Climate (Ex)Change: Normative Tide Sustainable development of the Dollart estuary area
photo: Rijkswaterstaat
Climate (Ex)Change: Normative Tide Sustainable development of the Dollart estuary area
Final Report
Title: Climate (Ex)Change: Normative Tide Status: FINAL Date: 7th of June 2010
Authors: D.H. van de Dijk 298591 H.R. Geerling 297637 Study programme: Civil Engineering Hanze University Groningen
Project leading institution: The Centre of Applied Research and Innovation NoorderRuimte Supervisor: O.M. Akkerman Reader: D.A.A. Krol
Place: Groningen
Summary
Over the next 40 years (until 2050) the Royal Netherlands Meteorological Institute (KNMI) estimates an absolute sea level rise of between 15 cm and 35 cm. Between the year 2050 and 2300 a sea level rise is estimated between 35 cm and 2,5 m.
This sea level rise and the increasing demand to combine flood protection with other demands from society, like development in nature protection and tourism, forces stakeholders involved in water management to approach water related problems in a different way. Innovation in design, construction and the use of other materials is necessary.
This also applies to the Dutch-German border in the international Wadden Sea area. The Climate(Ex)Change: Normative tide project focus on the cross border Dollart region, as part of the Wadden Sea, and concerns the relation between flood protection, nature conservation and requirements for further utilization of the Dollart region.
Organizations involved in flood protection in the Netherlands are governmental bodies on different political levels. Flood protection in the Netherlands nowadays is characterized by a multi-layer approach in which not only prevention of a flood is important.
Dyke design in the Netherlands is based on the Guide on Sea and Lake Dykes. Important parameters for the design of dyke include water level, waves and water run-up and overtopping. The current dykes are audited on the base of the Hydraulic Preconditions and the Specifications on Safety Auditing 2006.
Provinces and municipalities in the Netherlands are responsible for spatial development plans. These plans reserve space (flood protection zones) in order to make future changes to the dykes possible. Spatial development plans furthermore define goals and strategies in terms of adaptation to climate change.
Organizations involved in flood protection in Germany are governmental bodies on different political levels. Most important for the Dollart region are the State of Lower Saxony and lower authorities. The approach towards flood protection includes preventive, technical and further precautionary solutions.
Nature conservation in both countries is strongly influenced by European Directives and international agreements. Legal statuses of the Dollart region include Natura 2000 area, wetland area according to the Ramsar convention, National park and UNESCO World Heritage.
The area is used and managed by a variety of stakeholders with different interests. Conflicts in requirements of these stakeholders exist. According to Dutch legislation on water management sustainability is important. This means that both water safety and nature conservation interests should be and are considered during planning and design of future development.
Summary 1 D.H. van de Dijk & H.R. Geerling
Content
Summary ...... 1 1 Introduction ...... 7 2 Research ...... 13 2.1 Approach ...... 13 2.2 Method ...... 13 2.2.1 Desk research ...... 13 2.2.2 Interviews with specialists ...... 14 3 Flood protection in the Netherlands ...... 17 3.1 History ...... 17 3.2 Organizations ...... 18 3.3 Policy and legislation ...... 19 3.4 Approach to climate change ...... 20 3.5 Implementation of European 2007/60/EC Directive ...... 21 3.6 Dollart region ...... 22 3.6.1 Organizations ...... 22 3.6.2 Prevention of flooding ...... 24 3.6.3 Technical conditions for auditing ...... 28 3.6.4 Auditing procedure ...... 30 3.6.5 Spatial development...... 34 3.6.6 Crisis management plan ...... 36 3.6.7 Existing facilities ...... 37 3.6.8 Future adaptations ...... 39 4 Flood protection in Germany ...... 43 4.1 History ...... 43 4.2 Organizations ...... 43 4.3 Legislation ...... 44 4.4 Approach to climate change ...... 45 4.5 Flood protection in the Dollart region ...... 45 4.5.1 Organizations ...... 45 4.5.2 Policy and legislation ...... 46 4.5.3 Existing facilities ...... 47
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5 Nature conservation in the Netherlands ...... 51 5.1 Organizations ...... 51 5.2 Legislation ...... 52 5.3 Legal status ...... 54 6 Nature conservation in Germany ...... 59 6.1 Organizations and legal framework ...... 59 6.2 Legal status ...... 61 7 Users ...... 65 7.1 Owners ...... 65 7.2 Navigation ...... 66 7.3 Tourism and recreation ...... 66 8 Conclusions and recommendations ...... 69 References ...... 72
List of annexes:
Annex I: Results safety audit primary flood defence structures 2006 Annex II: Results safety audit primary flood defence structural works 2006 Annex III: Zones designated according to Act on the National Park Lower Saxony Wadden Sea Annex IV: Overview flood protection in the Netherlands and Germany Annex V: Glossary
Content 3 D.H. van de Dijk & H.R. Geerling
List of figures
Figure 1: Dollart (Wikipedia) ...... 7 Figure 2: Strategy model Climate(Ex)Change: Normative Tide project ...... 8 Figure 3: Sea level rise in different climate scenarios (Nationaal Waterplan) ...... 20 Figure 4: Management area Water Board Hunze & Aa's (Hunze & Aa's) ...... 23 Figure 5: Contribution of gust bumps in wake height (Leidraad Zee- en Meerdijken) ...... 24 Figure 6: Water level development during a normative storm (Leidraad Zee- en Meerdijken) ...... 25 Figure 7: Aspects taken into consideration during the design of the crest height (Guide on Sea and Lake Dykes) ...... 27 Figure 8: Sections along the Dollart (HR 2006) ...... 29 Figure 9: Dykes where angle of incidence of 90° is conservative (Google maps) ...... 30 Figure 10: Results safety audit 2001-2006 (Primaire waterkeringen getoetst) ...... 30 Figure 11: Flood defence structure category a (Primaire Waterkering getoetst) ...... 31 Figure 12: Flood defence structure category b (Primaire Waterkering getoetst) ...... 31 Figure 13: Flood defence structure category c (Primaire Waterkering getoetst) ...... 31 Figure 14: Audit scheme dykes (VTV 2006) ...... 32 Figure 15: Run-up and overtopping (VTV 2006) ...... 32 Figure 16: Piping or heave (VTV 2006) ...... 33 Figure 17: Heave (VTV 2006) ...... 33 Figure 18: Macro instability inner and outer slope (VTV 2006) ...... 33 Figure 19: Micro instability (VTV 2006) ...... 33 Figure 20: Revetment instability (VTV 2006)...... 33 Figure 21: Foreshore instability (VTV 2006) ...... 34 Figure 22: Flood protection zones (Omgevingsverordening 2009) ...... 35 Figure 23: Sluices Nieuwe Statenzijl ...... 38 Figure 24: Administrative divisions of Germany (Wikipedia) ...... 44 Figure 25: Determination of design water level (Generalplan Küstenschutz Niedersachsen) ...... 47 Figure 26: Common Eider (Wikipedia) ...... 54 Figure 27: National Park Lower Saxony Wadden Sea (Nationalpark Wattenmeer) ...... 61 Figure 29: Two of three areas where Kwelderherstel Groningen focuses on (Kwelderherstel Groningen) ...... 65 Figure 28: Overview of owners of the salt marshes in the Dollart region (Grensoverschrijdende kansen voor kwelders in de Dollard) ...... 65 Figure 30: Recreation zones Wadden Sea (InterWad) ...... 66
List of tables
Table 1: Governmental bodies involved in flood protection in the Netherlands ...... 18 Table 2: Current flood protection laws and regulations in the Netherlands ...... 19 Table 3: Review levels and wave heights and period in the Dollart region ...... 28 Table 4: Current flood protection legislation in Germany ...... 44 Table 5: Current flood protection legislation in Lower Saxony ...... 46
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1
INTRODUCTION
Content 5
1 Introduction
This report concerns the Climate(Ex)Change: Normative Tide project (NT project) for the final thesis of the study programme Civil Engineering of the Hanze University Groningen. The final thesis is part of the 8th semester of this study and will take place from February 2010 till June 2010.
Over the next 40 years (until 2050) the Royal Netherlands Meteorological Institute (KNMI) estimates an absolute sea level rise of between 15 cm and 35 cm. This estimation is based on different climate scenarios with different assumptions regarding worldwide rise in air temperature (KNMI, 2006). Until 2100, the KNMI estimates a sea level rise between 35 cm and 85 cm. Between 2100 and 2300 a sea level rise between 1 m and 2,5 m is estimated.
Stakeholders involved in water management have to deal with these future circumstances in order to keep a safe environment for human beings, their property and nature. Furthermore coastal defence specialists should take into account the increasing demand to combine flood protection with other demands from society, like development in nature protection and tourism. This means that problems should be approached in a different way. Innovation in design, construction and the use of other materials is necessary.
This also applies to the Dutch-German border in the international Wadden Sea area. With the goal to establish an international platform, the project Climate(Ex)Change will start in August 2010. Within this project research will be carried out in order to find answers for practical questions coastal defence engineers come up with.
