Surmounting the polder

Abstract

This master thesis aims to turn the tide regarding current water management in the peat polder.
To reverse a century old habitude to drain land for agricultural purposes, causing subsiding land below sea level. Climate is changing with increasing temperatures, higher peak precipitation in winter, draught in summer and rising sea level. Peat polders in the Western part of the Netherlands are subsiding due peat oxidation as water levels are kept low. Polders have subsided below sea level and need to be pumped out as an annual surplus of precipitation causes the polder to fill up. In coastal zones pressure from the sea causes salt water to seep to the surface. These problems in combination with climate change, questions a livable future in the polder.
The primary objective of this research is to critically examine and propose alternative water management practices of polder ecosystems. By examining methods for tolerating presence of water within our living environment. The terp proves to be an interesting way of living in harmony with water of the past. Elements of the terp such as fluctuating water levels, following soil characteristics, adaptable housing, and use of waste as building material, provide solutions for an alternative water system in the polder. Implementation of these elements are illustrated by an animation, showing a variety of possibilities to grow out of the polder. A zoom in on a small portion of the Noord-Kethel polder is used as a test ground for a masterplan to show how conceptual ideas from the animation would be implemented in practice.
In the Design a new water system is implemented to allow bigger fluctuation, decreasing peat oxidation. Then, the concept of the terp is implemented into a design which consist of two phases. The first phase shows an increase of one meter in water level resulting in the adaptations to landscape elements. The second phase of the design is a continuation of the first, as a next meter of water level increase is implemented. In the second phase, current polder changes from a green open landscape to a blue open landscape with meandering green strings, creating a resilient landscape, ready for future changes. The design implements a change in mentality, in which inhabitants need to be willing to adapt.
The Design is an addition to the ‘adapt’ scenario of the Delta Program. By proposing a graduate change to current polder landscape, resilient land above sea level is created, providing new forms of housing, cultivation, and nature within the Dutch Delta. The approach is an anticipative way of interacting with water, similar to the Dutch approach in the Golden Age. The change of mentality in current polder landscape towards an adaptive landscape is a challenge that needs more research to accomplish the design.