EBRO DELTA Third Workshop on Flood Risk and Danube Delta, September 2011 Albert Rovira & Carles Ibáñez IRTA-Aquatic Ecosystems 0
Ebro Delta Work Plan Main aim is to mitigate the effects of sediment imbalance and climate change in the Lower Ebro River and its delta Relevant problems in the Ebro delta: Flood risk Sediment management Decrease in mean annual water yield Changes in the seasonal fluvial regime Decrease of flood frequency/magnitude Dramatic sediment deficit Construction of infrastructures (i.e. artificial levees, dikes, canals, roads, etc.) in the river channel and delta plain subsidence and sea level rise not compensated
Ebro basin management & planning Whole river basin Lower Ebro River Confederación Hidrográfica del Ebro (CHE) Confederación Hidrográfica del Ebro (CHE) Catalan Water Authorities (ACA) Management Plans Ebro Lower Delta: river Ebro basin: River and its Delta: Pla Sediment Whole Director basin: Management Plan del Hidrológico Delta de Plan l Ebro de la ACA Cuenca land (+IRTA) use del Ebro & urban (PHCE) planning Restore Water the Framework sediment continuity Directive (new of concept Europan of reservoir Union management) Minimize the sediment imbalance Stop the coastal retreat environmental Offset the elevation restoration loss (subsidence of the & sea Ebro level delta rise) Pla Integral de Protecció del Delto de l Ebre (PIPDE) This plan is mainly focused on hydraulic infrastructures and water quality control Little attention is paid on sediment Main management obstacles: and flood risk CHE Legal responsibility of sediment management is on side of CHE Agreement with Hydropower Companies to by-pass the sediment trapped into the reservoirs Incorporation to future basin Plan (PHCE) to be revised in 2015
Recommendations & lessons learnt from other Delta regions General recommendations Sediment trapped in reservoirs: definition and evaluation of the problem; design of a sediment management plan; monitoring guidelines and Recommendations these recommendations are incorporated in the SedMa Plan. Sediment aggradation in river channels and estuaries: definition and implementation of a sediment management plan; minimisation of sedimentation rates recommendations are included in the PIPDE; however the dredging protocols for navigation should be improved. The experience form other DeltaNet systems (Elbe, Danube) can be useful. Contaminated sediments: the main pollution problem (toxic sediments at Flix reservoir) is being solved through a restoration project. The experience of the Elbe estuary can be useful; especially in what concerns the technology for decontamination. Flooding risk: development of flood risk management programmes: prevention; protection; preparedness; emergency response; recovery and lessons learned flood risk plans exist at local level (ACA) and at basin level (CHE). Most of the recommendations are already included in these plans. The experience in the Elbe and the Vistula can also be useful for the Ebro Delta. Linking the flood risk plans and the sediment management plans is a challenge that should be considered in future plans.
Detailed recommendations for the Ebro delta A sediment management plan should be incorporated in the planning at basin scale, containing: a plan to deal with sediments trapped in reservoirs. Coastal regression and sea level rise could be mitigated by means of ecological engineering measures such as wetland and dunes restoration, construction of small dikes, enhancement of vertical accretion in the delta plain, etc. Flood mitigation in the lower Ebro River and delta should be improved through a better planning of urban development and the restoration of floodplains. Main lessons learnt from other DeltaNet partners Danube Delta: the experience in floodplain restoration and integrated management of the natural areas. Elbe Estuary: The Elbe has a strong experience in the management of sediment that can be useful in some cases for the Ebro; especially the contaminated sediment. Vistula Delta: Potentially there could be some experience in flood management that could be interesting for the Ebro. Minho Estuary: the experience in food risk and sediment management in this system is low, so it is difficult to extract some lessons to be applied in the Ebro. Severn Estuary: there has not been chance for exchange of experience and learning from this case.
Work Plan Actions 20000 0 20000 Riu Cinca Area 1 Riu Segre Area 1 Mequinensa dam Area 2 Riba-Roja dam Riu Siurana Area 1 Flix dam Móra d Ebre Xerta Benifallet Area 3 Tortosa Amposta Area 4 0 20 km N
Work Plan Actions Area 1 - Construction of empiric models for suspended load and bedload in the main tributaries (i.e. Segre & Cinca Rivers) and the Ebro River. - Monitoring and sampling of the sediment transported in suspension. - Monitoring and sampling of the sediment transported as bedload. Area 2 - Analysis of techniques for remobilize and/or by-pass the coarse fractions through the reservoirs. The technical, economical and environmental viability of each technique also have to be analyzed. - Physico-chemical characterization of the sediment stored into the Riba-roja reservoir. - Detailed study of the operations to be performed in the Riba-Roja reservoir to by-pass or remobilize the sediment stored into the reservoir. - Construction of a mathematical model for the remobilization of sediment stored into the Riba-roja reservoir. - Pilot testing for validation and calibration of the mathematical model. - Study of turbidity currents in Mequinensa reservoir. Area 3 - Application and feasibility study through partial or total emptying of the Riba-Roja reservoir during natural floods. - Study of possibilities of restoring the bedload flux and definition of tasks to be performed. - Sediment injection pilot test in different parts of the river channel. Area 4 - Development of a model of sediment transfer through the irrigation network canals of the delta plain. - Pilot tests consisting of injecting fine sediment in some areas of the irrigation canals. - Pilot studies on the generation of organic matter in renaturalized rice fields. - Study on the role of green filters in renaturalized rice fields.
Actions in short term -Monitoring and sampling of the sediment transported in suspension and as bedload by means of the Network of Environmental Indicators of the Ebro Delta initiated launched in 2012 Participation of IRTA in collaboration of ACA and CHE - Sediment injection pilot test in different parts of the river channel planned for the end of 2011 or beginning of 2012 Participation of IRTA in collaboration of ACA Pilot studies on the generation of organic matter in renaturalized rice fields first phase (2009-2011) by IRTA, with the funding of the Spanish Ministry of Environment 2011 submitted a Life project. Participation of IRTA in collaboration of ACA. If approved (2012), the project would last three years. -Study on the role of green filters in renaturalized rice fields. 2009-2011 implemented at experimental scale by IRTA with the funding of the Spanish Ministry of Environment. Next phase implementation at real scale by IRTA. Duration: 3 years Other actions: Meeting with the President of the Basin Authority to present DeltaNet and discuss implementation of some actions included in the Basin Plan September 2011 Meeting with AcuaMed (Flix Reservoir) to explain the experience in the Elbe estuary Beginning of 2012
Actions in long term (2013-2020) Detailed study of the operations to be performed in the Riba-Roja reservoir to by-pass or remobilize the sediment stored into the reservoir. Construction of a mathematical model for the remobilization of sediment stored into the Riba-roja reservoir. Pilot trial and feasibility study through partial or total emptying of the Riba-Roja reservoir (flushing flood). Development of a model of sediment transfer through the irrigation network canals of the delta plain. Other actions: Incorporation of a new environmental flow regime for the lower Ebro River and delta (2015), according to the requirements of the Water Framework Directive. Development of a landscape model to simulate the effects of river floods and relative sea level rise in the Ebro Delta, as a tool to analyze future scenarios and propose management measures to mitigate the sediment deficit and the effects of global warming.
Thanks for your attention 9