The research conducted in the NT project will form a base for further research in the Climate(Ex)Change project. The area of interest for the NT project is narrowed down to the Dollart (Figure 1) because this area is the most interesting in view of the combination of flood protection and nature development. Furthermore the Dollart region is a border area between Germany and the Netherlands, which makes it suitable for international comparison of both countries and for the exchange of knowledge.
Figure 1: Dollart (Wikipedia)
Introduction 7 D.H. van de Dijk & H.R. Geerling
The aim of the NT project is to get an overview of policy and legislation, regarding flood protection and nature conservation, that apply when changes have to be made (because of sea level rise) in the coastal area of the Dollart region. In order to establish this, flood protection standards, facilities and organizational structure in the Netherlands, Germany and Europe will be explored. Furthermore nature conservation and spatial development in the region will be examined. Important in the NT project is the overlapping area between flood protection, nature conservation and users in the area (Figure 2).
Figure 2: Strategy model Climate(Ex)Change: Normative Tide project
The main question that should be answered during the research in the NT project is:
“What is the relation between flood protection, nature conservation and requirements for further utilization of the Dollart region?”
Flood protection is defined as all (necessary) measures and policies for the prevention and/or for reducing the effects of flood events, which can cause adverse effect on human beings, their property and nature.
Nature conservation is defined as the efforts to preserve, restore and develop natural resources. Requirements for further utilization of the Dollart region include requirements regarding land-use in the Dollart region. The users concerned in this research are: agriculture navigation tourism
In order to focus on the right subject, the main question is divided into two sub-questions. The sub- questions are determined in such a way that the answers to these questions will form a base for answering the main question.
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The sub-questions are: 1. How is flood protection performed in the Dollart region in the German part of the region? in the Dutch part of the region?
2. How is nature conservation performed in the Dollart region in the German part of the region? in the Dutch part of the region?
Flood protection The current situation in flood protection in the Dollart area will be described. Important issues are the standards regarding the flood protection, the existing flood protection facilities, organizational structure of water management institutions. A description of the standards that are applied in both Germany and the Netherlands will be given. Important issues are: Definitions Loads Safety factors Design requirements
The background behind these issues will be explored.
Included in the existing flood protection facilities will be the following flood protection elements: Sea dykes and secondary dykes Polders Salt marshes Sluices Pumping stations
Important issues regarding the organizational structure of water management institutions in the region are: Responsibilities Duties Policies (International) cooperation
Nature conservation Nature conservation will be examined in order to create an idea about the current situation in nature conservation in the area. Important issues are organizations active in nature conservation, policies and legislation, and legal status of the area.
Implementation of European directives and the relationship between flood protection, nature conservation and the requirements of users of the Dollart region will also be explored while answering the two sub-questions.
Introduction 9
2
RESEARCH
Introduction 11
2 Research
This chapter describes the research method used in the NT project.
2.1 Approach The approach of the research carried out in the NT project is the assumption that in the future measures have to be made. As a result the question rises which laws and regulations, regarding flood protection and nature conservation, have to be applied when changes are made (because of sea level rise) in the coastal area of the Dollart region. This report tries to create an overview on this matter.
2.2 Method The research that is performed for the NT project consists of desk research and interviews with specialists.
2.2.1 Desk research The desk research consists of reading and analysis of laws, regulations and documents regarding flood protection and nature conservation applied on national level and more specifically applied on the Dollart region. The following documents are used during the research:
Flood protection – the Netherlands Water Act (Waterwet) National Water Plan 2009-2015 (Nationaal Waterplan 2009-2015) o Management and Development Plan for National Waters (Beheer- en Ontwikkelingsplan voor de Rijkswateren) o Policy documents (Beleidsnota’s) Spatial Development Plans o Management and Development Plan for the Wadden Sea (Beheer en Ontwikkelingsplan Waddenzee) o Area Development Plans (Bestemmingsplannen) o Regional Development Plans (Provinciaal Ontwikkelings Plan) Crisis management plans (Crisisplannen) Management and Development Plan of Water Board Hunze & Aa’s (Beheer en ontwikkelingsplan Waterschap Hunze & Aa’s)
Flood protection – Germany Federal Water Acts o Federal Water Act (Wasserhaushaltsgesetz, WHG) o Federal Water Associations Act (Wasserverbandsgesetz, WVG) Regional Water Acts o Lower Saxony Water Act (Niedersächsische Wassergesetz, NWG) Spatial Development Plans o Lower Saxony Spatial Niedersächsische Raumordnungsgesetz Dyke Law (Niedersächsische Deichgesetz, NDG) Lower Saxony Disaster Response Act (Niedersächsische Katastrophenschutzgesetz, NKatSG)
Research 13 D.H. van de Dijk & H.R. Geerling
Nature conservation – the Netherlands Nature Conservation Act (Natuurbeschermingswet) Flora and Fauna Act (Flora- en Faunawet)
Nature conservation – Germany Federal Nature Conservation Act (Bundesnaturschutzgesetz, BNatSchG) Lower Saxony Nature Conservation Act (Niedersächsischen Naturschutzgesetzes, NNatG) Act on National Park Lower Saxony Wadden Sea (Nationalpark-Gesetz Wattenmeer, NWattNPG)
2.2.2 Interviews with specialists During the research specialists are interviewed about their expertise. The following experts are consulted: Mr. W. de Vries (legal specialist, Hanzehogeschool Groningen) Mr. K. Lentz (water management specialist, Water Board Hunze & Aa’s) Mr. P. Spekker (water management specialist, Landkreiss Leer)
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3
FLOODPROTECTION THE IN NETHERLANDS
Research 15
3 Flood protection in the Netherlands
This chapter concerns flood protection in the Netherlands and specifically the flood protection in the Dollart region. First the history of flood protection is described, after that concerned organizations, applicable policy and legislation, the Dutch approach to climate change and the degree of implementation of the European Flood Directive are treated. An overview of the legislation and policies and duties of organizations involved in flood protection in the Netherlands and Germany is given in Annex IV.
3.1 History This paragraph concerns the history of flood protection in the Netherlands. It is important to describe this because the laws, regulations and design specifications are based on the experiences in the past.
The relevant history of flood protection, for this project, starts in 1953. In the night of 31st of January 1953, the high water levels caused one of the biggest disasters in the Netherlands. In total 1836 people died and the total damage was estimated between 1,5 billion and 2,0 billion Guilder. After the disaster a Delta commission was installed to investigate the measures that should be taken to reduce the chance of repetition of such a disaster (Milieu- en Natuurplanbureau — RIVM, 2004).
As a result of the research new normative circumstances were defined in basic water levels. The commission considered assessing flood protection structures based on water levels with a repetition rate of 1/10.000 per year would reduce the probability of a dyke breach to the economical optimum, which was assumed to be 1/125.000 per year. These basic levels concern the western coastal area of the Netherlands. For the rest of the coastal area of the Netherlands a repetition rate of 1/4.000 per year was considered to be sufficient. Depending on the economical value of the land behind the dyke, an economical reduction factor is applied and the result is a design water level (Milieu- en Natuurplanbureau — RIVM, 2004).
Around 2000 a new approach towards water problems was introduced because of the increasing river discharge and the more extreme rainfalls. The new approach provides a policy that tries to reduce the (increasing) probability of flooding by retaining water, storing water and finally discharge of water. Also more space should be given to water (Cooperating Ministries, 2009).
In 2007 a new Delta commission was installed in order to perform research with the main goal to advise the Dutch cabinet about how to keep the Netherlands safe from the water in the future and how to adapt to the climate change until 2100. The advice, submitted in 2008, consists of twelve recommendations. The most important recommendation is that the safety level of the dykes in the Netherlands should be ten times bigger (Delta Commissie 2008, 2008).
As a result of the advice of the second Delta commission a more sustainable flood protection policy was introduced. This includes a multi-layer approach. The multi-layer approach consists of three layers of protection against flooding (Cooperating Ministries, 2009):
Flood protection in the Netherlands 17 D.H. van de Dijk & H.R. Geerling
Prevention of flooding The flood protection policy in the Netherlands concerns the prevention of a flood event as the most important layer of approach. The prevention of a flood is done by technical structures like dykes, dams and sluices. This first layer is described in Paragraph 3.6.2 till 3.6.4. Because a flood can never be ruled out, the next two layers focus on the reduction of the effect of a flood.
Realisation of sustainable spatial development Water related problems are taken into account in spatial development plans of the provinces and municipalities. Areas are reserved as retention areas and a section of free space is reserved along primary flood defence structures. The second layer is described in Paragraph 3.6.5. Crisis management The last layer consists of the improvement of the organization structure needed for the preparation for a possible flood and the management during a flood event. The third layer is described in Paragraph 3.6.6.
