Delta Programme for Rijnmond-Drechtsteden
Rhine Estuary-Drechtsteden is a region with densely populated, increasingly compressed urban areas situated along river branches with surrounding rural areas. The population and economic value in this area located behind the dykes has grown enormously since the 1960s. To secure the social-economic and spatial developments for the long term, it is essential for these areas to be protected from the sea and from the high discharge of river water. At the same time, the port must remain well connected with both the sea and the hinterland. Finally, the availability of sufficient fresh water of good quality is vitally important for citizens, main ports and green ports. In an advisory report, the Rhine Estuary-Drechtsteden Steering Committee presents the preferential strategy for the challenges of ensuring water safety and a sufficient supply of fresh water.
Results
The standards for Rhine Estuary-Drechtsteden were re-established in 2013 and were for the most part tightened. Flood risk management is essential to guarantee healthy socio-economic development in the delta area. The starting point in this region is the current main water system, with its dykes, storm-surge barriers and river widening efforts. In the long term, spatial planning measures and evacuation measures, supplementary to prevention efforts, can increase security and make it more robust. Solid dykes and storm-surge barriers are necessary, but this requires made-to-measure work in order to realise it in a cost-effective manner while safeguarding spatial planning quality. To be able to design this made-to-measure work, spatial planning action perspectives have been developed to help incorporate the necessary measures in the cities and countryside.
The Rhine Estuary-Drechtsteden region comprises a large expanse of areas situated outside the dykes. A “Strategic adaptation agenda for areas outside the dykes” is being drafted for these areas that makes room for solutions tailored to each area.
The Rhine Estuary-Drechtsteden region contains both vulnerable buildings and networks of vital, vulnerable functions. The most vulnerable of them all is the supply of the electricity that is necessary for all other functions. A satisfactory disaster management effort is needed. The Security Regions are developing suitable contingency plans with this in mind.
Raising safety standards and the associated preferential strategy of the Rhine Estuary-Drechtsteden region has been extremely effective. The risk of flood victims has decreased by 85 per cent and the potential for economic loss has been halved. The extra costs of the preferential strategy easily outweigh this. The decision to continue building on the current flood risk management approach is creating a solid system in this region that is sufficiently flexible to welcome new developments.
Within the frameworks of the Delta Decision on Fresh Water, the Rhine Estuary-Drechtsteden region has opted for a solid freshwater supply along with innovation to make water consumption more efficient and to combat salinisation. Supply and demand are being brought into greater balance. The supply of fresh water in the Rhine Estuary-Drechtsteden region and in large parts of West-Nederland relies heavily on two supra-regional intake points that are fed from the main water system. To provide West-Nederland with sufficient fresh water in the long term as well, including during extremely dry years, the “Small-scale Water Supply” is being expanded in phases. At a later stage, a permanent east supply line to Central Holland might be necessary. This will also enable the region to take advantage of more economic opportunities. The Brielse Meer system, as well, will be made more robust through a number of minor measures. Finally, measures are necessary at the consumer level to reduce consumption.
To implement the concrete measures from the preferential strategies for Flood Risk Management and Freshwater Supply, the national government, provincial authorities, local authorities and district water boards will incorporate the relevant components from the preferential strategy into their own visions and plans. To make preferential strategies cost-effective and to realise the necessary spatial planning quality, collaboration is essential, including cooperation with the business community.
The implementation of the Delta Decision on the Rhine-Meuse Delta, a new set of assessment and design instruments for the dykes and greater flexibility in the planning and financing for flood risk management measures are all preconditions to ensure good implementation. Parties in the Rhine Estuary-Drechtsteden region will continue this collaboration, also following the decision-making process for the Delta Decisions.