OPTAIN : Petite Glâne River Basin [Switzerland]

Summary

Summary

The case study area “Petite Glâne” belongs to the Broye catchment in the southwestern part of the Swiss Plateau. The river Petite Glâne is about 30 km long, repeatedly crosses borders between the cantons of Vaud and Fribourg, and has a catchment area of 94 km2. Its upper reaches have remained fairly natural and are lined with forest, whereas its lower reaches in the Broye plain have been canalized and straightened. The soils and climate here are highly suitable for arable farming. Overall, the catchment of the Petite Glâne is strongly characterized by agriculture: nearly three quarters of its area consists of pastures and cropland. However, the region is increasingly experiencing water shortages in summer, and there is often not enough water in the Broye and Petite Glâne to irrigate the fields. Climate change will further aggravate the situation. Farmers are therefore considering new options to mitigate the increasing drought events – for example an irrigation project using water from Lake Neuchâtel.Against this background, OPTAIN explores efficient land use and land management strategies as well as technical measures that increase the capacity of soils to absorb and store water while improving nutrient retention and decomposition. These natural and small water retention measures (NSWRMs) are discussed and evaluated jointly with regional stakeholders.

Based on model calculations, OPTAIN works to determine the maximum possible water and nutrient retention potential that can be achieved with NSWRMs if they are optimally combined and positioned in the catchment. Although the focus is on the Petite Glâne, the case study extends to the entire Broye catchment when it comes to modelling and stakeholder involvement.

The OPTAIN project supported 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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Overview
Year of issue
2025
Project
OPTAIN
Implementation status
Modeled
Location of the project
Swiss Plateau
Country
Switzerland
NUTS2 Code
Espace Mittelland
Sponge measures implemented in the case study
Minimum tillage
Strip cropping along contours
Intercropping
Buffer strips and hedges
Involved partners
Authority typeAuthority nameAuthority roleComments
Research institute / UniversityCentre for Development and EnvironmentDetermination of design details of the measureIn coordination with the following stakeholders: Authorities of the agricultural sector, authorities of the environment sector, famer associations, local farmers, NGOS, and AGRIDEA
Site Information
Climate Zone
Cool temperate moist
Precipitation
1100.00 mm
Temperature (°C)
9.00 °C
Evapotranspiration
650.00 mm
Runoff
350.00 mm
Elevation range
Petite Glâne: 429 – 820 m.a.s.l. Broye: 429 – 1513 m.a.s.l.
Slope range
moderate (6 - 10%)
Soil type
Cambisols
Luvisols
Vegetation class
The predominant vegetation in the catchment area comprises grass turf and dryland grasses.
WFD Ecological status
Moderate
WFD Chemical status
Unknown
Water quality status
Moderate: Some deviation from natural conditions, but functional.
Design and Implementation
Project scale
Micro
Project scale specifications
Micro and Meso-scale
Project area
Petite Glâne: 94 km2 Broye: 602 km2
Project area specifications
Agriculture, pasture
Financing
Total cost
1263155.13 €
Policy and Governance
Land ownership
Most land is owend by local farmers
Policy targets
Improved Biodiversity
Part of a wider plan
Yes
Public consultation
No
Consultation activities
Activity stageActivity typeKey issues
Screening phaseMARG workshopThe project involves a Multi-Actor Reference Group (MARG) composed of farmers, local and regional authorities, NGOs, and researchers to co-develop realistic solutions tailored to regional challenges.  Engagement with local communities and stakeholders.
Has contractual arrangements
No
Impacts and Monitoring

Maintenance

Maintenance requirements
Reforestation and afforestation projects along the river Water quantity (permanent) and quality (single samples). Drought Resistnat Crops: Maintenant Costs (for 0.22ha: CHF 1450.- per year)
Lessons Learned

No information provided for this section.

Sources

No information provided for this section.