3.2 Organizations This paragraph concerns the organizations active in flood protection in the Netherlands.
The duties and responsibilities of the organizations active in flood protection are defined in three Dutch acts (Cooperating Ministries, 2009): Water Act (Waterwet) Water Boards Act (Waterschapswet) Environmental Management Act (Wet milieubeheer)
The organizations mentioned in these acts represent different bodies on various political levels as shown in Table 1. Name governmental bodies Working area Duty Government National Preparing and implementing national water policy Provinces Regional Preparing regional spatial development plans Municipalities Local Preparing local spatial development plans Water Boards Regional Performing regional and local water management Table 1: Governmental bodies involved in flood protection in the Netherlands
The government has the responsibility of the system. This means that the flood protection has to be organized in such a way that, by performing the defined tasks and taking the right responsibility, the goals of the water management will be achieved. In order to achieve this, the government develops a national water policy (Cooperating Ministries, 2009).
The provinces translate this national policy to a regional level and inform the government about the progress, the experiences and the difficulties encountered in the process (Cooperating Ministries, 2009)
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Municipalities and Water Boards are responsible for the implementation of the policy defined by the provinces. These bodies also inform the provinces about the progress of implementation and the difficulties encountered.
The management of the National Waters is performed by the government by means of the Public Works and Management (Rijkswaterstaat). Regional Waters are managed by the Water Boards (Cooperating Ministries, 2009).
The system of supervision is based on the Water Act. The government is supervising the provinces. The provinces supervise the municipalities and the Water Boards unless the interests in the problem or project are concerned to be super-regional or legally defined as international duties. Then the government has the right to supervise the Water Boards directly (Cooperating Ministries, 2009).
The Water Law defines a catchment approach for all water related problems. This approach, in most of the cases, results in involvement of different bodies were administrative borders are crossed. This stimulates the cooperation between the different stakeholders. During the preparation of the river basin management plans the same approach was tested successfully (Cooperating Ministries, 2009).
3.3 Policy and legislation This paragraph concerns the current flood protection policy and legislation in the Netherlands.
The current flood protection policy documents and laws in the Netherlands are shown in Table 2.
Title Level Water Act National National Water Plan 2009-2015 National Spatial Development Plans Regional/Local Management and Development Plan of Water Boards Regional Crisis management plans Local Table 2: Current flood protection laws and regulations in the Netherlands
Water Act The Dutch Water Act concerns the management of surface waters and ground waters and intends to improve the relation between water policy and spatial development (Helpdesk Water, 2010).
National Water Plan 2009-2015 The National Water Plan 2009-2015 describes the main policy of the government in the Netherlands about the water management. The National Water Plan focuses on (Cooperating Ministries, 2009): the protection against flooding the availability of clean and sufficient drinking water different types of water use
The government aims for sustainable water safety policy in the plan.
Flood protection in the Netherlands 19 D.H. van de Dijk & H.R. Geerling
Spatial Development Plans The spatial development plans are elaborated by provinces and municipalities. The plans describe the function and associated regulations for different parts of the land. In spatial planning water use and safety are taken into account, which can be seen as a sustainable approach.
Management and Development Plan of Water Boards The management and development plan of water boards describes the main policy of water boards, for the period of 6 years, regarding management and maintenance of the water related problems (Waterschap Hunze & Aa's, 2010).
Crisis management plans In the Netherlands crisis management plans are made by aid agencies (fire department, police and hospitals), governmental institutions (provinces, municipalities and water boards) and other institutions which are active in case of a disaster. The plans describe how to prepare and how to react in case of disaster.
3.4 Approach to climate change This paragraph concerns the current approach to climate change in the Netherlands.
Estimations on climate change for the Netherlands are done by two organizations: Royal Netherlands Meteorological Institute (KNMI) Second Delta Commission 2008
The estimations of both organizations are the same until the year 2050 (Figure 3).
Figure 3: Sea level rise in different climate scenarios (Nationaal Waterplan)
After 2050 the estimations differ from each other. The difference is the result of a different approach to the problem. The KNMI defines four climate scenarios based on changes in climate that are most likely. The Delta Commission 2008, in contrast, considers extreme scenarios based on results from IPCC researches and Dutch water safety and water management experts.
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3.5 Implementation of European 2007/60/EC Directive This paragraph concerns the current situation in the implementation of the European 2007/60/EC directive on the assessment and management of flood risks in the Dutch law.
The implementation of the EU flood directive in the Netherlands started in 2008. The first phase of the implementation consists of the legal implementation of the directive in the Water Act. The Water Act was accepted in December 2009 (Ministerie van Verkeer en Waterstaat, 2009).
Further steps consist of the physical implementation of the directive. This means first of all the preliminary flood risk assessment for each river basin district, or unit of management should be done. This assessment shall at least include (The European Parliament and the Council, 2007): maps of the river basin district at the appropriate scale including the borders of the river basins, sub-basins and, where existing, coastal areas, showing topography and land use; a description of the floods which have occurred in the past and which had significant adverse impacts including their flood extent and conveyance routes and an assessment of the adverse impacts they have entailed; a description of the significant flood events that have occurred in the past, where significant adverse consequences of similar future events might be envisaged.
The flood risk assessment should be finished at the end of 2011. Member States can decide not to do the preliminary flood assessment in case the Member States (The European Parliament and the Council, 2007): already did a risk assessment to conclude, before 22 December 2010, that a potential significant flood risk exists or might be considered likely to occur; decided, before 22 December 2010, to prepare flood hazard maps and flood risk maps and to establish flood risk management plans in accordance with the relevant provisions of the Directive 2007/60/EC.
After the preliminary flood risk assessment, the creation of needed documents and maps follows. In the end of 2010 it has to be decided (according article 13 paragraph 1b of the Directive) if the flood hazard maps, flood risk maps and flood risk management plans will be created. Member States are also allowed to use maps and documents created before 22 December 2010 instead. The provided content of these plans and information on the maps should be equivalent to the requirements set out by the Directive 2007/60/EC (The European Parliament and the Council, 2007).
Flood hazard maps shall cover the geographical areas that could be flooded according to the following scenarios (The European Parliament and the Council, 2007): floods with a low probability, or extreme event scenarios floods with a medium probability (likely return period ≥ 100 years) floods with a high probability, where appropriate
Flood risk maps shall show the potential adverse consequences associated with flood scenarios (the same as for the flood hazard maps) and shall express these consequences in terms of the following (The European Parliament and the Council, 2007): the indicative number of inhabitants potentially affected; type of economic activity of the area potentially affected; installations concerning integrated pollution prevention and control which might cause accidental pollution in case of flooding and potentially affected protected areas;
Flood protection in the Netherlands 21 D.H. van de Dijk & H.R. Geerling
other information that can be useful such as the indication of areas where floods with a high content of transported sediments and debris floods can occur and information on other significant sources of pollution.
Flood risk management plans shall include measures for achieving the objectives which have to be set according to the Directive Article 7 paragraph 2 of Directive 2007/60/EC.
The flood hazard maps and risk maps should be made available for consultation before the 22nd of December 2011 and the final version should be ready one year later. The flood risk management plans should be made available for consultation before the 22nd of December 2014 and the final version should be ready one year later (Ministerie van Verkeer en Waterstaat, 2008).
After 2015 the measures defined in the flood risk management plans should be executed. Before the 22nd of December 2018 the decisions, according to article 14 paragraph 1b, should be revised. The flood hazard maps and risk maps should be revised before the 22nd of December 2019. The flood risk management plans should be revised before the 22nd of December 2021. The revising of the maps and management plans should be done every 6 years after the first time (Ministerie van Verkeer en Waterstaat, 2008).
3.6 Dollart region This paragraph concerns the flood protection in the Dollart region on the Dutch side.
3.6.1 Organizations This paragraph concerns the Dutch organizations active in flood protection in the Dollart region.
Water Board Hunze & Aa’s The main organization in the Dollart region active in flood protection is the Water Board Hunze en Aa’s (Waterschap Hunze & Aa’s, WB Hunze & Aa’s). In their management plan it is described how the management of the flood defence structures and water management in the area is arranged until the year 2015. The main goal is to provide safety, clean and sufficient water for low prices with sustainability, natural balance, central environment and transparency as principles (Waterschap Hunze & Aa's, 2010).
The management area (Figure 4) of WB Hunze & Aa’s is located in the sub river basin Nedereems which is part of the international river basin Ems. WB Hunze & Aa’s is responsible the maintenance of the primary flood defence structure in the Dollard region, from Punt van Reide until Nieuwe Statenzijl. Furthermore research and planning is carried out in order to prepare for future changing circumstances due to climate change. In cooperation with the province of Groningen a report was established on the vision of the coast of Groningen in the future (Waterschap Hunze & Aa's, 2010).
In line with the national policy, the WB Hunze & Aa’s uses a multi-layer policy for the protection against flooding. Besides making sure that the primary flood defence structures meet the standards, also old flood defence structures can possibly be used to reduce the effects of flooding and emergency plans make sure that people and organizations are prepared for a flood event (Waterschap Hunze & Aa's, 2010).
