Renaturation of the Seymaz river, Switzerland

General

National Id:

Switzerland_01

Site name:

Seymaz river

Summary:

The Seymaz renaturation project takes place in Switzerland, along the Seymaz river which is located in the eastern part of Geneva canton. The project consists in several renaturation measures: eliminating concrete casts, softing riverbanks and widening riverbed. A wetland (marshland) is also re-created. The project is part of the cantonal program which aims at improving ecological and countryside quality and reducing flood risk by managing peakflows. Two stakeholders groups have been involved in the project implementation: the Charte Seymaz group (“negociation” group on the renaturation program which include all concerned stakeholders) and the management group (Responsible for coordinating and managing the local arrangements). A main constraint of the project have been the nature of land use and property in the area concerned by the NWRM, since famers were mostly impacted by the project and first opposed to it.

The in-depth description of the case study:

cs-ch-01-final_version.pdf

NUTS Code:

Ticino

RBD code:

CH50

Transboundary:

Data provider:

Anaïs HANUS, ACTeon

Source(s):

La Seymaz

Les arrangements locaux et la durabilité de nouvelles activités rurales : le cas de la renaturation de la Haute-Seymaz (local arrangements and sustainability of new rural activities : the Haute-Seymaz renaturation case study)

Renaturation de la Seymaz

NWRM(s) implemented in the case study:

Stream bed re-naturalization

Removal of dams and other longitudinal barriers

Wetland restoration and management

Longitude:

6.180665

Latitude:

46.198248

Site information

Climate zone:

cool temperate moist

Mean rainfall:

971

Mean rainfall unit:

mm/year

Average temperature:

9,80000019073486

Average imperviousness:

0,0900000035762787

Type:

Case Study Info

Light or indepth?:

In-depth

Average slope range:

1-2%

Vegetation class:

Agricultural land use includes cereals, and some vineyards and vegetable crops. Artificial land is mostly for residential use.

Monitoring maintenance

Monitoring impacts effects:

Monitoring location:

In-Stream

Monitoring parameters:

Water flows are measured in different sites of Seymaz river (at least 3). Temperature and ecological status have been studies punctually. Water quality is monitored: - physic-chimical quality through parameters: nitrogen, phosphorous, metal, pesticides, organic carbon - ecological quality through two parameters: benthic macrofauna and diatomees

Performance

Performance impact estimation method:

Catchment outlet

Performance impact estimation information:

physic-chimical quality is measured every 6 years and ecological quality between every 1 to every 8 years

Biophysical impacts

Information on increased water storage:

800000m3

Water quality overall improvements:

Positive impact-WQ improvement

Information on Water quality overall improvements:

Water quality have improved after renaturation (from medium to good) but it still needs to be monitored.

Soil quality overall soil improvements:

N/A info

Lessons, risks, implications...

Key lessons:

The project has enabled land use regulation through social solidarity and economic efficiency, taking local interests into account in addition to global interests (regarding floods and biodiversity). This can have facilitated the acceptation and success of its implementation. Moreover, the measure happens to be more cost-efficient than previous projects of flood regulation.

Financing mechanism:

Financing mechanism information:

Compensation schema: farm owners and farmers have received financial compensation, either for selling their land or keeping it and managing it respecting a †œnature contract†. The payment was function of the number of concerned hectares. Moreover, punctual compensations have been done, for instance during works periods and for a loss of three year yields during when land was leveled. Farmers also beneficiated for tax advantages. The State also created a fund for regional agriculture promotion, beneficiating for land sales. The renaturation department transferred 1,9million CHF to this fund.

Financing difficulties:

Success factor(s):

Type	Role	Comments
Existing institutional framework	main factor	Main success factors have been: - the local political context, much more in favor of renaturation than other cantons (laws, fund...) - local arrangements such as the †œdrainage right† given t farmers - the high participation rate of farmers and other actors in the process decision and implementation (through Charte Seymaz group)
Specific incentives for stakeholder involvement	secondary factor
Financing possibilities	main factor
Public participation	main factor

Financing:

Type	Comments
Local funds	The main funding sources were: - the cantonal renaturation fund (45millions CHF) - the two laws on renaturation voted by Geneve State (27 million CHF) Incentives were used through compensations forward famers who sold their land or sign in a †œnature contract† regarding the way to manage it. Private funding has been made

Barrier:

Type	Role	Comments
Other	main barrier	Main implementation barriers have been: - the importance of property rights, mostly farmers ones, and the difficulty to deal with land property - the negotiation with farmers, highly impacted by the project and who were initially †œagainst† a total renaturation project. Their involvement in the decision process, the negotiation of compensations and decisions such as the non-expropriation of farmers or the †œdrainage right†, had to be discussed and taken into account. - previous conflicts that had occurred between farmers and nature organizations - non-expropriation has finally became a conflict factor
Attitude of relevant stakeholders	secondary barrier

Driver:

Type	Role	Comments
Past flooding events	main driver	Land use constraints have been the initiator factor to the implementation of the measure, since frequent floods happened to occur on farmlands in the Seymaz basin itself, linked to the artificialisation of the river during the past centuries. Floods in the urban areas downstream were already a problem. Political context, legislation and existing funding sources have been a main factor leading the choice for the implementation of the NWRM, instead of †œtraditional† works for flood management.
Organisation committed to it	secondary driver
Availability of subsidies	secondary driver

Financing share:

Share type	Share	Comments
National funds	100
Private funds

Socio-economic

Direct benefits information:

Benefits are: - Flood security and protection: reduction of flood damages in urban areas (houses, school, roads...) - creation of a touristic area for the inhabitants of Geneve canton. The area now benefits from a positive image which has a positive impact on tourism. - landscape conservation

Ancillary benefits information:

Indirect benefits are: - benefit for farmers by selling products on their farm from this increasing number of visitors - employment (agritourism, works)

Costs investment:

23600000

Costs capital:

22000000

Costs capital information:

Investments financed by specific laws on renaturation

Costs land acquisition:

1600000

Costs land acquisition unit:

€ (total value)

Costs land acquisition information:

This amount was transferred from the renaturation department to the regional,agriculture promotion fund in order to finance compensations linked to losses of agricultural lands

Costs operation maintenance:

37000000

Costs operation maintenance:

Including: 15 million € for works financed by Cantonal renaturation fund 22 million € for functioning

Costs operational:

37000000

Costs total:

61000000

Compensations annual:

230000

Compensations annual information:

Total amount was of 1,6million€.

Compensations basis unit:

€/ha

Compensations basis information:

The price for compensations was: 1,6€/m2 for farmers (owners or not) And 819€/ha more for farmers who didn't sell their lands

Compensations scheme information:

Ecosystem improved biodiversity:

Information on Ecosystem improved biodiversity:

Seymaz renaturation have recreated a wetland habitat which acts as a refuge for fauna and is a resting place for migratory birds. Flora such as rubanier dressé, laí®che faux souchet, scrofulaire auriculée, samole de Valerand and lagratiole officinale can now be observed in the wetland. Such species are priority in Switzerland and concerned by specific action palns. Farm plants such as bleuet, épiaire annuelle, véronique luisante, linaire élatine, linaire bâtarde, renoncule scélérate and bident triparti are also observed. Seymaz river is also recognized as a nesting site for amphibians.

Ecosystem provisioning services:

Ecosystem water supply:

Ecosystem impact climate regulation:

No information available

Ecosystem erosion control:

Information on Ecosystem erosion control:

Infiltration in riverbeds is higher. Erosion is limited but enough for ecosystems.

Policy, general governance and design targets

Policy description:

The Seymaz renaturation project is part of the cantonal program which aims at improving ecological and countryside quality and reducing flood risk by managing peakflows.. Corresponding WFD pressures are: 4.1.2 Physical alteration of channel/bed/riparian area/shore of water body for agriculture 4.3.1 Flow diversions/hydrological alteration †“ agriculture 4.3.1 Flow diversions/hydrological alteration †“ agriculture

Policy pressure:

Policy requirement directive:

Policy impact:

Policy wider plan:

Wider plan type	Wider plan focus	Name	Comments
Local	Environment & Biodiversity	Renaturation framework Action Plan	The project aims at improving rivers ecological and landscape quality and reducing flood risks. Those requirements are mentioned by a federal legislation (Law on rivers amenagements in 1991 and ordonance on water protection in 1998) and aimed by the program implemented by Geneve State (Renaturation framework Action Plan in 1999).
	Water

Policy area:

Policy target:

Target purpose
Improved Biodiversity
Runoff control
Increase Water Storage

Design & implementations

Application scale:

River

Installation date:

2005-01

Age:

Performance timescale:

1 - 4 years

Area (ha):

2920

Area subject to Land use change or Management/Practice change (ha):

400

Size:

5,09999990463257

Size unit:

Design capacity description:

About 800 000m3 can be retained in the treated area thanks to several NWRM and some other retention ponds.

Constraints:

Main contraints concerned land use, mostly agricultural lands, which was to be impacted by the project

Favourable preconditions:

Seymaz river basin used to be partly a wetland before being drained; natural hydrology could be restored

Management change from:

cereal cropping

Management change to:

natural land management

Outflow volume:

Outflow volume unit:

m3/sec

Peak flow rate:

15,5

Public consultation:

Design contractual arrangement:

Arrangement type	Role	Responsibility	Name	Comments
Contractual agreement			Contrats Nature	farm owners and farmers have received financial compensation, either for selling their land or keeping it and managing it respecting a †œnature contract†. The payment was function of the number of concerned hectares. Moreover, punctual compensations have been done, for instance during works periods and for a loss of three year yields during when land was leveled. Farmers also beneficiated for tax advantages. The State also created a fund for regional agriculture promotion, beneficiating for land sales. The renaturation department transferred 1,9million CHF to this fund.

Design consultation activity:

Activity stage	Name	Key issues	Comments
Design phase	Charte Seymaz
Implementation phase

Design land use change:

Land use change type
Natural grasslands

Design authority:

Authority type	Role	Name	Comments
Other	Financing	Grand Conseil and Conseil d†™Etat of Genève State	Responsible for voting two laws/programs on Seymaz renaturation
Local water authority	Initiation of the measure	Geneve Canton: Genaral Direction of Water, renaturation of rivers and banks service ; Genaral Direction of Nature and Landscape ; Agriculture and the environment Department	Responsible authority for the implementation of the renaturation program
Farmers	Determination of design details of the measure	Members of the Charte Seymaz group (all actors concerned by the project)	†œnegociation† group on the renaturation program
NGO
Local water authority
	Determination of design details of the measure	Members of the management group	Responsible for coordinating and managing the local arrangements

Last updated: 18 Jun 2015 | Top

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