Solutions for a resilient urban watersystem: the case study of Hoofddorp park

Abstract

Most urban water systems are poorly adapted to challenges as climate change and population growth. A resilient urban water system contributes to a sustainable environment and provides urban ecosystem serves for the city’s inhabitants. The current water management of Hoofddorp park, divided in a wander forest and fruit nursery, is an example of an urban water system which does not contribute to a sustainable environment. The aim of this research was to define how the water system of Hoofddorp park can cost effectively be improved to reach a resilient water system for the future up to 2050. The most resilient and cost effective measurement was selected using a Multiple Criteria Decision Analysis (MCDA), that includes a current state analysis and scenario analysis. The current state analysis showed that the soil at the fruit nursery is compact and the soil in the wander forest is partly contaminated. The water chemical and ecological water quality is low. The scenario analysis showed that besides the increasing pressure from climate change, developments around Hoofddorp park are expected to increase the use of the park. The criteria used for analyzing the measurements were: water flow, soil infiltration capacity, potential water storage, water quality, habitat quality, pollution stability, costs, and risk. Two weighing methods were used for assessing the measurements: the equal weight method and the SIMOS method. The weights assigned through application of the SIMOS method emphasized the importance of water quality and soil contamination and the low importance of cost and risk. The best scoring measurements were the implementation of natural banks, changing water courses to increase flow, remove a weir that is not in use, and change the management of the fruit nursery so that the soil can improve. The most resilient water system is reached by implementing additional measurements such as equalizing the target water level in the area, applying drainage by sand columns in the fruit nursery, and changing the petting zoo water management. The additional analyzed measurements including the implementation of drainage ditches, debris funded paths, increasing maintenance of the water courses, tree removal, and implementing a fountain did either not score well or lower than another measurement for the same purpose and are therefore not advised for implementation. The results of the MCDA are not sensitive to a bias of the specialists to low importance of costs because both weighing methods show similar results.