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Figure 4: Management area Water Board Hunze & Aa's (Hunze & Aa's)
Since 2001 water boards in the Netherlands are obligated to perform a water assessment on spatial plans of provinces and municipalities. According to the Spatial Planning Act of 2008 it is not obligated anymore for provincial, regional and local spatial vision reports. The Water Assessment Process (Watertoets) includes, in an early stage, informing, advising, considering and valuing of water related aspects in spatial plans and decisions. Taken into account are issues, among others, like space for water, land height, covered area, flood defence structures and flood sensibility (Waterschap Hunze & Aa's, 2010).
Organizations in times of crisis As described before, the third part of the multi-layer approach consists of the improvement of the organization structure needed for the preparation for a possible flood and the management during a flood event.
In the Netherlands, emergency services are grouped in safety regions (veiligheidsregio’s). The Dollart region is included in the safety region Groningen. Organizations, which fulfil a role in times of disasters, cooperate and train together in order to be prepared for effective acting during major incidents or disasters (Cooperating emergency services, 2010).
The partners included in the safety region Groningen are (Cooperating emergency services, 2010): Municipalities located in the region Police departments Regional fire departments Medical Assistance for Accidents and Disasters (Geneeskundige Hulpverlening bij Ongevallen en Rampen, GHOR) Province of Groningen Water Boards Hunze & Aa’s, Noorderzijlvest and Fryslân Public Prosecutor’s Department Ministry of Defence
Flood protection in the Netherlands 23 D.H. van de Dijk & H.R. Geerling
Together these organizations elaborate crisis plans, which include the Regional Management Plan for Disaster Response (Regionaal Beheersplan Rampenbestrijding) and the crisis plans on municipality level (Gemeentelijk Rampenplan).
The most relevant organization, in view of this report, is the Water Board Hunze & Aa’s. The current crisis management plan is described in Paragraph 3.6.6.
3.6.2 Prevention of flooding As mentioned before (Table 2) the national regulation regarding the water management in the Netherlands is arranged by the Water Act of the 22nd of December 2009.
The general provisions of the Water Act define the river basin districts borders. The Dollart is included in the river basin of the Ems. Furthermore the dyke ring located in the Dollart region are defined, together with all the other primary defence structures in the Provinces of Groningen and Friesland, as dyke ring number 6. Safety standards define for dyke ring number 6 the average probability of exceeding per year of 1:4000 (Ministerie van Verkeer en Waterstaat, 2009). This means that the probability of exceeding the highest flood wave that a dyke should withstand is 1:4000 per year. The highest level is defined as the Normative Highwater level (maatgevende hoogwaterstand) or design (high water) level, in other documents sometimes referred to as review level. Another factor is defined as the probability of flooding due to the failure of the primary flood defence structure. Strength of the dyke and the extra height of a dyke (more than the normative high water level) are important for the protection against a flood. The probability of flooding is in principle lower than the probability of exceeding (Delta Commissie 2008, 2008).
Dyke design For the dimensioning of a sea dyke cross section, the following parameters are important (Technical Advisory Committee for Flood Defence in the Netherlands, 1999):
Design level and wave preconditions The design level and wave preconditions are described in paragraph 3.6.3 of this report. Wind gusts, storm oscillations and local winds Wind gusts, storm oscillations and local winds increase the water level. It is assumed that the effect of a wind gust is superior to the storm oscillations, so the effects of storm oscillations are included in the wind gust. The contribution of the maximum wind gusts (B = 0,50), in relation to the wave run-up, to the construction level is shown in Figure 5.
Wave run-up and wave overtopping Figure 5: Contribution of gust bumps in Wave overtopping occurs when the wave run-up level wake height (Leidraad Zee- en Meerdijken) is higher than the crest height. The wave overtopping is expressed in l·m-1·s-1. The Guide on River Dykes states that, in case of waves with a height of a few meters, the applied 2% wave run-up (value which is exceeded by 2% of the waves) results in a wave overtopping discharge of 1 l·m-1·s-1. In case of lower waves the wave overtopping discharge is equal to 0,1 l·m-1·s-1.
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The following discharges are defined as normative for the erosion of the inner slope (Technische Adviescommissie voor de Waterkeringen, 2002): 0,1 l·m-1·s-1 for sandy soil with a bad grass revetment 1,0 l·m-1·s-1 for clayey soil with a reasonable grass revetment 10 l·m-1·s-1 for a clay revetment and grass revetment which meet the standards
Current The current, as a hydraulic precondition, is not relevant for sea and lake dykes. Hydraulic loads due to ships Hydraulic loads due to ship movement are strongly dependant on the location. The loads are known by the management institutions. The current velocity, in general, does not exceed 2 m/s, the waves due to ship movement are not higher than 0,5 m and have a wave period between 2-5 seconds. This means that in general the loads due to ship movement are neglected during the design of sea and lake dykes. Development in water level during a storm in case of normative storm The following parameters are assumed regarding the water level development during a storm (Technical Advisory Committee for Flood Defence in the Netherlands, 1999): during the normative loads the shape of the water level development is evenly distributed along the coast the length of a storm in the Wadden area is equal to 45 hours the water level development during a normative storm is shown in Figure 6
Figure 6: Water level development during a normative storm (Leidraad Zee- en Meerdijken)
Wave preconditions during water levels lower than the design level The wave preconditions during water levels lower than the review level can be normative during the design of the revetment of the outer slope. The combinations of lower water levels and higher waves have to be researched (Technical Advisory Committee for Flood Defence in the Netherlands, 1999).
Flood protection in the Netherlands 25 D.H. van de Dijk & H.R. Geerling
Overpressure which can occur under the revetment In case the phreatic line in the dyke body is higher than the water level outside the dyke, overpressure can occur if the dyke revetment is completely or partly closed. The overpressure can result in shear or bursting of the revetment (Technical Advisory Committee for Flood Defence in the Netherlands, 1999). Other loads The group of other loads include (Technical Advisory Committee for Flood Defence in the Netherlands, 1999): Wind The direct influence of wind on dykes occurs in case sand from a beach in front of a dyke is transported to the dyke (by wind) and suffocates the grass revetment. Also buildings and trees transfer the wind load to the dyke. Ice In the Netherlands ice loads are not relevant during the design because the probability of a combination of high water levels and ice is small. Own weight Extraction from the sub soil Extraction of water, oil, salt, gas and others from the sub soil can influence the settlement of the area. This is taken into account during determining the crest height, even though it is not an actual load. Traffic The loads due to traffic are 13,3 kN/m2 on a width of 2,5 m. This is equal to heavy material and heavy trucks. Earthquake The chance of the combination of an earthquake and high waters is very small (< 10-4 per year) and is not taken into account during the design of dyke. Collisions, floating objects In case of storms the chance of a ship colliding with the flood defence structure is higher than in normal weather situations. The effects of such a collision, in such a case, are the biggest because the load of the ship hitting the dyke, high water levels and high waves can cause rapid enlargement of the damage. Deformations and deformations due to settlements Revetment should be able to cope with the deformations without losing the structural properties. If the revetment can’t cope with the deformations, the revetment will break or crack. Biologic degradation Plants and animals that live on the dyke can affect the dyke body. Loads due to waves and current can increase in case growth the roughness of the smooth revetment increases. Bituminous coatings are sensible for sheep and cow droppings. Animals like a rat or a mole can make holes and damage the dyke body. Chemical degradation Construction materials can be affected by oxidation, salt water or pollution. Climatic degradation Frozen water can affect the dyke body. Also long-term drought can dry a clay layer which is too thin and can affect the grass revetment.
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The design of a dyke can be divided into 5 different parts: design of the crest height design of foreland and foreshore design of outer slope and outer berm design of inner slope design of inner berm
The crest height is based on the design high water level, defined in the Hydraulic Preconditions 2006. Additional height is contributed by (Figure 7): sea level rise and subsidence due to gas extraction gust bumps, storm oscillations and local wind wave overtopping height local settlement and soil settlement
Figure 7: Aspects taken into consideration during the design of the crest height (Guide on Sea and Lake Dykes)
The foreland and the foreshore are important for the safety of the dyke. In case instability of the foreshore occurs, the outer slope can be affected as well. Flow slide in the foreshore can affect the stability of the entire dyke body. In general it is assumed that a wide, closed foreland has great value to the safety of the flood defence structure (Technical Advisory Committee for Flood Defence in the Netherlands, 1999).
The structure (material use) and the slope of the outer slope are important design features. The structure in most cases consists of a sand core with a clay layer. The slope is determined not only based on the stability of the structure, other factors like a berm can influence the slope as well (Technical Advisory Committee for Flood Defence in the Netherlands, 1999).
The inner slope is preferred to be 1:3 with a thin clay revetment on a sand core. The choice for the slope also depends on the space available. The slope should meet the requirements mentioned in Paragraph 3.6.4 of this report (Technical Advisory Committee for Flood Defence in the Netherlands, 1999).
