WE2 - Turning point analysis of Rhine river policies

Step: Adaptation options
You are here: Home / Case studies / WE2 - Turning point analysis of Rhine river policies
case: WE2 location: Rhine basin (Netherlands) sectors: Water resources; Marine and Fisheries

Question

Which question has been addressed in this step?

Appraising options: What adaptation options should be chosen?

Case step navigator: click any node to select the respective step

Why has this question been chosen?

  • This step addresses whether adaptation pathways, or flexible options, can be identified that reduce the risk of crossing a threshold.
  • The previous turning point analysis shows through impact projections a risk for failure of reintroduction policies under future climate change.
  • Due to the lead time necessary, due to the length of planning and policy cycles, for implementing options, none of the options can be considered shortterm.

Which methods have been applied?

  • Adaptation measures, were grouped into were grouped into three strategic options. For each option time for implementation was estimated, depending on the number of necessary policy and planning cycles (4-6 years) before implementation. Estimates of the potential delay of threshold crossing in this case study is based on expert judgments. Two categories of delays were used: 1) delay of threshold crossing of one to several decades, 2) delay of threshold crossing for longer periods.

Why have these methods been selected?

    For the strategic options developed, the implementation of one option does not exclude switching to another option at a later date.

What results have been obtained?

  • Several adaptive strategies were identified.
  • Without adaptive action the management regime will have to transform its objectives and routines, by accepting extended periods of extreme low flows in the river, accepting a river without a sustainable salmon population and changing freight transport to railways or roads during extreme low flow events. If such developments are considered unacceptable adaptive action needs to be taken, by implementing one out of the (non-exhaustive) list of strategic adaptation options in the table below.

Reflections on this step

  • This step is limited to a first inventory of possible measures. In order to complete the analysis an iteration of the adaptive turning point assessment must be made. Each adaptive strategy thus can be evaluated in terms of delaying or avoiding possible turning points in the future. This assessment provides information for decision makers on priority setting.

Pathfinder

Details on this case study step




The table presents an overview of a non-comprehensive list of adaptation options.
Objective Adaptation option Short description
Mitigate frequency and severity of low flow events Infiltration in urban areas Infiltration of storm water runoff from roofs, roads, etc. instead of discharge through sewage systems.
Infiltration in agricultural areas Mitigate sealing and quick run off of soils through: - Improved land cultivation - Green zones and buffers - Organic farming
Dam outflow management The Rhine basin has more than 2000 dams. Outflow is usually managed for hydropower or flood control. Adaptation of management to mitigate low flows is possible
Creation of surface water retention The Rhine river lost 80-90% of its flood plains to embankments and normalisations. Restoration of flood plains creates retention capacity
Adapt rules of the game Change standards for shipping lane dimensions and dredging policy The shipping lane dimensions are maintained to comply with international standards. Adaptation of dimensions (narrowing, creating a deeper central sub-canal, changing dredging policies) are possible adaptations.
Change water temperature standard Water temperature in the 20th century increased with 1°C - 3.3°C depending on the river branch. Two thirds of this increase is attributed to point source discharge from industries and power plants and one third attributed to climate change. Current temperature standards are based on research in the 1970s on toleration limits of (cyprinid and not salmonid) fish. The maximum mean temperature was set at 25°C. In Germany the standard for maximum allowable temperature is 28°C. The Dutch policy is to maintain a standard for maximum inlet river temperatures of 25°C in the Netherlands, with the exception of extreme conditions. In those cases the limit is raised to a maximum of 28°C. Reduction of the maximal allowable water temperature will force point source polluters to reduce discharge of energy in the river.
Change sector objectives Redefine ecosystem objectives The salmon is an indicator species because it is at the top of the food web in the aquatic ecological system. Ecological restoration is aimed at creating better conditions for this ecosystem. An adaptation option is to accept changes in the species composition and to find other indicator species.
Use modal split Inland shipping is by far the cheapest mode of freight transport per unit of weight between Rotterdam and Duisburg. If thresholds are crossed other means of transport may become economically more adventurous.
Innovate in ships Develop ships with dimensions better adapted to low water levels (smaller, wider ships, new thrust systems).
Switch to non-irrigated agriculture Agriculture in the Netherlands depends on allocation of river water because the growing season has a rainfall deficit. But there are alternatives to river water, like local storage of winter rainfall excess, or changing to more drought tolerant cropping patterns.