2016 EMBANKMENTS 2.0 AS PART OF THE TRANSITION TO A ROBUST WATER SYSTEM PERSPECTIVE FOR THE FRISIAN PEAT AREA 2050 MASTER THESIS LANDSCAPE ARCHITECTURE WAGENINGEN UNIVERSITY COMMISSIONED BY WETTERSKIP FRYSLÂN BY ANNA-JET LEIJENAAR COLOFON COLOFON © 2016 A.J. Leijenaar, Landscape Architecture Group Supervisor wetterskip Fryslân : Wageningen University and Wetterskip Fryslân. Ir. B.Couperus E: [email protected] All rights are reserved. No part of this publication may be W: www.weterskipfryslan.nl reproduced, stored in a retrieval system or transmitted in any form or by any means, electronic, mechanical, photocopying, recording or otherwise, without prior permission of the author and Landscape Architecture Group of Wageningen University. This publication is written as masterthesis for the master Landscape Architecture of Wageningen University (course: LAR 80436) commissioned by Wetterskip Fryslân with help Noordpeil: from Noordpeil. Ir. E. van der Laan T: 0515-424048 Author: E: [email protected] BSc. Anna-Jet Leijenaar W:www.noordpeil.nl MSc student Landscape Architecture T: 0644085481 E: [email protected] Supervisor Wageningen University: Dr. Ir. Ingrid Duchhart Professor landscape architecture at Wageningen University Landscape Architecture Group T: 0317 484 056 E: [email protected] W: www.lar.wur.nl 2 In fulfilment of the requirements for the Master of Science degree in Landscape Architecture at the Wageningen University, Landscape Architecture Group. Author: Anna-Jet Leijenaar Student MSc Landscape Architecture Wageningen University Signature Date Supervisor and Examiner: Dr. Ir. Ingrid Duchhart Assistant Professor Landscape Architecture Wageningen University Signature Date Examiner: Prof. Dr. Ir. Adri van den Brink Chair Landscape Architecture Wageningen University Signature Date Reviewer: Dr. Ir. Rudi van Etteger Assistant Professor Landscape Architecture Wageningen University Signature Date 3 PREFACE PREFACE Deze masterthesis is begonnen vanuit een facinatie voor polderdijken, regionale keringen, in het Friese veenweidegebied. Na mijn stage bij Waterschap Friesland, leerde ik over de problemen in het Friese veenweidegebied omtrent het waterbeheer in combinatie met het huidige agrarische landgebruik. Ik zag potentie om polderdijken op andere manieren te benutten om zo bij te dragen aan oplossingen voor huidige en toekomstige problemen in het veenweidegebied. Beginnend bij het analyseren van zulke keringen op kleine schaal liep ik al snel tegen moeilijkheden aan: Hoe zat het watersysteem nu precies in elkaar? Waarom zijn ze eigenlijk aangelegd? En waarom onderhouden we ze nu nog steeds? Met zulke belangrijke vragen moest het roer om. In plaats van werken op gedetailleerd niveau stapte ik over naar de regionale schaal met belangrijke conclusies als gevolg. Een veel groter probleem bleek aan de orde met hier het eindrapport als antwoord. 5 jaar Wageningen komt hiermee ten einde, 5 jaar waarin ik mezelf heb kunnen ontwikkelen als landschapsarchitect. Ik wil Waterschap Friesland als opdrachtgever bedanken voor de kennis en ervaring. In het bijzonder Bieuwe Couperus voor de goede begeleiding gedurende de periode waarin ik aan mijn scriptie heb gewerkt. Daarnaast wil ik Bureau Noordpeil bedanken voor het zoeken en vinden van structuur in mijn verhaal en voor het faciliteren van een werkplek om mijn rapport af te kunnen ronden. Tot slot wil ik Ingrid Duchhart bedanken voor het geven van feedback gedurende het hele proces. 4 water system is present. Some pages are framed by a yellow GUIDE TO THE READER rectangle. This means that this page includes analyses results, extra information to understand further findings. CHAPTER 1 INTRODUCTION However, this information could be skipped. The first chapter introduces the subject; problems at the CHAPTER 5 GENERIC GUIDELINES Frisian peat area as a result of the current type of agricultural land use. The aim of this thesis, to find out what measures Now local measures to develop a robust water system are GUIDE TO THE READER TO GUIDE lead to regional embankments as part of a robust water extrapolated to the whole Frisian peat area. These local system, is explained. Also the main research and design measures result in generic guidelines or measures that questions are given. A design process is introduced which illustrate what measures are necessary to create a robust is a method to generate an answer to the main research water system at the Frisian peat area and how regional question and the design question. This design process will embankments can become part of this system. be elaborated at chapter 4. CHAPTER 6 DISCUSSION CHAPTER 2 PROBLEM ANALYSIS Within the discussion some important points are discussed. Chapter 2 inlcudes a comprehensive problem analysis to find Like the design strategy or the possible impacts of the out what causes lead to the current and future problems development of a robust water system on farmers or the at