An inner berm can be necessary in case of piping or if the macro stability of the dyke body is in danger. An inner berm should always be constructed because of the use during maintenance, dyke watch and disasters. The berm should be located 1 m above the mean high water level and should be around 4 meters wide (Technical Advisory Committee for Flood Defence in the Netherlands, 1999).
Flood protection in the Netherlands 27 D.H. van de Dijk & H.R. Geerling
3.6.3 Technical conditions for auditing Technical conditions for dykes are specified, by the Ministry of Transport, Public Works and Water Management, in the Hydraulic Preconditions 2006 (Hydraulische randvoorwaarden, HR 2006). The HR 2006 is part of the auditing procedure which is done every 5 year. After the period of 5 year, new knowledge, understanding and development make it necessary to revise the preconditions and a new auditing period is started.
The HR 2006 defines three types of phenomena that cause loads on flood defence structures, namely river discharge, tide and wind (Ministerie van Verkeer en Waterstaat, 2007). Relevant for the dykes in the Dollart region are tide and wind. Tide manifests in high water levels. Wind on the other hand can also cause high water levels (wind set-up) and waves. In special cases wind also causes gust bumps and storm oscillations. During the establishment of the HR 2006 it is assumed that the relation between water levels and wind speeds are strongly but not fully correlated.
This results in a probabilistic approach. This approach takes into account that not every combination of water level and wind causing extreme circumstances has the same probability of occurrence.
The normative water levels are determined on the base of measurements done in different stations. Wave specifications for the Wadden area, which includes the Dollart, is based on documents made in the seventies of the previous century. These were the most up-to-date data available during the establishment of the HR 2006.
The HR 2006 defines for dykes a review level for water levels. This review level is the water level defined by the safety standards and mentioned before as Normative Highwater level or design level. The review levels in the Dollart region are stated in Table 3. The sections are shown in Figure 8.
Section Review level [m + NAP] Wave height Hs [m] Tp [s] Tm-1,0 [s] 66 6,4 1,40 4,23 3,85 67 6,5 1,00 3,58 3,25 68 6,5 0,90 3,40 3,09 69 6,5 0,90 3,40 3,09 70 6,6 0,90 3,40 3,09 71 6,6 0,95 3,49 3,17 72 6,6 1,00 3,58 3,25 73 6,7 1,10 3,75 3,41 74 6,7 1,10 3,75 3,41 75 6,7 1,10 3,75 3,41 76 6,7 1,15 3,84 3,49 77 6,8 1,25 4,00 3,64 Table 3: Review levels and wave heights and period in the Dollart region
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Figure 8: Sections along the Dollart (HR 2006)
Waves caused by wind are defined in three specific characteristics:
Significant wave height (Hs)
Wave period (Tp, Tpm and Tm-1,0) Angle of incidence of a wave (ß)
For the Dollart region the wave heights are shown in Table 3. For reviewing the crest height the spectral wave period (Tm-1,0) is taken into account. For the stability of a dyke a wave peak period (Tp) is used and for the stability an average wave peak period (Tpm) is used.
In absence of data about wave period in the Wadden area, two equations are used for the determination of the wave period:
In these equations it is assumed that the slope of a wave is constant and equal to 0,05. The numbers in Table 3 are determined using these equations.
The angle of incidence is considered to be 90 degrees, according to the HR 2006, for all the Dollard primary flood defence structures. In case of a North-Western storm, the review level can occur in the Dollart region. According to a specialist of the Water Board Hunze & Aa’s, in this case the angle of incidence for the dykes south of Punt van Reide (Figure 9), the assumption of perpendicular impact is conservative. Discussions and further research has to determine the angle of incidence for this part of the Dollart dykes on the Dutch side.
Flood protection in the Netherlands 29 D.H. van de Dijk & H.R. Geerling
Figure 9: Dykes where angle of incidence of 90° is conservative (Google maps)
The previous mentioned hydraulic preconditions are valid until the year 2011 and will be replaced by new ones taking into account new knowledge and understanding of wave behaviour in the Dollart region and development like climate change.
3.6.4 Auditing procedure The last audit period of the dykes was between 2001 and 2006. This was the second time that the audit was performed. The results for all the primary flood defence structures of category ‘a’ and ‘b’ are shown in Figure 10. The different categories are described further on in this paragraph.
Figure 10: Results safety audit 2001-2006 (Primaire waterkeringen getoetst)
The diagram on the left, in Figure 10, shows the safety result of auditing the dykes and dunes included in category a and b. The results are (Inspectie Verkeer en Waterstaat, 2006): 44 % of the dykes and dunes in the Netherlands met the standards 24 % of the dykes and dunes in the Netherlands didn’t meet the standards For the rest the information was not sufficient enough to make a good judgment
The diagram on the right, in Figure 10, shows the safety result of structural works included in category a and b. The results are (Inspectie Verkeer en Waterstaat, 2006): 29 % of the dykes and dunes in the Netherlands met the standards 22 % of the dykes and dunes in the Netherlands didn’t meet the standards For the rest the information was not sufficient enough to make a good judgment
All the dykes and structural works in the Dollart region met the standards in 2006, as shown in the maps in Annex I and Annex II.
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Together with the Hydraulic Preconditions 2006, the specifications for safety audit 2006 (Voorschrift Toetsen op Veiligheid 2006, VTV 2006) form the base for the examination of the safety level of the primary flood structures in the Netherlands between 2006 and 2011. Height and stability of the structures are tested in these audits. The VTV 2006 describes the general assessment method (Inspectie Verkeer en Waterstaat, 2006).
The VTV 2006 divides the total system of primary flood defence structures into categories. In total four categories are defined (Ministerie van Verkeer en Waterstaat, 2007):
Category a The structures included in category a (Figure 11), are primary flood defence structures belonging to a system that encloses dyke ring areas and they provide direct protection against open water. The dykes in the Dollart region are included in category a flood defence structures.
Figure 11: Flood defence structure category a (Primaire Waterkering getoetst) Category b The structures included in category b (Figure 12), are primary flood defence structures positioned in front of dyke ring areas or connecting dyke ring areas and they provide direct protection against open water.
Figure 12: Flood defence structure category b (Primaire Waterkering getoetst) Category c The structures included in category c (Figure 13) are primary flood defence structures belonging to a system that encloses dyke ring areas and they don’t provide direct protection against open water.
Figure 13: Flood defence structure category c (Primaire Waterkering getoetst) Category d The structures included in category d are primary flood defence structures belonging to a system that encloses dyke ring areas (category a and c) or primary flood defence structures positioned in front of dyke ring areas or connecting dyke ring areas (category b) but located beyond the Dutch border. Further division is done by dividing the categories into sections. For each section the type of flood defence structure (dyke, dam, high ground, dune and structural work) is defined. Audit tracks for each section are defined as well. For the dykes in the Dollard the audit scheme is given in Figure 14.
Flood protection in the Netherlands 31 D.H. van de Dijk & H.R. Geerling
Figure 14: Audit scheme dykes (VTV 2006)
The failure mechanisms belonging to the audit tracks are defined in the VTV 2006 (Ministerie van Verkeer en Waterstaat, 2007): Run-up and overtopping (Figure 15), used for auditing the height Overtopping is the first failure mechanism that determines the crest height. The crest height should be higher than the review level. The crest height should also be high enough to make sure that the amount of overtopping is not too much and does not cause erosion of the inner slope of the dyke.
Figure 15: Run-up and overtopping (VTV 2006)
Instability by infiltration and erosion in case of overtopping, used for auditing the revetment After overtopping, water will infiltrate in the top layer of the inner slope of the dyke. The result of this infiltration is a saturated infiltration zone where the grain tension is lowered and the resistance against shearing is less. The instability of the top layer can be recognized by deformation and the occurrence of cracks parallel to the crest of the dyke.
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Piping (Figure 16), used for auditing piping and heave Loss of stability due to piping can occur when too many soil particles in the sub soil are taken by the seepage flow. This can be the case when (long-term) high water levels occur.
Figure 16: Piping or heave (VTV 2006)
Heave (Figure 17), used for auditing piping and heave Heave is the forming of running sand due to vertical outgoing ground waters.
Figure 17: Heave (VTV 2006)
Macro instability (Figure 18), used for auditing the marco stability of the inner and outer slope Macro instability in the inner and outer slope of the dyke is the shearing of big parts of a body.
Figure 18: Macro instability inner and outer slope (VTV 2006)
Micro instability (Figure 19), used for auditing the micro stability Micro instability is the loss of stability of soil layers with a very small thickness on the surface of the inner slope due to ground water flowing through the soil body. In these cases, a high phreatic line causes the problems.
Figure 19: Micro instability (VTV 2006)
Revetment instability (Figure 20), used for auditing the revetment The revetment on dykes protects the dyke body against erosion. The revetment can collapse by wave impact, water flowing parallel to the dyke and in special cases by static water pressure. In these cases the waves are able to attack the core of the dyke.
Figure 20: Revetment instability (VTV 2006)
Flood protection in the Netherlands 33 D.H. van de Dijk & H.R. Geerling
Foreshore instability (Figure 21), used for auditing the foreshore In case the foreshore of a dyke consists of weak clay or peat layers or softening sensitive sand, it is possible that large-scale shear and flow slide will occur on the foreshore.
