Confederación Hidrográfica del Duero)ImplementationPreparatory, diagnosis, public hearing process and worksResponsible
National water authorityMinistry of Environment and Rural and Marine Affairs (Ministerio de Medio Ambiente, Medio Rural y Marino), MARMImplementationParticipation during preparatory, diagnosis, public hearing process and worksResponsible
OtherMunicipalities (Ayuntamientos): Cimanes del Tejar, Llamas de la Ribera, Carrizo de la Ribera, Turcia and Santa Marí­a del ReyImplementationParticipation during preparatory, diagnosis and public hearing processSupporting
OtherLocal entity (Juntas vecinales)ImplementationParticipation during preparatory, diagnosis and public hearing processSupporting
NGONeighbourhood associationsImplementationParticipation during preparatory, diagnosis and public hearing processSupporting
National water authorityMinistry of Environment and Rural and Marine Affairs (Ministerio de Medio Ambiente, Medio Rural y Marino), MARMFinancingWithin the framework of the National Strategy on River RestorationSupporting
Regional / sub-national water authorityRiver Basin Authority (Confederación Hidrográfica del Duero)Monitoring—Supporting
Site Information
Climate Zone
Warm temperate dry
Precipitation
535.00 mm
Temperature (°C)
10.70 °C
Elevation range
900 m
Slope range
0-1% (average slope of the Órbigo River Stretch I: 0.3%)
Vegetation class
Riparian vegetation with poorly preserved continuity due to replacement with other uses (adjacent crops: agro (irrigation) and forest (poplar: Populus x euroamericana).
WFD Ecological status
Good
WFD Chemical status
Good
Water quality status
All good : Oxygen: 9.79 mg/l, pH: 7.71, Ammonium: 0.05 mg/l, BOD5: 2.00 mg/l, Nitrate: 1.12 mg/l, Diatom index: EQR IPS 2007: 1.17 , Macroinvertebrates EQR IBMWP: 1.53.
Design and Implementation
Project scale
Meso
Project scale specifications
Length of the stretch to be improved by means of this specific project: 23.5 km. Area: around 45 ha.
In the near future (already passed environmental and technical assessment and pending to obtain funding) similar projects will be carried out in downstream stretches (segment II: 27.5 km; and segment III: 57.8 km)
Project area
160500
Area subject to Land use change or Management/Practice change (ha)
45.00 ha
Size
45.00
Size unit
ha
Financing
Total cost
3084697.25 €
Total cost information
This is the total projected budget. Budget breakdown: 1. Lateral connectivity and dynamics improvement works (52.01%); 2. Longitudinal continuity improvement works (15.70%); 3. Riverbank estabilization works (7.52%); 4. Site access improvement (11.14%); 4. Supplementary works (2.57%); 5. Other items: monitoring of works (3.89%); environmental monitoring (3.89%); risk prevention (2.23%); waste management (1.06%)
Executed budget: 2065264.81 €
Costs land acquisition information
Null value as intervention were carried out in Public domain land
Costs operational information
Commonly no operational cost is associated to this kind of project (river restoration) [Source: Garcí­a et al. (2013)]
Costs maintenance information
Variable according to the specific element considered (average values for Spanish river basins: 1.2% of initial investment cost for fishladders; 20% of total investment cost for revegetation works; 15% of total investment cost for bioengineering works). Due to the implementation of the project maintenance costs have been drastically reduced. These costs were expected to be very low and assumed by the Duero River Basin Authority within the framework of its Public Domain Conservation Programme
Financing authorities
Authority nameType of fundingCommentsFinancing share
Ministry of Environment and Rural and Marine Affairs (Ministerio de Medio Ambiente, Medio Rural y Marino), MARMNational fundsThis measure is implemented within the framework of the National Strategy for River Restoration (ENRR, Estrategia Nacional de Restauración de Rí­os).100 %
Compensations
No
Policy and Governance
Policy description
The municipalities of Cimanes del Tejar, Llamas de la Ribera, Carrizo de la Ribera, Turcia and Santa Marina del Rey located by the Órbigo River (León province, Castilla y León Region) were suffering from the effects of hydromorphological (weirs, channels…) and land-use patterns change pressures for this water body: loss of lateral (main derived problem: floods) and transversal connectivity, river dynamics (derived problems: erosion and sedimentation) alteration, flow alteration and riparian forest loss and fragmentation.
Land ownership
Public land.
Policy targets
Peak-flow reduction
Runoff control
Erosion Control
Improved Biodiversity
Oher Societal Benefits
Target remarks
Flood control and flood risk mitigation. As a final aim. Recovering morphology and hydraulic capacity of the former stream bed of the river and its connectivity with the floodplain and improving longitudinal continuity (by means of works to 1) improve lateral connectivity and dynamics; 2) improve longitudinal continuity; 3) forest actions (revegetation)
Mass stabilisation and control of erosion rates.
Biodiversity and gene-pool conservation in riparia. More accurately: improve ecological status of the river.
Policy pressure
DirectiveRelevant pressure
Floods Directive identified pressureNatural Exceedence