the Frisian peat area. This in order to understand what water management organisation; Wetterskip Fryslân. measures could be helpfull to design a robust water system. CHAPTER 7 CONCLUSION CHAPTER 3 ANALYSIS ON THE CURRENT WATER SYSTEM At the last chapter the main research question is being The current water system is the basis for new developments answered. Conclusions are being made about the measures according to the water system. If it is not understood how to develop a robust water system and their consequences the current water system functions, it is much harder to for different stakeholders. design measures that can improve the current system and problems related to this current water system. Therefore Appendice A represents a glossary. This glossary may be an analysis is given which elaborates the functioning of the helpfull to understand unknown terms. current water system. CHAPTER 4 DESIGNING A ROBUST WATER SYSTEM Within this chapter different scale levels are analysed. These analyses form the basis for measures that lead to a robust water system for the Frisian peat area that include regional embankments as part of such a system. Also measures at local scale are illustrated which show the transition of the current landscape to a Frisian peat area where a robust 5 CONTENT 2.2.1 The origin of climate change COLOFON 2 2.2.2 Effects of climate change on the Netherlands and the Frisian peat area PREFACE 4 2.2.3 Problem diagram climate change GUIDE TO THE READER 5 2.3 REDUCTION OF THE FRISIAN SYSTEM OF RESERVOIRS FOR SAMENVATTING 8 SUPERFLUOUS POLDER WATER 31 SUMMARY 9 2.3.1 Problem diagram reduction of the Frisian system of reservoirs 2.4 FIXED WATER LEVEL 35 1. INTRODUCTION 11 2.4.1 Problem diagram fixed water level 1.1 OCCASION FOR RESEARCH 11 2.5 PROBLEM ANALYSIS - CONCLUSION 38 1.2 KNOWLEDGE GAP 11 1.3 RESEARCH DESIGN 12 3. ANALYSIS ON THE CURRENT WATER SYSTEM 40 1.3.1 Problem definition 3.1 THE FORMATION OF FRIESLAND 40 1.3.2 Purpose statement 3.2 HISTORIC VIEWS OF THE WATER MANAGEMENT IN FRIESLAND 41 1.3.3 Research questions 3.3 CURRENT WATER MANAGEMENT 42 1.3.4 Research and design strategy 3.4 THE ROLE OF EMBANKMENTS 44 1.4 THE PERSPECTIVE OF THE RESEARCHER 16 3.4.1 Primary embankments 1.4.1 The functioning of nature as a basis for design 3.4.2 Secundary embankments 1.5 RELEVANCE 17 3.4.3 Regional embankments 1.6 STUDY AREA 18 3.4.4 Local embankments 1.6.1 Location 3.4.5 Protection of embankments 1.6.2 Type of land use at the Frisian peat area 3.5 IMPORTANT FUNCTIONS 48 1.6.3 Soil type at the Frisian peat area 3.5.1 Nature areas 3.6 THE NEW WETTERSKIP FRYSLÂN 49 2.PROBLEM ANALYSIS 22 3.6.1 Retain water 2.1 INTENSIFICATION OF AGRICULTURE 22 3.6.2 Water storage 2.1.1 Greenhouse gass emission 3.6.3 Water elimination 2.1.2 Costs of the water managment 3.6.4 Current Wetterskip Fryslân 2.1.3 Nutrient runoff 2.6.5 Safety plans 2.1.4 Problem diagram intensification of agriculture 3.7 PAST AND CURRENT MEASURES 51 2.2 CLIMATE CHANGE 27 3.7.1 Embankment recovery programm 6 3.7.2 Future proof water management 6. DISCUSSION 3.7.3 Green blue services 136 3.7.4 Peat area vision 7. CONCLUSION 3.7.5 Water area plans 138 3.7.6 KRW measures SOURCES 140 3.8 IMPROVED PROBLEM STATEMENT 55 APPENDICES 145 3.8.1 Current water management in Friesland A. GLOSSARY 145 3.8.2 Future water management in Friesland B. WATER LEVEL FLUCTUATIONS 146 C. IMAGES OF REGIONAL EMBANKMENTS 147 4. DESIGNING A ROBUST WATER SYSTEM 59 D. IMAGES OF LOCAL EMBAKMENTS 148 4.1 INTRODUCTION 59 E. PROTECTION OF EMBANKMENTS - MATERIALS 149 4.2 WHAT IS A ROBUST WATER SYSTEM? 59 F. SAFETY PLAN II 151 4.2.1 Carrying capacity G. SECTIONS 152 4.2.2 Necessity 4.3 APPROACH 61 4.3.1 Design process of a robust water system 4.4 SCALE ANALYSIS 63 4.4.1 Analysis on regional scale 4.4.2 Potential of the landscape 4.4.3 Analysis on local scale 4.5 STEP 8 - LOCAL VISION 100 4.5.1 Location of taking measures 4.5.2 Measures 4.5.3 The lake area - measures - schematic 4.5.4 Possibilities as a consequence of land use transformation 4.6 CONCLUSION 130 5 GENERIC GUIDELINES 132 5.1 STEP 9 - REGIONAL VISION 132 5.1.1 Regional vision - 2050 5.1.2 Conclusion regional vision 7 kleinere niet minder belangrijke regionale keringen waarvan regionale schaal dat is geanalyseerd waar bodemdaling SAMENVATTING 1000 kilometer in het veenweidegebied ligt. Deze kleinere als gevolg van veenoxidatie zich zal voortzetten. Dit heeft keringen beschermen onder andere landbouwgebieden ertoe geleid dat de focus is gelegd op een regio die in de Deze thesis geeft een toekomstmodel voor een robuust tegen overstromingen, gezien ze de Friese boezem, een toekomst nog enkele meters zal dalen bij ongewijzigd land- SUMMARY watersysteem voor het Friese veenweidegebied gericht op intern water opslag systeem in Friesland, scheiden van de en waterbeheer waarbij de waarschijnlijkheid van grote een adaptiever landgebruik en de toepassing van regionale lagere polders.