Figure 21: Foreshore instability (VTV 2006)
Instability due to non water retaining structures, used for auditing non water retaining structures Non flood defence structures like buildings, pipelines or trees have a negative impact on the flood defence capacity of the flood defence structures. Per audit track a judgment is given and this judgement results in a score for each audit track. The scores per audit track are joined together and form the score for each section, as shown in Figure 14. The final score is equal to the lowest final score per audit track. The score per section will be translated into a final score, like: ‘good or sufficient’ which meets the standards ‘insufficient’ which doesn’t meet the standards
The final scores of all sections are combined together and form the safety judgement for each dyke ring area.
For ‘category a’ flood defence structures two final scores are given for each section. One based on the audit specification defined in the VTV 2006 and one based on the opinion of the water board responsible for the structure (Inspectie Verkeer en Waterstaat, 2006). The second score mentioned gives the management board the opportunity to deviate from the specifications of the HR 2006. The deviation should be well substantiated.
The third audit, for the period between 2006 and 2011, is not finished yet. Therefore the results are not known yet. The results will be published in September of this year. Because the hydraulic preconditions for the Dollart region are not up-to-date yet, it is important to get more knowledge on the loads due to high water levels. At the moment the water board is trying to collect data in order to use it for good analysis of the loads. A specialist of the Water Board Hunze & Aa’s has stated that it is still unclear if the dykes in the Dollart region will meet the standard. A critical point can be the grass revetment on the outer slope of the dyke.
3.6.5 Spatial development The province of Groningen has elaborated spatial documents for the province of Groningen. The Provincial Development Plan (Provinciaal Ontwikkelingsplan , POP) and the regulations regarding the spatial development (Omgevingsverordening 2009) are important for the Dollart region.
The POP contains the policy of the province regarding the physical living environment in the Province of Groningen. It is strategic and deals with the quality, the arrangement and management of the living environment (Provincie Groningen, 2009).
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Climate change is also an issue for the Province of Groningen. The POP describes that a lot of uncertainties exist about the effects of sea level rise in the province. The Province wants to adjust to possible changing circumstances in an early stage. It is expected, for the short term period (until 2015), that the climate change will not change the situation substantial. In this period the Province wants to prepare for coming changes and make minor changes to the existing flood defence structure. This includes to maintain the existing structure and if necessary to strengthen it, to increase the height and width of the dyke. These necessary measures to the flood defence structures are preferred to be in the direction of the sea. This saves land on the land side of the dyke and also living area located closely to the dykes can be retained. Adaptation in land direction will only be applied if the legislation prohibits the adaptation in the direction of the sea (Provincie Groningen, 2009).
In order to protect the land against floods, the Province wants to make protecting measures in a robust way. This means that the designs take into account future changing situations (sea level rise and subsidence). An existing situation should be easily adapted to new circumstances. Furthermore, the basis for further development of the region is to combine flood protection with economy, ecology, recreation and tourism (Provincie Groningen, 2009).
The POP defines, based on the maximum extreme climate scenario recommended by the KNMI and according to the third coast policy document (3e kustnota), sections of free space around the dykes. These sections are located around the dykes and reserve space for future development. The space reserved at the moment should be enough for the next 200 years. Also protection zones are defined. These protection zones define zones where no activities are allowed that can negatively affect the flood defence structure. These zones together form the flood defence zone (Provincie Groningen, 2009). The flood protection zone is shown in Figure 22.
In total the flood protection zones are 100 m wide. The flood defence zone is different for areas where housing is located and areas with no housing. The flood defence zones for these areas are defined as (Provincie Groningen, 2009): Built-up area: Section of free space (5 m) + built-up area (70 m) + protection zone (25 m) Non- built-up area: Section of free space (75 m) + protection zone (25 m)
Figure 22: Flood protection zones (Omgevingsverordening 2009)
Flood protection in the Netherlands 35 D.H. van de Dijk & H.R. Geerling
The regulations regarding these zones are first of all defined by the Water Board Hunze & Aa’s. The ‘Keur’ of the water board defines these regulations. The regulations prohibit certain activities in the mentioned zones. Because the water board is the responsible institution for the dykes in the Dollart region, it is assumed that getting a licence for adaptations to the dyke is not difficult.
The Province furthermore defines more regulations. In the section of free space it is not allowed to build unless it is necessary according to (strong) social interest and it is not (reasonably) possible to do it somewhere else. In the built-up areas it is allowed to build, in order to give a positive impulse but the building activities shouldn’t create an irreversible situation that prevents future adaptations to the flood defence structures (Provincie Groningen, 2009).
The regulations regarding the spatial development also state regulations regarding the activities in the flood defence zone. According to this document it is not allowed to build new structures other than structures that serve the primary flood defence structures or future primary flood defence structures within the section of free space. Also structures that can influence the stability of the flood defence structure negatively are not allowed to be built within the protection zone. Exemption could be granted in case of strong public interest and in case the measures can’t be done in other places (Provincie Groningen, 2009).
As mentioned before, in the near future (until 2015) no major changes to the flood defence structures are expected. Spatial plans and regulations take future adaptations to the dykes into account by defining flood defence zones along the primary flood defence structures located at the Dollart coast.
The municipality of Delfzijl has defined two spatial development plans for the Dollart region located within the borders of the municipality: development plan ‘Termunten-Termuntenzijl’ development plan ‘Eems en Dollard’
The most relevant plan, in view of flood protection, is the development plan ‘Termunten- Termuntenzijl’. This development plan includes the area of the dykes and the area on the landside of the dykes located along the Dollart coast within the borders of the municipality.
The development plan ‘Termunten-Termuntenzijl’ designated the function flood defence for the area of the dykes. The regulations regarding the function flood defence include the prohibition of building activities that are not necessary for flood protection. It is also forbidden to use ground and buildings for purposes other than flood defence. The municipalities may exempt activities.
3.6.6 Crisis management plan For the period 2009-2010, a disaster plan was made by Water Board Hunze & Aa’s. This plan consists of the description of the organization, the preparation and the method of acting in times of a disaster (Waterschap Hunze & Aa's, 2009).
The most relevant part of this plan, in view of this report, is the chapter storm surge warning and watch service (Stormvloedwaarschuwings- en wachtdienst). The service is important in case of high water levels. The service has to take measures to maintain the sea dykes and to provide the dyke watch services (Waterschap Hunze & Aa's, 2009).
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Data about water levels in the region are provided by measuring stations. The water levels can be reviewed by employees of the water board and an alarm can be given in case this is necessary. Furthermore the Public Works and Management (Rijkswaterstaat) has a Storm Surge Warning Service (stormvloedwaarschuwingsdienst, SVSD). This service provides data about expected storm events, 72 hours before the event (Waterschap Hunze & Aa's, 2009).
The plan also defines the procedure in case of alarming water levels. Stages of a (possible) flood event are defined, which include (Waterschap Hunze & Aa's, 2009): Informing the Regional Commander of Service (Regionaal Commandant van Dienst, RCvD): The Regional Commander of Service is head of the fire department. This stage is reached in case water levels until NAP + 3,80 m. The following actions are included in this stage (Waterschap Hunze & Aa's, 2009): Water levels are monitored by the head of the dyke watch (dijkbewaking); Closure of the defence structure in the harbour of Termunterzijl when water levels of NAP + 2,00 m are expected; Closure of the northern cut-off in Delfzijl when water levels of NAP + 3,00 m (NAP +3,57 m for the southern cut-off ) are expected. A pre-warning is given when the water level reaches NAP +2,60 m; Informing the chairman of the water board, the director of the water board and the province of Groningen about the high water levels (above NAP +3,00 m); Consultations with Water Board Noorderzijlvest and the German Storm Surge Warning Service (Sturmflutwarndienst).
Preparation stage: This stage is reached in case water levels are between NAP + 3,80 m and NAP +4,80 m. From water levels NAP +3,80 m the control centre is installed at the pumping station Rozema in Termunterzijl. The dyke watch teams start to inspect the dyke and close objects (sluices, culvert and pumping stations) located in the dyke. Also a mechanic is stand-by in order to repair installations if necessary.
Stage 2: This stage is reached in case water levels are above NAP + 4,80 m. From stage 2 the disaster plan will be used. The dyke watch is intensified and another control centre is installed in Veendam. An operational team will now make the decisions on necessary actions.
Stage 3+4: An operational team decides if a situation is bad enough to increase the level to stage 3 and 4. The scale of the disaster is big and the effects can be devastating.
3.6.7 Existing facilities The existing flood defence facilities in the Dollard region (on the Dutch side) are: dykes salt marshes sluices tidal culvert
Flood protection in the Netherlands 37 D.H. van de Dijk & H.R. Geerling
Dykes The management of the dykes in the Dollart region is the responsibility of the Water Board Hunze en Aa’s. The dykes function as the primary flood defence structure in the Dollart region. They prevent the flooding of the hinterland.
