Case study:Biodiversity conservation and recovery in the river basin Asón

Jump to: navigation, search
(0 votes)

To discuss or comment on this case study, please use the discussion page.

Location: 43° 21' 10", -3° 26' 0"
Edit location
Loading map...
Left click to look around in the map, and use the wheel of your mouse to zoom in and out.

Project overview

Edit project overview
Status Complete
Project web site
Country Spain
Main contact forename Carlos
Main contact surname Sánchez Martínez
Main contact user ID
Contact organisation Fundación Naturaleza y Hombre
Contact organisation web site
Partner organisations
Parent multi-site project
This is a parent project
encompassing the following
Project picture

Project summary

Edit project overview to modify the project summary.

The Asón River source is located in the Collados del Asón Natural Park. It flows through habitats classified as of Community Interest. These are the habitats of species of great interest such as Pyrenean musk rat, wolf, salmon and European bison. Downstream, where the waters from the river meet the sea, are the Santoña salt marshes. This site is an important staging post on the migration route for hundreds of species of birds, which congregate there during the winter. Three sites representative of the valuable ecosystems along this river have been proposed for inclusion in the Natura 2000 network.

The aims of the project comprise not only the hydromorphological restoration of the river, but the conservation of the entire river basin. The project carries out diverse actions in three areas of the basin: at the head, in the middle, and at the estuary. The measures at the river include environmental education information and awareness at the interpretation centre of the SCI. The improvement of instream habitat for salmonids, the recovery of otter, silvicultural treatments and hydrological study are some of the actions developed.

This project counts with the support of local, regional, national and European institutions. The financing comes from the LIFE initiative, the Consejería of Agriculture and Fisheries, Ministry of Environment, INEM and Caja Cantabria.The total budget was of 1,233,905.50 €. The UE cofinanced part of the project with 616,952.75 € from the Life initiative. Environment, INEM and Caja Cantabria.

Monitoring surveys and results

Edit project overview to modify the Monitoring survey and results.

Technical studies were completed, authorisations obtained and management plans were prepared for the three sites.

A total of 25 Cantabrian chamois (Rupicapra pyrenaica parva) were reintroduced and seven young were born, bringing the total to 32 animals present at the end of the project. Some 62 ha of land was bought (34 plots) and reforested with beech (Fagus silvatica) forest, and agreements were signed for the reforestation on an additional 23 ha. An agreement to lease 30 ha of holm oak forest was obtained. Agreements with hunting associations to lease hunting rights and create no-hunting zones were signed for 4 226 ha within the SCIs. Forestry management included planting of trees, protecting trees with photodegradable guards, creating fire breaks, and scrub clearance. As a result of this project work, monitoring showed that numbers of the following species had increased: wolf, European hare (Lepus europaeus), Roe deer (Capreolus capreolus), common wood pigeon (Columba palumbus) and Golden eagle (Aguila chrysaetos). Fencing was erected at the entrance to a cave, which was being used for sheltering livestock, to reduce disturbance to several colonies of two Habitats Directive Annex II bat species (Rinolophus ferrumequinum and R. hipposideros). Since its installation, the colonies have increase from 12 to 22. Three dams were to be removed on the Asón river – but this was revised to the building of fish passes instead. These were not established in the project duration although the necessary permissions were obtained. After an environmental impact assessment and hydrological studies, 12.5 ha of the Montehano salt marsh was re-flooded and 13 ha of exotic species, such as Eucalyptus, were removed. Surveillance patrols managed fire risk and hunting, as well and ecological monitoring. An interpretive centre was set up and outreach included school children, farmers, fishermen, hunters, tourists and cavers. In addition to the land the project purchased, a further 63 ha were ceded by councils and associations for restoration and conservation.

At the end of the project, the Foundation obtained an Interreg IIIB [Interreg is an EU-funded programme, IIIB deals with transnational co-operation involving national, regional and local authorities] project (“Waterwaysnet”) to allow the awareness-raising and habitat investigation actions to continue.

The broad awareness-raising campaign has reached women’s associations, schoolchildren (12 schools, 1 500 students in 2000-2001), the general public, farming and fishing unions, sports associations(cavers), tourism-related institutions. In all, some 35 institutions have been informed about the project.

