Background and request for advice
Soil subsidence is occurring in many parts of the Netherlands, and particularly in areas covered by peat meadows. Although subsidence has been taking place for centuries, it has intensified over the past hundred years owing to water level drawdown and scale economies. The rate of subsidence is far from negligible; in fact, in some places the soil is subsiding by a few centimetres a year.
Soil subsidence leads to numerous problems. For example, infrastructure and buildings subside, peat oxidation produces carbon emissions, and the quality of the water and soil biodiversity deteriorate. It also has an adverse impact on the use of agricultural land. The usual remedy, i.e. lowering the groundwater level, is not universally tenable in the long term. The Climate Agreement also stipulates that carbon dioxide emissions, including those from peat meadows, must be drastically reduced.
This Rli advisory report focuses on soil subsidence in rural areas of the Netherlands, and more specifically in the peat meadows of the 'Green Heart', an area of farmland and open landscapes bounded by the Netherlands’ four largest cities (Amsterdam, Utrecht, Rotterdam and The Hague, known collectively as the ‘Randstad’). Several complex challenges converge in this area. In addition to soil subsidence, there are the pressures of urbanisation in the Randstad conurbation, the demands associated with water management and agriculture, the generation of green energy, and the challenges related to leisure time activity, landscape management, and biodiversity.
Many different parties are working to tackle soil subsidence in the Green Heart area. Numerous projects, programmes and pilot studies are under way, but it has proved difficult to scale up the outputs. A comprehensive approach is lacking and administrative complexity makes governance difficult to organise. While a great many parties are tackling soil subsidence in the peat meadows of the Green Heart, a sense of inertia prevails. Various advisory reports, and foresight studies have been produced, but so far no fundamental choices are being made.
The Council will address the following main question:
What material and organisational choices must be made in relation to the adverse impact of soil subsidence in the peat meadows of the Green Heart area, given the various possible soil subsidence strategies (or combinations thereof) and how this issue relates to other challenges and demands in the area? Who is responsible for making and implementing those choices? And what role does the national government have to play?
The report will further address the following sub-questions:
- What is the nature of the subsidence problem and how serious is it?
- What material choices can be made in relation to the adverse impact of soil subsidence? How do choices regarding actions taken to counteract the adverse impact of soil subsidence relate to other challenges and demands in the Green Heart, such as urbanisation, agriculture, water management, and nature and landscape conservation?
- Which organisational choices should be made in addition to the material choices described in sub-question 2? Who is responsible for making these material and organisational choices, and what should the national government do?
- Will it be possible to apply some or all of the knowledge acquired with regard to counteracting the adverse impact of soil subsidence in the Green Heart to other peat meadow areas?
The advisory report is scheduled to be issued 3 September 2020.
Composition of the advisory committee
Ellen Peper, Council member and committee chairperson
Krijn Poppe, Council member
André van der Zande, Council member
External committee members
Gilles Erkens, geologist, Deltares/Utrecht University
Marcel Boogers, Professor of Innovation and Regional Governance, University of Twente/BMC Advies