The KEUR 2010, the regulation document of the Board, defines the following maintenance duties (Waterschap Hunze & Aa's, 2010): keep the dyke clear of waste, objects and materials maintenance of the grass revetment recovery of small damages mowing of grass and bushes keep the damaging wild life of the dyke maintenance of vegetation and materials supporting the flood defence structure
Salt marshes The locations of the salt marshes in the Dollart area are shown in Figure 29. The salt marshes have two main functions: nature area flood defence function
Salt marshes are suitable for rare halophilous plants and birds that like to rest on salt marshes in times of high waters. Furthermore salt marshes reduce the maximum wave height and as a result of this the maximum wave impact on the dyke is lower.
Sluices Two sluices are located in the Dollart region, both in Nieuwe Statenzijl (Figure 23). The types of sluices are: a sluice gate and a lock. The sluice gate functions as a barrier against high waters from the sea side and to discharge waters form the polder behind the dyke. The discharge of water is done by gravity. The lock is used by ships to cope with the difference in water levels.
Figure 23: Sluices Nieuwe Statenzijl
Tidal culvert A tidal culvert is located in the dyke and connects the Breebaart polder with the Dollart. The culvert provides the possibility of a damped tidal movement in the polder behind the dyke. This creates a special nature area in the polder.
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3.6.8 Future adaptations Future adaptations to the dyke ring can make an Environmental Impact Assessment (EIA) necessary. The Act on Environmental Impact Assessment Procedure 1994 (Besluit Milieu-effectrapportage 1994) defines the activities that need an environmental impact statement. The activities included in the adaptation of the dyke ring that can be expected in the future and require an EIA are (Ministerie van Volkhuisvesting, Ruimtelijke Ordening en Milieubeheer, 1994): Construction of installations or structures in, on or above the sea bed or in the subsoil of the river bed excluding structures for needed for the extraction of oil or gas In cases the activity concerns an area of more than 1 hectare or more, or in cases the activity concerns heights of +100 m N.A.P. or activities concerning the construction of installations used for generation of energy by means of wind energy. Raising the sea bed including the creation of an island In cases the activity concerns an area of 500 hectares or more. Arrangement of rural areas In cases the activity concerns the transformation of function into nature, recreation or agriculture function with an area of 250 hectares or more excluding land consolidation. Construction of one or more recreational or tourist facilities In cases the activity concerns a facility or a combination of facilities which attracts per year more than 500.000 visitors or more, facility or a combination of facilities which concern an area of 50 hectares or more or facility or a combination of facilities which concern an area of 20 hectares of sensible area. Construction of a primary flood defence structure In cases the activity concerns the construction of a primary flood defence structure. Changing or extending of sea, delta or river dykes In cases the activity concerns changing or extending a sea or delta dyke with a length of more than 5 km or more and changing the cross-section of a sea or delta dyke of 250 m or changing or extending a river dyke with a length of 5 km or more. Reclamation of land and enclosure by dykes In cases the activity concerns an area of 200 hectares or more. The Minister of Housing, Spatial Planning and the Environment can waive the requirement for an environmental impact statement during the preparation phase. For flood defence structures this is the case, according to article 7.5 c of the Environmental Management Act, when the public interest makes it necessary to immediately do the activities described in the according decisions.
Flood protection in the Netherlands 39
4
FLOODPROTECTION GERMANY IN
Flood protection in the Netherlands 41
4 Flood protection in Germany
This chapter concerns flood protection in Germany and specifically in the German part of the Dollart, which is located in Lower Saxony. First the history of flood protection is described. After that organizations that are active in flood protection in Lower Saxony are explicated. Finally applicable legislation and the German approach to climate change are described. An overview of the legislation and policies and duties of organizations involved in flood protection in the Netherlands and Germany is given in Annex IV.
4.1 History After the Storm Surge of 1953 the government of Lower Saxony also took measures. In 1955 the flood protection program of Lower Saxony started. Dyke reinforcement of sea and river dykes and the building of 14 barriers in de deltas of Ems, Weser and Elbe were planned. Like the Netherlands Germany switched to precautionary flood protection. The highest possible water level was to be predicted beforehand instead of registered when it was too late.
In 1962 another storm surge occurred which struck Germany. Particularly Hamburg was flooded and damaged. After this disaster the Master Plan on coastal protection in Schleswig-Holstein was made.
In 1973 the Master Plan on coastal protection in Lower Saxony was made. The efforts undertaken since the disasters mentioned before were reviewed and further necessary precautionary safety measures were presented.
In 2007 a new Master Plan was made. New measures were necessary because existing dykes did not meet the requirements anymore due to settling and sagging of the land. Also expected sea level rise and an increased number of storms due to climate change were now taken into account.
4.2 Organizations Germany is a federal parliamentary republic of 16 states (Bundesländer).The federal government is concerned with flood protection on two fronts, two ministries have related responsibilities. The Federal Ministry for the Environment, Nature Conservation and Nuclear Safety and the Federal Ministry of Transport, Building and Urban Development.
Federal Ministry for the Environment, Nature Conservation and Nuclear Safety In terms of water management this ministry is responsible for implementing the European Flood Directive in German legislation. Preventive flood protection is part of this.
Federal Ministry of Transport, Building and Urban Development This ministry is concerned with (elements of) flood protection in terms of spatial development.
Flood protection in Germany 43 D.H. van de Dijk & H.R. Geerling
Figure 24: Administrative divisions of Germany (Wikipedia)
Most states, including Lower Saxony, are similar to countries like The Netherlands or Belgium considering their size and political structure, not to provinces like Groningen or Friesland. All federal states have their own laws on water management and safety within the framework of the federal government.
The districts (German: Kreise) have most administrative responsibilities in terms of flood protection. In the Netherlands the water boards have these responsibilities.
According to the Building Code (Baugesetzbuch) municipalities are in principle responsible for ensuring sufficient flood protection, as part of the general interest, for populated areas (NLWKN, 2007).
As different states face different challenges related to water management further details on lower level organizations in Germany vary per state. Every state has its own laws and organizational structure suited to its specific situation and conditions. The organization of flood protection in Lower Saxony which applies to the German part of the Dollart is elaborated in paragraph 4.5.
4.3 Legislation This paragraph concerns legislation that applies in Germany. Title Level Federal Water Act (Wasserhaushaltsgesetz; WHG) National Federal Water Associations Act (Wasserverbandsgesetz; WVG) National Table 4: Current flood protection legislation in Germany
These national laws provide legal frameworks for the German states.
Legislation on state level and lower is described in Paragraph 4.5.2.
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4.4 Approach to climate change Since the end of the 18th century water levels are recorded in Germany. Including land subsidence the mean high water level has increased 25 cm in the last 100 years. Especially the last 50 years the increase is significant. Considering sea level rise dykes in Lower Saxony were already designed 25 cm higher than necessary. Since 2008 an extra 25 cm ‘climate surcharge’ is added in dyke design. (NLWKN, 2007)
Scenarios of sea level rise based on studies by the IPCC are not very certain yet. The difference between minimal and maximal predicted sea level rise by the end of the 21st century is at least 18 cm and might even be 59 cm. So the actual sea level rise in the year 2100 could be 1 m or so, but it might as well be 41 cm (59 cm less than 1 m)(NLWKN, 2007).
Still, sea level rise is taken into account. In future plans and measures the following approach is adopted: Further investigations on sea level rise, storm strength and storm frequency are carried out; Foundations of constructive parts in the dyke will be constructed in a way that later heightening of the construction of up to 1 meter is possible; Dyke reinforcements can be created with a wider berm, so that further strengthening is possible in the existing dyke footprint; Annually a small part of the resources for flood protection is reserved for maintenance of the second dyke line.
It is important for future planning of flood protection that changes in sea water levels and the frequency and intensity of storm surges in the North Sea will be monitored continuously in order to improve scientific knowledge constantly (NLWKN, 2007).
4.5 Flood protection in the Dollart region This paragraph concerns German flood protection specifically in the Dollart region.
4.5.1 Organizations This paragraph concerns German organizations active in flood protection in the Dollart region.
The Dollart region in Germany is part of the state Lower Saxony (Niedersachsen). It lies in the district Leer. The local authorities are the municipalities of Jemgum and Bunde.
Lower Saxony state Ministry for Environment and Climate Protection The state Ministry for Environment and Climate Protection is responsible for legislation on water management and water safety in Lower Saxony. The state Ministry is the upper authority concerning the dykes in Lower Saxony. The state makes framework policy on coastal and flood protection. River basin approach (per catchment area) and conceptual plans for flood protection are perceived by the state.
Flood protection plans are based on the ‘3 pillars model’: Preventive flood protection: securing and recovery of retention areas and flood plains; Technical flood protection: construction of dykes, dams and flood retention basins; Further precaution: Improving warning services, building codes and risk prevention.
