The Sigmaplan Flanders Updating the Flemish Sigmaplan : Large scale flexible and sustainable river management

Transcription

1 The Sigmaplan Flanders Updating the Flemish Sigmaplan : Large scale flexible and sustainable river management Waterwegen & Zeekanaal (W&Z) nv Waterways and Sea Canal

2 Agenda - Introduction : Waterwegen en Zeekanaal Sea Scheldt - The original Sigmaplan : Storm surges Details Current situation - Need for an update - The updated Sigmaplan - The future - Questions

3 Organisation Flemish governement Department of Public Works Waterwegen & Zeekanaal : independent agency (plc) Statement Run most of water ways and surrounding area in Flanders, taking into account all stakeholders Encourage multifunctional use of the water Ensure safety of water ways and safety on the water Manage flooding risk

4 The Sea Scheldt area 105 km tidal influence Around km2 3 million people The Scheldt basin 355 km source-to- mouth Around km 2 10,5 million people

5 - Tides amplifies because of the narrowing of the riverbed around the city of Antwerp - Tides go until the shiplocks in Ghent more then 150km upstream - Unique natural values connected to the sweet water tidal conditions 7 gemiddeld HW en LW Salty Sweet doodtij Dead LW low tide doodtij Dead HW high tide springtij Spring LW tide (low) Spring tide (high) springtij HW Vlissingen -1 Hansweert Antwerpen Dendermonde Gent afstand in km

6 Congestion by north-westerly storm Storm tide Rising water levels Flooding risk Date Water level in Antwerp (TAW) Rise by congestion over astronomical tide Severe consequences (damage) Combination with Rainwater runoff upstream The Netherlands United Kingdom Belgium France

7 Immediate cause 1953 (Dutch Deltaplan) ha flooded in Flanders 1976 january 3rd 2000 ha flooded in Flanders Goal Protection of the Sea Scheldt area against flooding with a probability of 1% per century (= once in years) Decision by the council , feb.,22nd - implementation of the original Sigmaplan

8 Sigmaplan 1977 embankment augmentation zone 1 : 11,00 m TAW embankment augmentation zone 2 : 8,35 m TAW Tidal barrier Oosterweel 13 flood control areas circa ha embankment augmentation zone 3 : 8,00 m TAW

9 Sigmaplan Need for an update - Safety Implementation 81 % of the 512 km planned embankment constructions along the Seascheldt and its affluents are completed 12 of the 13 flood control areas functioning 650 ha (1600 acres) largest flood control area Kruibeke - Bazel - Rupelmonde is under construction (end of construction 2013) Safety level storm with a yearly chance of occurence : 1/70 (7,83 m TAW): current situation 1/350 (8,24 m TAW): once CFA Kruibeke is finished 1/ (8,97 m TAW): with tidal barrier original goal, but put indefinitely on hold in 1985 based on a cost benefit analysis Final Result 2013 and onward Maximum safety level of 1/350

10 Sigmaplan Need for an update - IWM Immediate cause VN-Conference 1992 Rio (Agenda 21): national integrated water management Helsinki Agreement 1992: transboundary integrated water management Goal Develop, a water system manage and repair it Make sure the water system functions Scheldt estuary Collaboration The Netherlands - Flanders Long Term Vision Scheldt estuary (ambitions for 2030) Three main aspects (accesibility safety ecology) Flemish territory: Sea Scheldt : safety and ecology : updated SIGMAPLAN Dutch territory: accesibility Westerschelde - Oosterschelde

11 The updated Sigmaplan the making of Step 1 Data - Models Step 2 Buiding Blocks Step 3 Simulations Step 4 Social CBA Step 5 choice of optimal project Step 6 Detailed project implementation plan

12 The updated Sigmaplan main principle higher consequences low probability lower consequences high probability Risk = Probability * Consequence -Probability: flooding by overtopping or failing of an embankment -Consequence: damage in euro (material infrastructure, personal)

13 The updated Sigmaplan How To Make a sustainable river system taking into account the European directives on environmental conservation objectives Combine safety with ecological functions to minimise impact on current landuse Find areas along the river where current use has the least social benefit and develop a system of support for the agriculture sector Develop the local projects on a basis of local participation from an early stage to guarantee maximum social benefits for example : recreational opportunities Total cost estimate above 500 MEUR (2004) Phased investment and construction between Projects with most impact (highest benefit) in a first phase. Total area for nature (tidal and non-tidal) and FCAs : 5400 ha of which more then 5000 ha future nature area of which ha new tidal nature Flexibility : after 2030 with 5 reserved areas in case stormtides rise more then anticipated inn 2004 : 500 ha.

14 The updated Sigmaplan Phased investments

15 The updated Sigmaplan First phase 2010

16 Tidal nature in combination with a FCA CRT

17 The updated Sigmaplan September 2011 Land acquisitions slow the project considerably (especially areas with solely ecological goals) Temporary ( ) budgetcuts since 2009 Technical designs and building permits for all 2010 FCA local projects are ready at present. 4 of the local projects are under construction The construction of the rest of the 2010 local projects will start from 2012 onward, total area : 2500 ha Preliminary studies for 2015 local projects are started, total area : 1900 ha

18 Next step - Integrated Water Management Including the possible improvement of inland shipping Study underway to upgrade from CEMT IV to Va

19 End of the presentation Questions?