Floods Directive identified pressureBlockage / Restriction
WFD identified pressure4.1.1. Physical alteration of channel/bed/riparian area/shore of water body for flood protection
WFD identified pressure4.2.2. Dams, barriers and locks for flood protection
Pressure remarks
Loss of lateral (main derived problem: floods) and transversal connectivity, river dynamics (erosion and sedimentation) alteration, flow alteration and riparian forest loss and fragmentation. Pressures for this water body (identified by IMPRESS): hydromorphological (weirs, channels...) and land-use patterns.
Policy impact
DirectiveRelevant impact
Floods Directive identified pressureWaterbody status (adverse permanent or long-term consequences ecological or chemical status of surface water bodies or chemical status of ground water bodies affected, as of concern under the WFD due to the hydromorphological impacts of flooding)
Floods Directive identified pressureInfrastructure (adverse consequences to infrastructural assets such as utilities, power generation, transport, storage and communication)
Floods Directive identified pressureOther environmental impacts: other potential permanent or long-term adverse environmental impacts, such as those on soil, biodiversity, flora and fauna, etc.
WFD identified pressureAltered habitats due to morphological changes
WFD identified pressureAltered habitats due to hydrological changes
Requirement directive
Requirement directiveSpecification
Floods Directive-mitigating Flood RiskBy means of measures aimed at giving river more space
WFD-achievement of good ecological statusBy means of measures aimed at improving the hydromorphological conditions of the water body (river continuity and morphological conditions, mainly)
Policy challenges requirements
National Strategy for River Restoration (Estrategia Nacional de Restauración de Río, ENRR), Sub-programme 3 (improvement of the longitudinal continuity of the rivers within the Duero basin) and 4 (improvement of the lateral continuity of the rivers within the Duero basin)
Part of a wider plan
Yes
Wider plan
Wider plan typeWider plan focusNameComments
NationalWaterNational Strategy for River Restoration (Estrategia Nacional de Restauración de Rí­o, ENRR)Sub-programme 3 (improvement of the longitudinal continuity of the rivers within the Duero basin) and 4 (improvement of the lateral continuity of the rivers within the Duero basin) [Source: Rodrí­guez et al., 2012a]
Public consultation
Yes
Consultation activities
Activity stageActivity typeKey issuesComments
Screening phase—Preparatory phase (year 2009): with municipal majors/neighbourhood associations'representatives. Using ortophotos (years 56-57, 2004 and 2008) as a basis for analysing changes in floodplain—
Design phase—a) Diagnosis phase (year 2009): Compilling and analysing information provided by the referred stakeholders; b) Informative sessions: with other interested stakeholders (inhabitants)—
Other—Public hearing phase (year 2009: alternatives were discussed and showed by means of computer simulation on the basis of ortophotos (years 2004 and 2008).[CHD, 2013b]: More than 50 meetings (in a period of 3 years) with stakeholders.
Other—Monitoring[Source: Barquero and Santillán (2012a)]
Design phase—Informative sessions (for stakeholder (inhabitants)—
Implementation phase—a) Informative sessions (for stakeholder (inhabitants); b) Dissemination activities (for external audience) and field trips: Riverbasin Authority/Ministry of Environnment Websites; Specialised national/international networks on river restoration (newsletters, presentations). 2013 IRF European Riverprize finalist practice.Field trips from: Universities, Administration bodies, within in the framework of specialised workshop; c) Newspapers; d) Volunteering and environmental education programme—
Screening phaseCONSULTATION ACTIVITIESPreparatory phase (year 2009): with municipal majors/neighbourhood associations'representatives. Using ortophotos (years 56-57, 2004 and 2008) as a basis for analysing changes in floodplain—
Design phaseCONSULTATION ACTIVITIESa) Diagnosis phase (year 2009): Compilling and analysing information provided by the referred stakeholders; b) Informative sessions: with other interested stakeholders (inhabitants)—
OtherCONSULTATION ACTIVITIESPublic hearing phase (year 2009: alternatives were discussed and showed by means of computer simulation on the basis of ortophotos (years 2004 and 2008).[CHD, 2013b]: More than 50 meetings (in a period of 3 years) with stakeholders.
OtherCONSULTATION ACTIVITIESMonitoring[Source: Barquero and Santillán (2012a)]
Design phaseCOMMUNICATIONInformative sessions (for stakeholder (inhabitants)—
Implementation phaseCOMMUNICATIONa) Informative sessions (for stakeholder (inhabitants); b) Dissemination activities (for external audience) and field trips: Riverbasin Authority/Ministry of Environnment Websites; Specialised national/international networks on river restoration (newsletters, presentations). 2013 IRF European Riverprize finalist practice.Field trips from: Universities, Administration bodies, within in the framework of specialised workshop; c) Newspapers; d) Volunteering and environmental education programme—
Has contractual arrangements
No
Impacts and Monitoring