Lessons learnt

Edit project overview to modify the lessons learnt.

One of the main pressures is the surface water abstraction. In 1973 the Hydraulic Planning Service had the rights for extract 150 l/s over a period of 99 years from the Confederación Hidrográfica del Norte. The demographic evolution of the coast towns (even higher during the summer), the urbanisation and the increase of the industrial use of water made this concession obsolete. Subsequentley, the construction of bombs and the substitution of the existing pipes by ones of bigger capacity enabled the extraction of an amount of water much higher than allowed.

The reduction of flow at dry summer periods is reflected in the inexistence of flow. Also,this decrease would affect not only the Asón River, but to the Marshes themselves, where changes in the patterns of salinity (keys to the very existence of the marsh)during periods of severe drought alterations, may affect the biological communities.

Other threats to this site derived from human activities and over-use of the resources are: draining of the marshes, unauthorised shellfish farming, illegal fishing, poaching and the spread of exotic species. Misplanning and mismanagement of tourism, in turn, are having an adverse impact on conservation of some of these sites.

Image gallery

Birth of Asón River in Cailagua waterfall
Aerial view of Asón River in Ampuero
Ason River un Ramales
Ason River in a reach without modifications
Ason River in a channeled reach

Catchment and subcatchment


River basin district
River basin Asón


River name Asón
Area category 100 - 1000 km²
Area (km2)
Maximum altitude category 200 - 500 m
Maximum altitude (m)
Dominant geology Calcareous
Ecoregion Ibero-Macaronesian
Dominant land cover Extensive agriculture
Waterbody ID


WFD water body codes
WFD (national) typology
WFD water body name
Pre-project morphology Sinuous
Reference morphology Sinuous
Desired post project morphology
Heavily modified water body true
National/international site designation
Local/regional site designations Natura 2000
Protected species present
Invasive species present
Species of interest
Dominant hydrology Artificially regulated, Estuary
Dominant substrate Estuarine mud
River corridor land use Intensive agriculture
Average bankfull channel width category
Average bankfull channel width (m)
Average bankfull channel depth category
Average bankfull channel depth (m)
Mean discharge category
Mean annual discharge (m3/s)
Average channel gradient category
Average channel gradient
Average unit stream power (W/m2)

Project background

Reach length directly affected (m) 39000 m
39 km
3,900,000 cm
Project started 1999/05/01
Works started
Works completed 2004/11/01
Project completed
Total cost category
Total cost (k€) 1233 k€
1,233,000 €
Benefit to cost ratio
Funding sources Consejería of Agriculture and Fisheries, Ministry of Environment, INEM and Caja Cantabria, EU LIFE Programme

Cost for project phases

Phase cost category cost exact (k€) Lead organisation Contact forename Contact surname
Investigation and design
Stakeholder engagement and communication
Works and works supervision Fundación Naturaleza y Hombre Carlos Sánchez Martínez
Post-project management and maintenance

Reasons for river restoration

Mitigation of a pressure Riparian development, Discharge licence
Hydromorphology Quantity & dynamics of flow
Other reasons for the project Conservation of the entire Asón basin


Structural measures
Bank/bed modifications Weir removal
Floodplain / River corridor Removal of exotic plants
Planform / Channel pattern
Non-structural measures
Management interventions Management for increase species like Lepus europaeus, Capreolus capreolus, Columba palumbus andAguila chrysaetos
Social measures (incl. engagement) Surveillance patrols managed fire risk and hunting
Other Interpretive centre was set up


Hydromorphological quality elements

Element When monitored Type of monitoring Control site used Result
Before measures After measures Qualitative Quantitative
Quantity & dynamics of flow Yes Yes Yes Improvement

Biological quality elements

Element When monitored Type of monitoring Control site used Result
Before measures After measures Qualitative Quantitative

Physico-chemical quality elements

Element When monitored Type of monitoring Control site used Result
Before measures After measures Qualitative Quantitative

Any other monitoring, e.g. social, economic

Element When monitored Type of monitoring Control site used Result
Before measures After measures Qualitative Quantitative

Monitoring documents

Additional documents and videos

Additional links and references

Link Description ref=LIFE99%20NAT/E/006333&area=1&yr= Life Project Link

Supplementary Information

Edit Supplementary Information