General National Id France_02 Site name Hermance river Summary Hermance is a French/swiss transboundary river. From 2006, in the frame of a transboundary river management program, the SYMASOL has been implementing restoration measures along river in order to decrease flood risk downstream, supported amongst other by Geneva Canton. The river mouth have been widenned, the river has been remeandered, 2,3km of the river have been renaturated and vegetation have been planted back on banks. The Mermes marshland water retention power has been exploited through the creation of a retention pond. In addition to flood risk reduction for a hundred houses, the renaturation and restoration of a path along the river provided social benefits: people happen to appropriate again their river. Light or indepth? Light NUTS Code Rhône-Alpes RBD code FRD Transboundary 1 Data provider Anaí¯s HANUS, ACTeon Source(s) Contrat de rivières transfrontalier du sud-ouest lémanique 2006-2012, Etude, bilan, évaluation et prospective, phase 1: état des lieux initial et final www.symasol.fr Contrat de rivières transfrontalier du sud-ouest lémanique 2006-2012, Etude, bilan, évaluation et prospective, phase 2: bilan technique et financier NWRM(s) implemented in the case study Re-meandering Stream bed re-naturalization Riverbed material renaturalization Natural bank stabilisation Longitude 6.273155 Latitude 46.271137 Site information Climate zone cool temperate moist Mean rainfall 1150 Mean rainfall unit mm/year Average temperature 10 Type Case Study Info Vegetation class Predominant vegetation classes are crops and forests Monitoring maintenance Monitoring impacts effects 1 Monitoring location In-Stream Monitoring parameters Water quality (pesticides, nitrogen and metals) is monitored. Water flow and ecological quality are measured punctually Monitoring upstream station There is a project of settling down a station upstream Monitoring downstream station HER 379 and HER380 Performance Performance impact estimation method Catchment outlet Performance impact estimation information Comparison to the state before the implementation of the measure Design & implementations Application scale River Installation date 2006 Lifespan 100 Age 6 Performance timescale 1 - 4 years Area (ha) 4320 Area subject to Land use change or Management/Practice change (ha) 7,5 Size 13,5 Size unit km Constraints No performance evaluation has been done after the measure was imlemented. Effects are hard to assess. Favourable preconditions Areas relevant to retain water have been identified; the Mermes marshland appeared as an interesting retention place. Management change from artificialised courses Management change to natural courses / change in management practices in order to improve water retention Crop rotation crops are mostly vineyards and fruit plantations without rotation Outflow volume 0,439999997615814 Outflow volume unit m3/sec Peak flow rate 42,5 Public consultation 1 Contractural arrangements 1 Design contractual arrangement Arrangement type Responsibility Role Comments Name Contractual agreement Contractual arrangements have been signed with private owners about banks management Contracts with private owners Design consultation activity Activity stage Key issues Name Comments Design phase Information letters Screening phase Private interviews Screening phase Public meeting Implementation phase Public meeting Design land use change Land use change type Water courses Design authority Authority type Role Responsibility Name Comments Local water authority Implementation SYMASOL Local water authority created to manage weter in the concerned watershed and impelement the River contract Monitoring Other Financing Canton de Genève DIAE swiss Canton of Geneva Lessons, risks, implications... Key lessons The case study provides an example of a bundle of measures which can be implemented to achieve several purposes; it does not gives much facts on biophysical impacts but provides interesting elements about succes and barrier factors; in this case as in many others, dealing with private owners in order to implement the measures on their properties have been the main difficulty. Financing mechanism 0 Financing difficulties 0 Success factor(s) Success factor type Success factor role Comments Successful coordination between authorities main factor Financing possibilities main factor Other main factor Financing Financing type Comments Sub-national funds Sub-national funds were provided by water authority (Agence de l'Eau) and other authorities (Conseil régional rhí´ne Alpes, conseil général Haute Savoie). Local funds Local funds are water authority funds (SYMASOL) and other local authority funds (Canton of Geneva, Thonon town) EU-funds: Rural development funds EU contributed through FEADER fund EU-funds: Cohesion and regional development funds It also contributed through PSADER fund Barrier Barrier type Barrier role Comments Attitude of relevant stakeholders main barrier The main barrier has been dealing with land property; private owners were not ready to give away constructible lands and even in the case