Ecosystems-based approaches. Future or Fantasy? Kees Bons

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1 Ecosystems-based approaches Future or Fantasy? Kees Bons

2 Deltas in 20 th century Protection against flooding is driving infrastructure development and landscapes Design of flood protective measures is very often mono-functional engineering We are losing other functions Building in Nature

3 Delta Squeeze Growing population All land and water is in use or is exploited Resources are increasingly scarce Impacts of climate change and sea level rise Need for multifunctional solutions that combine safety, economy and ecology

4 Green Adaptation Concepts make use of ecosystem functioning to enhance safety, food and freshwater security, and protect livelihoods include and enhance ecosystem functions in an integrated approach to adapt to climate threats

5 Building with Nature To use the dynamics and services of the ecosystem to realize safety and combine functions with economic feasibility

6 Dutch historical 1000yr large scale land reclamation Marshland = building kwelders with nature on mud coast by growing saltmarshes Foto paesens-moddergat Effective low cost low tech method produces safety & productive habitats & more space Frisian Wadden Sea Coast

7 100 s km Dutch sandy coast protected long term with dunes stabilized by vegetation Effective low cost low tech method produces safety & valuable habitats & more space & drinking water Isle of Texel

8 Amsterdam 2010, Waterboard, RWS, Deltares: soft safe green flexible dike Nature development with longshore connectivity and regional relevance for recreation and as fish and bird habitat Hoorn depth and material variations create diversity, enhanced by natural settling and compaction. 80m wide, 30 km, along lake shore

9 2009 RfR programme Noordwaard Wave reducing forest-dike combi Fort Steurgat Clay dike will be lower than traditional design 100m wide Wave reducing willow-tree plantations Low cost low tech Deltares/RWS concept achieves required 1/2000 safety standards and will be constructed before 2015

10 H_s [m] Wave Height (m) Ground level (m) NAP Wave reduction by willow forest predicted by SWAN- VEG Predicted wave reduction by willow forest 70%-80% reduction in first 20 m (variant 2 en 3) Wave boundary conditions: Hs: 1,2m T: 4,8s h: stormvloed maaiveld 2,8m h: 2,0m boven griend 0) bare platform 1) 1 year forest 2) mix 1j-3j 3) 3 year forest x (m) Case AD00 Case AD01 Case AD02 Case AD Wave reduction is insensitive to water level increase m.+nap 3.75 m.+nap 4.0 m.+nap x [m]

11 Wadden Sea Soft Safe Dike: saltmarsh/dune/dike hybrid Vegetatie als golfremmer Wave reducing saltmarsh Super storm stable vegetated dune Existing dike Debate: Technical feasibility Cost-benefit Conflict with Natura 2000 Scale 500m wide 30km long Saltmarsh grows with sea level and maintains stability and safety Flexible, low tech, low maintenance cost, longshore connectivity Wadden Sea Lake IJsselmeer Afsluitdijk

12 Building soft eco levee with nature by reef, marsh, dune combinations marshes reefs Long term safety: Marshes grow with SLR

13 Continuum of concepts and designs Salt: Wadden Sea Fresh: Markermeer PPP: sustainable safety and multiple profits Rich Levee Oosterschelde! RfR Noordwaard! Soft solutions Hybrid hard-soft mix Hard solutions more space, more BwN, complex, more flexible, cost-effective less space, more BiN, straightforward, less flexible, extra investment

14 Mississippi Delta, The Dutch Perspective project after Katrina, in cooperation with USACE Upgrade levees Regrow marshes Stabilize marshes surge reduction levee ridge levee Input of sediment to restore balance into sediment buffer

15 Perspective is based on state-of-the-art models and combined Dutch (eco-)engineering expertise We tried to be creative and practical Storm surge reduction by Ridge Levee Restoring large areas of marsh by poldering principle Deltares develops world-leading models for (hurricane) simulation of hydraulics and morphodynamics (XBeach, Delft3D), for instance Chandeleur Island study

16 Mekong Delta near Bac Lieu Vietnam SPACE!? Nature RESILIENCE Productivity SAFE beyond monofunctional

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18 We can create cost-effective safety by BwN! But we need different thinking and different acting If we have time and space to work with nature, use it!; considering adjusting to SLR, we have time Allow dynamics and accept site specific nature of the BwN solutions; Nature takes its time, project planning and execution should be adapted; Biologist should join design and construction teams Accept and manage shift from construction cost to maintenance cost; Accept and allow involvement of new partners in design process; Manage request for new knowledge and new regulations; Rijkswaterstaat is starting eco-engineering group Ecoshape consortium, multi-million euro program, end 2012 We need more experts trained in new thinking, they need tools Challenge for Deltares, universities and applied education

19 Eco-dynamic design process highlights What can the project do for the ecosystem, what can the ecosystem do for the project? Think beyond compensation and mitigation Consider the regional ecosystem, what are logical solutions that fit and that contribute to the ecosystem? Interdisciplinary: disciplines join forces from the birth of first concept; Alliances: build and utilize connections between organisations, communicate; Share costs and share expertise, don t be possessive; More value does not necessarily imply more money: look for win-win solutions. Think in cycles and build knowledge base

20 Summary 1. Building with Nature = generic practical & effective solutions 2. Building with Nature = out-of-the-box development process, collaboration between thinkers & do ers, cycle between government science - market. 3. Building with Nature = happy marriage between ecological know-how, sustainability and modern concepts of maintaining safety. 4. Building with Nature = Deltares is developing and sharing know-how and is hub of network! 5. Building with Nature = Constant cycle of implementation and adaptation 6. Building with Nature = Need more links to water management and need implementation in core business