General National Id France_12 Summary The Bas Rhin department is sensitive to muddy water flows occuring during Spring and early summer storms, which impact farmers and villages located downstream of agricultural plots. In order to reduce this risk, the Agriculture Chamber and the local authorities are working together to develop ways of combating these phenomena, which are harmful to downstream areas. Within this partnership framework, a diagnosis of the erosion and mudslides risks is carried out by the Alsace Agriculture Chamber at the commune level, and gives rise to proposals for concerted crop rotation (preventive measures) and soft hydraulic developments (curative measures). On the basis of these recommendations, the installation of hedges, weirs and grass strips is carried out by different project leaders depending on the territory (municipalities or intercommunal). Concerted crop rotation is coordinated by the Agriculture Chamber, and also allows for the gradual transition of some crops to no-till techniques, while the communities manage the implementation of soft hydraulic works. Reviewed by Fribourg-blanc Light or indepth? In-depth The in-depth description of the case study mnre_rex06_plaine_dalsace.pdf Location description The Bas-Rhin department is located in the North-East of France. The Rhine plain land-use is mostly dedicated to Spring crops with no landcover during winter. Crops are located on the top of the hills and on the slope, while villages lie in the lower land. NUTS Code Alsace RBD code FRC Transboundary 0 NWRM(s) implemented in the case study Buffer strips and hedges Longitude 7.686808 Latitude 48.682818 Site information Remarks The project covers a wide area, with several hundred towns and villages. Design & implementations Project scale Large Project scale specification The policy was conducetd over a long period in the region. Application scale Region Installation date 2008 Age 12 Design contractual arrangement Arrangement type Responsibility Role Comments Name Design consultation activity Activity stage Key issues Name Comments Design land use change Land use change type Design authority Authority type Role Responsibility Name Comments Lessons, risks, implications... Key lessons The combination of preventive measures (crop rotation, no-tillage cultivation) and curative measures have reduced the risk of mudflow. Success factor(s) Success factor type Success factor role Comments Attitude of relevant stakeholders main factor Financing Financing type Comments Barrier Barrier type Barrier role Comments Driver Driver type Driver role Comments Financing share Financing share type Share Comments Policy, general governance and design targets Policy description The Bas Rhin department is regularly subject to muddy water flows. These occur during Spring and summer storms on silty hills with Spring crops (beets, corn, etc.). Silt mobilized by rainfall on bare plots is carried downstream, where there are sensitive issues such as villages in the valleys (Figure 1). Mudflows impact both the receiving area (villages and local residents) and the emitting area (loss of soil for farmers). Several factors have led to an increase in the risk of this phenomenon occurring since the 1950s: Climate changes favouring heavier rains earlier in the season. The decrease in grassland (-44% cattle between 1979 and 2000) and the increase in agricultural areas with little coverage during Spring and early summer. Theimplementation of land consolidation actions leading to an extension of the field size and the removal of landscape elements (hedges, rural roads, embankments, etc.). Urbanisation is also accompanied by the artificialisation of soils (+1047 ha/year between 1984 and 2000) and the progressive removal of buffer zones such as orchards and meadows. As a result, the frequency of muddy water flows has increased, and they occur earlier and earlier in the season. Policy target Target purpose 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 Policy requirement directive Requirement directive Specification Biophysical impacts Information on runoff reduction The effectiveness of soft-hydraulic measures has been demonstrated by modelling of watersheds concerned with muddy casting phenomena. The visual observation of the various carriers of project confirms the retention of sediments by the soft hydraulic developments. The co-benefits of this work are landscape improvement, restoration of habitat for small wildlife, and softening of tensions between farmers and inhabitants of villages that have been impacted by past muddy water flows. The measures are also considered less expensive in the short term than the construction of mud ponds. Photo gallery Full Context Pathway(aka Context) Default view Area(aka Level or Site) ALL