of existing regulations, they would not take away their fences. Negociations with private owners had to be done. Attitude of the public secondary barrier At the beginning of the project, people were not convinced; after several achievements, they understand better. Other secondary barrier The property issue has been considered to late; it needs to be anticipated. Limited staff and consultant knowledge secondary barrier The design consultant was not aware of the local context in terms of vegetation for instance; it proposed to plant trees which were not adapted to the local climate Driver Driver type Driver role Comments Balancing different objectives main driver Local authorities decided to deal with their rivers management after some studies that showed the pressure of urbanisation and the need to restore water quality. They made a first preliminary dossier that led them to implement a River contract and create the SYMASOL Legal obligations secondary driver Objectives fixed by the SDAGE asked for implementing a management strategy Financing share Financing share type Share Comments European funds 3 View National funds 97 View Policy, general governance and design targets Policy description Main targeted problem is flood risk in urban areas downstream; erosion and habitats protection are also targeted Quantified objectives The objectives are renaturing 4,4km of artificialised river, improving water retention capacity of a 5ha marshland Part of wider plan 1 Policy target Target purpose Peak-flow reduction Increase Water Storage Erosion Control Improved Biodiversity Oher Societal Benefits Policy pressure Pressure directive Relevant pressure Policy area Policy area type Policy area focus Name Comments Policy impact Impact directive Relevant impact Policy wider plan Wider plan type Wider plan focus Name Comments Local Water Contrat de rivière transfrontalier Sud Ouest Lémanique The plan defines water maagement strategy on rivers located in a watershed Regional Water SDAGE Rhí´ne Méditerranée The SDAGE defines the main objectives and strategies necessary to reach the good status for water bodies in 2021 Policy requirement directive Requirement directive Specification Socio-economic Direct benefits information The main benefit is social: people walk along the river and walkaways enable them to link the two sides of the city. People seem to make again the river their own and to became more aware of river management issues. Costs investment 357800 Costs investment information 343800€ have financed the creation of retention areas along the Hermance river Costs land acquisition 64000 Costs land acquisition unit € (total value) Costs operation maintenance 237300 Costs operation maintenance About 96000€ have been spent for restoring the banks of the Hermance river and 1000800€ have been spentto restore and renature the riverbed. 134331€ have been spent for widenning a discharge section. 5128€ have been spent for implementing grass buffer strips in the vineyards above the river, 10 000e/year are spent on haying in retention ponds. Costs operational 211300 Costs operational information About 96000€ have been spent for restoring the banks of the Hermance river (9,63€/m), corresponding to about 16 000€/year during six years. 166800€ have been spent per year during six years to restore and renature the riverbed. 134331€ have been spent for widenning an discharging section, that is to say 22400€ per year. About 100€/year have been spent on supporting grass buffer implementation in the vineyards above the river Costs maintenance 26000 Costs maintenance information About 96000€ have been spent to manage the newly planted vegetation along the Hermance riverbanks. Moreover, haying in retention ponds require about 10 000€/year. Costs total 1831600 Compensations annual 2500 Compensations annual information About 14000€ have been received by farmers for income losses Compensations nr beneficiaries 3 Compensations nr beneficiaries information Farmers Information on Economic costs - income loss Famers have received indemnisations for yield losses Ecosystem improved biodiversity 1 Information on Ecosystem improved biodiversity The river renaturation, banks restoration and riverbed works have benefited to natural habitats; fish population status have improved along the river: it passed from disturbed to excellent in one station, and to good in another one, between 2002 and 2011. Moreover, new plants can now be observed along the river. Ecosystem impact climate regulation No information available Biophysical impacts Ecosystem erosion control 1 Water quality overall improvements Negative impact-WQ deterioration Information on Water quality overall improvements Water quality has decreased during the implementation of the measure, but his can be linked to other factors (pressures...). Only hydrobiological quality (downstream) and metals (mouth) have stayed at the same level. Soil quality overall soil improvements Not relevant for this application Full Context Collection(aka Doorway or Gallery) Case Studies Pathway(aka Context) Default view Area(aka Level or Site) ALL