During planning processes for dealing with flood risk management, the early identification of the economic and ecological benefits delivered by nature-inclusive solutions results in different choices.
The Natural Dutch Capital approach – which is based on the identification, valuation and capitalization of ecosystem services – is a useful method here.
Deltares and Alterra arrived at this conclusion on the basis of two pilot projects associated with the Eemshaven-Delfzijl dike upgrade and the Varik-Heesselt high-water channel.
The dike upgrade and the high-water channel are both part of the Delta Program. Between Eemshaven and Delfzijl, planners are considering a double dike with space in between for nature, saline agriculture and aquaculture, and a sludge motor between the two.
The channel will be created in the flood plain between Varik and Heesselt along the Waal River, reducing the investment required for dike upgrades in the upstream direction.
Three planning alternatives have been sketched out for the channel and they result in different space requirements.
The Netherlands Environmental Assessment Agency (PBL) asked Deltares and Alterra to explore the economic and ecological value of the different nature-inclusive solutions. The two partners drew on the Dutch Natural Capital concept (NKN), a TEEB-based approach for the successive identification, valuation and capitalization of ecosystem services.
The conceptual model was elaborated to produce a practical checklist. The researchers wanted to explore whether the NKN approach can help to establish nature-inclusive decision-making processes.
Different insights, different decisions
In the case of the Eemshaven-Delfzijl dike upgrade, the steering group of the project found that the valuation of ecosystem services and biodiversity that had been conducted established adequately detailed and properly founded economic and ecological arguments for the double dike.
That constituted a sound basis for the official decision to look further at the details of the multi-functional double flood-defense zone and to conduct a trial.
In the case of the Varik-Heesselt high-water channel, comparing the planning alternatives on the basis of ecosystem services and natural assets generates added value in terms of the exploration of linkage opportunities.
The quantification process helped to differentiate at an early stage between the different opportunities. Major benefits for nature have proven possible; there are almost no benefits for ecosystem services. There is support at the level of the provincial and principal authorities for a nature-inclusive design for the channel.
At present, the focus of the debate among local residents is primarily on the necessity for the channel and the location.
Inclusion of the approach in the High-Water Protection Program and MIRT
The participants found the pilot projects useful. They believe there is added value in establishing a picture at an early stage of the benefits of ecosystem services and the value for nature of alternative solutions for flood risk management.
Normally speaking, the planning preparation phase focuses on construction costs. The NKN analysis widens the understanding of the benefits and, on that basis, linkage opportunities for ecosystem services and nature can be fully included in subsequent analyses and ongoing planning.
The use of the NKN approach for flood risk management is expected to be limited as long as this approach is not part of the procedures included in the High-Water Protection Program and the multi-year infrastructure, spatial planning and transport program (MIRT).
The recommendation is to include it in existing procedures so that nature-inclusive solutions are always explored at an early stage in the planning process, and so that opportunities for biodiversity and ecosystem services are not neglected. The researchers have advised the Ministry for Economic Affairs to explore the possibilities in this area in collaboration with the parties involved.
This proposal fits in with the renewal of the MIRT.