OPTAIN : Wimbe River Basin [Belgium]

Year of issue
2025
Summary

The Wimbe basin is about 112 km2 in size and is classified as a continental bioregion. The basin consists of the water bodies LE8-10. The municipalities within the basin are Daverdisse, Wellin, Beauraing, Gedinne and Rochefort. The basin’s land use is 2% urban, 21% arable, 11% pasture and 66% forest. The region where the stream flows is representative of the Famenne schisteuse and the landscape is open. The region is vulnerable to both floods and low flows. The area is also vulnerable to nitrate concentration in water that is exceeding or is likely to exceed 50 mg/l, may have undergone or likely to undergo eutrophication.

The OPTAIN project will support the case study team with identifying and developing efficient land management strategies and small technical solutions to improve the soils’ infiltration and water holding capacities as well as its capacity to filter, buffer and transform pollutants.

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Location
50.067272, 5.226663
Project
OPTAIN
National ID
BE_05
Sector
Agriculture
Contact
Ghent University

Overview

Country
Belgium
NUTS2 Code
Prov. Namur
Sponge measures implemented in the case study
Buffer strips and hedges
Wetland restoration and management
Maintenance of forest cover in headwater areas
Forest riparian buffers
Involved partners
Authority type Authority name Authority role Comments
NGO Natagriwal Determination of design details of the measure They advise farmers, land owners related to implementing the measures, also support related to the administrations, regarding the design, yes to some extent they do this. They are “A non-profit association or ASBL
NGO Natagora Implementation They implement the measures to some extent, or help in implementing the measure. They also maintain the measures that they implement.
NGO CRLesse Implementation They implement measures via the funding given to them by the government. They are “A non-profit association or ASBL. Their role is to bring together all water users with the aim of maintaining or restoring good ecological status of the water, through concerted management, each within the framework of their responsibilities."

Site Information

Precipitation
844.00 mm
Temperature (°C)
9.80 °C
Evapotranspiration
405.00 mm
Runoff
331.00 mm
Elevation range
250-299 m.a.s.l.
Slope range
Whole catchment: Max=18.6%, Mean=9.9%, Min=0.01%, stddev=9.2%
Soil type
Cambisols
Groundwater level
35m (deepest)
Vegetation class
The agricultural area (~35%) is mainly cultivated with grasses. Maize and grains are also cultivated aside from the grasses.
WFD Ecological status
Good
WFD Chemical status
Failing to achieve good

Financing

Financing authorities
Authority name Type of funding Comments
CAP Pillar 2 EU-funds: Rural development funds EU funds
Wallonie government Sub-national funds regional funds

Policy and Governance

Policy description
The Wimbe basin is vulnerable to both flooding and low flow events. Agricultural activity within the watershed has impacted the quality of the water, particularly through erosion. The area is also vulnerable to groundwater nitrate pollution, with concentrations that can potentially exceed 50mg/L in certain areas.

The project will be implemented in coordination with the following stakeholders: Contrat de rivière Lesse; Parc Naturel de l’Ardenne Méridoniale; Natagriwal; Natagora; Fédération Belge du Secteur de l’eau Belgaqua; Public Service of Wallonia (SPW) Agriculture, Natural resources, Environment; Fédération Wallonne de l’Agriculture; Province Namur Cellule Cours d’Eau, Commune de Daverdisse, and local farmers.
Land ownership
around 70% of agricultural land are rented
Policy targets
Erosion Control
Pollutants Removal
Peak-flow reduction
Requirement directive
Requirement directive
Common Agriculture Policy
Nitrate Directive (NiD) 91/676/EEC
European Natura 2000 Network
Part of a wider plan
Yes
Wider plan
Wider plan type
Regional
Public consultation
No
Has contractual arrangements
No

Impacts and Monitoring

Monitoring System

Presence of formal monitoring system
yes

Lessons Learned

Barriers
Barrier type Barrier role Comments
Other Main barrier loss of land, economic loss
Other — administrative burden
Drivers
Driver type Driver role Comments
Other Main driver landowners, land users
Organisation committed to it Main driver Policy makers and advice of experts to policymakers
Success factors
Success factor type Success factor role Comments
Available support tools Main factor Incentives
Existing staff and consultant knowledge Main factor Assistance from non profit organizasation
Existing regulations Main factor Legislation