Monitoring System

Monitoring requirements
This works are assumed by the Duero River Basin Authority
Monitoring parameters
So far: areas suffering from intense erosion and deposition processes; side arms dynamics according to variable water flow levels; wet areas after intense flood events (April 2013 and 2014) and perception of local population towards changes. Planned new activities to be carried out during 2014: topographic characterization of the most active areas.

Maintenance

Maintenance requirements
Channel : natural and dumped debris regular removal; removal of excessice or dead vegetation, sediment removal. Shoreline regular inspection and replacement of damaged vegetation when required. Fish ladders: inspection and structure repair/rehabilitation.

Impact Assessment Methodology

Performance impact assessment method
Catchment outlet
Performance impact estimation information
Field visits, drone images (comparison before and after floods), information from stakeholders.

Socio-economic Impacts

Direct benefits
Flood protection (material damage reduction)
Recognition as climate adaptation good practice

Biophysical impacts: Hydrology

Information on retained water
Variable volume of retained water according to circulating water flow and water depth. For this kind of intervention it is more appropriate to use the concept of "slow down flow water" and the use of simulation models (different water volumes and return periods). E.g. Flood lamination: 4-5 hm3; Water volume: 590 m3/s; Return period: 500 years
Information on peak flow reduction
According to the Planning Office (River Basin Authority) (on-going evaluation) NRWM have performed properly against floods that took place during Winter 2013 (160 m3 flood: same as those in 1995 and 2000 causing serious damage) and during the Winter of 2014 (300 m3). These were successfully abated thanks to NWRM [Source: River Basin Authority, personal communication]
Information on increased infiltration
Greater infiltration rate and rate of recharge of the natural floodplains.
Ecosystem flood control volume
160.00 m3
Information on ecosystem flood control volume
According to Planning Office (River Basin Authority) (on going evaluation) these NRWM have performed properly against floods that took place during Winter 2013: 160 m3 flood, (same that in 1995 and 2000 caused serious damage) was successfully abated thanks to implemented NWRMs
Information on Restoring hydraulic connection
Restored transversal and longitudinal connectivity, reopening ~10 km of side channels, and recovery of 300–480 ha of floodplain enhancing natural flood attenuation capacity. The Alcoba modification enables fish migration and sediment/nutrient continuity during non-irrigation seasons (boards removed), reconnecting ~25 km.

Biophysical impacts: Biodiversity

Improved biodiversity
Yes
Information on improved biodiversity
After dismantling levees and revetments along a ~21.6 km segment, the Órbigo showed channel widening and regeneration of riparian vegetation towards more natural willow/poplar communities, evidencing increased dynamism

Biophysical impacts: Water & Soil Quality

Water quality overall improvements
Not relevant for this application
Information on water quality overall
According to technical project, initial water quality status for the Stretch I (chemical/physical status /microinvertebrates/diatomes) was rated as good-very good so no specific measures were designed for this purpose. Despite of this, first evaluation results show that the ecological status of this water body has been improved.
Soil quality overall improvements
N/A info
Information on soil quality overall improvements
Positive effects regarding infiltration rate and rate of recharge of the alluvial natural floodplains and soil fertilization are expected but no empirical evidence has been obtained yet [Source: CHD (2013b]]
Information on soil quality, overall soil carbon
Positive impact-SQ improvement
Ecosystem erosion control
Yes

Biophysical impacts: Others

Ecosystem impact climate regulation
No information available
Lessons Learned
Key lessons
A 2013 IRF European Riverprize finalist.
a) Good practice of integrated water management and land use policies
b) Implementation of innovative concepts (e.g. “room for the river”, green infrastructure…)
c) Relevance of management and planning tasks.
d) Example of integrated approach in WFD and FD implementation
e) Example of the need to devote a great deal of time and effort to explain to the stakeholders the scope of the measures in order to achieve their acceptance and their participation. Multiplier effects are obtained when stakeholders became aware of the effectiveness of the measures.
e) Example of the relevance of public involvement during the whole process (public participation during the planning cycle and volunteering within the framework of environmental programme linked to the Project).
f) Impact on the media (beyond the pressnotes on the plan).
g) Replicability (downstream stretches) potential and networking potential (the project derived in the participation of the Basin Authority -together with other 4 European basin authorities- in the ECRR Community of Practice -launched in 2013 as a network for sharing their experiences in river restoration).
Barriers
Barrier typeBarrier roleComments
Attitude of relevant stakeholdersMain barrierAt first, local population was relunctant to the implementation of the project. Reasons: they didn't understand the theory (intervention was very different -aim was to create "room for the river"- to anything else carried out previously in the river) and how it would work in practical terms. [Source: CHD (2013a]]
Drivers
Driver typeDriver role
Past flooding eventsMain driver
Organisation committed to itMain driver
Success factors
Success factor typeSuccess factor roleComments
Public participationMain factorActive participation process during the whole life-cycle of the project
Attitude of decision makersMain factorInnovative approach, strong involvement and will to promote participation
Existing staff and consultant knowledgeMain factorInnovative approach, strong involvement and will to promote participation
Existing institutional frameworkMain factorCoordination between Ministry and River Basin Authority
Financing possibilitiesMain factor—
Cost effectiveness
Structural measures for flood protection traditionally applied in urban river stretches have resulted in very negative effects. Applied approach was assessed to a more cost-effective option than the traditional one.
Sources
Sources