Building a smart river solution for climate adaptation

Building a smart river solution for climate adaptation THE ROOM FOR THE RIVER PROGRAM & NOORDWAARD CASE

The Dutch created The Netherlands during the Roman time The Netherlands during the Middle Ages The Netherlands in the 21 th century

Disastrous flood in Holland 1421 Fatalities, lost cities, lost lands, damage and evacuations

Serious flood risks in ‘ 93 and ‘ 95 Damage and evacuations

Room for the River : Outline • Aim of the Room for the River project: • Safety against flooding • Improving spatial quality • Assignment of the Dutch parliament: • completion in 2015, budget: $ 2. 6 billion • Not top-down • From stakeholders to shareholders

Possible solutions Present situation More space (room) for water Dike reinforcement

Milestones of the program Exploration phase - 2000) Identification phase – 2007) (1996 (2001 Planning phase (2006 – 2012) Implementation phase (2009 – 2016) Maintenance phase (2013 -. . ) Does the concept Rft. R work? Making the national Masterplan Elaboration of the Measures Building the Measures Management of the goals

Room for the River program project area with the 34 projects

Noordwaard: Depoldering 2000 hectares Area has never been reclaimed after 1421 flood. = Nature Park Biesbosch Area has been reclaimed after 1421 flood. = Profitable Agriculture

Aim of depoldering of the Noordwaard Safety: • 60 centimetre reduction in water level at upstream city of Gorinchem Improving other functions with high spatial quality • Current residents must continue to be able to live there • Economic viability for farmers (within or outside of Noordwaard) • Nature development • Stimulation of tourism

agriculture Nature Tourism: biking, hiking, canoeing, boating, museum Nature and cattle breeding agriculture

Daily 100 days a year 30 days a year 1 / 2000 years

New farms on elevated earth mounds 3 new bridges over 3 new stream channels Innovative hybrid dike-forest solution reduced dike crest elevation

View video Pumping stations elevated above flood level +3. 5 m ‘MSL’ Biking and hiking infrastructure

New dike section, hybrid nature based solution Wave reducing forest-dike combination 100 m width 1000 m length Clay-grass dike 1 m lower crest than ‘traditional’ design Wave reducing willow-tree plantations • >70% reduction of wave height in healthy willow forest • Deltares/RWS design achieves required 1/2000 safety standards, but over designed

Two year old willow forest 3 yearly maintenace cycle

Robust Nature Based solution 1. Self-sustaining and resilient 2. Trees grow above waterlevel 3. Wave energy on dike toe independent of incoming wave energy height 4. Accretes and stabilizes sediment. River Wave reduction is insensitive to water level increase. Dike Forest

Grienddijk – ‘willow forest dike’ under construction (August 2014) 13 september 2021

Grienddijk – ‘willow forest dike’ implemented (June 2017) Unprotected ‘traditional’ dike reinforced with concrete blocks 13 september 2021

13 september 2021

Lessons learned • Integrated design in strong collaboration with local demands • Flood protection, ecological en economical sound • From stakeholders to shareholders • Leadership on all levels • See the river system as a whole

Noordwaard, a smart river solution for climate adaptation