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NLWKN The flood barriers in Lower Saxony and the dykes on the Lower Saxony islands are managed and maintained by the states organisation for water management, coastal and nature protection (Niedersächsischer Landesbetrieb für Wasserwirtschaft, Küsten- und Naturschutz; NLWKN). The NLWKN also supports lower level authorities.
District Leer The district administration of Leer is the lower authority concerning the dykes around the Dollart. This means the district supervises the regional water associations and performs inspections of the dykes regularly.
The district is also responsible for designating flood plains. In the flood plains land use and construction can be restricted based on the state’s Water Act. This way damage as result of a flood event is limited.
Dyke Association Rheider Deichacht In Lower Saxony there are several water associations. These associations are somewhat similar to the Dutch water boards. However in Germany the water associations don’t have policy making responsibility. In the Dollart region a dyke association (Rheider Deichacht) and a sluice association (Sielacht Rheiderland) exist. Both associations are responsible for the same area, the Rheiderland, which is enclosed by the river Ems and the Dollart.
The Rheider Deichacht is responsible for maintenance of dykes in Rheiderland. It builds and maintains dykes in Rheiderland. (NLWKN, 2007)
Sielacht Rheiderland is responsible for dewatering the hinterland. The Rheider Deichacht and the Sielacht Rheiderland closely work together, they even share their office in Soltborg.
4.5.2 Policy and legislation This paragraph concerns policy and legislation that applies to flood protection in the Dollart region.
In the German part of the Dollart area the following laws and regulations on coastal and flood protection apply:
Title Level Lower Saxony Dyke Law (Niedersächsische Deichgesetz; NDG) State Lower Saxony Water Act (Niedersächsische Wassergesetz; NWG) State Lower Saxony Disaster Response Act (Niedersächsische Katastrophenschutzgesetz; State NKatSG) Table 5: Current flood protection legislation in Lower Saxony
Lower Saxony is the only state in Germany that has a Dyke Law.
Lower Saxony Dyke Law The NDG stipulates the height of main dykes as the sum of the expected maximum high tide (Design Water Level, DWL) and the local wave run-up. These normative values are determined by the competent dyke authorities, based on defined safety criteria(NLWKN, 2007).
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To determine the design water level the ‘deterministic single value procedure’ is used, which is different from the comparative or probabilistic procedure that is used in The Netherlands. In this method the least favourable values, not necessarily belonging to the same extreme event, for the following components in water levels are added: a) Height of Mean High Water (MHW) above reference datum (NN); b) Height difference between the highest springtide high water and MHW; c) Largest wind set-up (defined as height difference between the highest high tide high water and the associated astronomical tide high water);
d) Future secular sea level rise in 100 years. Figure 25: Determination of design water level (Generalplan Küstenschutz Niedersachsen) Component d) can be seen as a security surcharge.
Wave run-up is determined using mathematical wave models. Wave characteristics of the normative storm scenario are used to calculate the resulting wave height at the toe of the dyke. Based on this information and the design of the dyke, additional crest height for prevention of overtopping is determined .
4.5.3 Existing facilities Dykes The Lower Saxony Dyke Law defines two types of dykes. Dykes adjacent the open sea and estuaries are called main dykes (Hauptdeiche). Together with flood barriers, they protect the land from storm surges. Behind the flood barriers dykes, called protection dykes (Schutzdeiche), protect the hinterland from water that cannot flow to sea when the flood barriers are closed.
Grazing on the salt marshes reduces the amount of flotsam that drifts ashore and forms land wash of organic material on the dyke. This is important for the dykes around the Dollart because they are completely covered with grass. Land wash covering the dyke kills the grass, undermining the revetment. An important task of the dyke associations is to clear the washed flotsam from the dyke. All dykes on the German Dollart shore have a path on the sea side slope especially for removing flotsam.
Pumping stations Sielacht Rheiderland is named after the sluices (German: Siel; Dutch: Zijl) the association used to manage. Excess water from the polders flowed to sea trough these sluices. During low tide fresh water has been flowing out by gravity. Nowadays, due to subsidence, water levels in the polders are too low, compared to mean sea level, to use only gravity. Since the 19th century pumping stations are used to pump water to the sea.
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Storm surge warning service The NLWKN operates a storm surge warning service, which is stationed in Norden. The service monitors water level and wind data from the entire North Sea area. Thus the service knows about brewing storms in an early stage. They can predict water levels and timing of the storm. In case of an emergency, the affected communities and institutions are informed early and comprehensively so they can take appropriate precautionary measures.
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5
Flood protection in Germany 49 NATURE CONSERVATION NATURE IN NETHERLANDS THE
5 Nature conservation in the Netherlands
This chapter concerns nature conservation in The Netherlands.
In nature conservation three different visions can be distinguished (Wikipedia): Natural wilderness vision Classical or Arcadian nature vision Functional nature vision
The natural wilderness vision advocates the repair or reconstruction of self-regulatory primeval nature, sometimes called wilderness.
In the classical nature vision preservation of ancient cultural landscapes is important. These landscapes date from a time when human influence was less extensive and have important natural and aesthetic qualities.
The functional nature vision is about finding ways to combine nature with human activity.
5.1 Organizations This chapter concerns organizations involved in nature conservation in The Netherlands.
Organizations involved in nature conservation are: Ministry of Agriculture, Nature and Food Quality (Ministerie van Landbouw, Natuur en Voedselkwaliteit, LNV) Provincial authorities Het Groninger Landschap
Organizations that own land in the Dollart region are described in Chapter 7 of this report.
Ministry of Agriculture, Nature and Food Quality Dutch nature is home to 40,000 plant and animal species. The ministry makes policy and legislation providing for protection, maintenance and expansion of nature in the Netherlands. Wildlife policy of the Ministry of Agriculture is reflected in the following issues: Area Protection By protecting valuable nature areas rare species are given better chance to survive in the Netherlands. Area protection policy is focused on the national ecological network (Ecologische Hoofdstructuur, EHS), Wetlands, National Parks and National Landscapes and Natura 2000. Species Protection Because diversity of plant and animal species is not restricted to protected areas the Flora and Fauna Act protects species irrespectively of where they are. Biodiversity Biodiversity is in decline globally, including in the Netherlands. To preserve biodiversity conservation plans are made and the habitat approach is implemented.
Nature conservation in the Netherlands 51 D.H. van de Dijk & H.R. Geerling
The main principles for nature conservation policy are as follows. The government wants: A nice country to live and work in Protection of plants, animals and distinctive regions Sustainable use of key resources like water, space and biodiversity
Based on this the main goal is operated: ‘Preservation, restoration, development and sustainable use of nature and landscape as an essential contribution to a liveable and sustainable society.’
This goal must be read in an international context and explicitly holds a cultural challenge as well. It is about nature and landscape for and by people. The term nature is understood in a broad sense: ‘nature from front door to Wadden Sea’ (LNV, 2000).
In its policy and legislation the government implements directives from the European Union.
Provinces and RCW The Dutch provinces finance the acquisition and establishment of nature reserves. This way the National Ecological Network and Natura 2000 areas are developed. The provinces also support farmers and private landowners with nature conservation and protection of rare plants and animals.
Policy on the Wadden Sea is made by the provinces of Groningen, Friesland and North Holland, which are joined in a steering group (Stuurgroep Waddenprovincies), and with the national government, municipalities and water boards, joined in a regional board (Regionaal College Waddenzee, RCW).
The RCW has drawn up a management and development plan for the Wadden Sea area.
Common Wadden Sea Secretariat (CWSS) The three countries bordering the Wadden Sea, the Netherlands, Germany and Denmark cooperate in forming conservation policy. Delegates represent the countries in the Trilateral Wadden Sea Cooperation. The Common Wadden Sea Secretariat supports cooperation between the countries involved.
General policy, measures and projects are described in the trilateral Wadden Sea Plan (WSP). The latest WSP was signed in March 2010.
To monitor the extent to which goals are achieved the Trilateral Monitoring and Assessment Program (TMAP) is created.
5.2 Legislation This chapter concerns legislation concerning nature conservation in the Netherlands.
Nature Conservation Act (Natuurbeschermingswet) Based on the Nature Conservation Act areas are protected in three ways. An area can be designated (by the Ministry of Agriculture) as one (or more) of three types: Natura 2000 area Protected natural sanctuary (or monument) Wetland (Ramsar Convention)
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For designated areas a management plan is drawn by the authority that has the biggest interest in the area. Activities and interventions in protected areas are restricted to what is described in the management plans. For other activities that might affect nature in the area a permit is needed.
The European Wild Birds directive and Habitat directive are implemented in the Nature Conservation Act.
Flora en Fauna Act The Flora and Fauna Act provides for protection of plant and animal species. The European Wild Bird Directive and Habitats Directive are also implemented in the Flora and Fauna Act.
The law regulates management, hunting, trade and property and other human activities that are harmful for the protected species.
Protected species are: A number of native plant species All mammals that occur in the Netherlands naturally (except the Black and Brown rat and the House mouse) All birds that occur on the territory of the European Union All amphibians and reptiles All fish species (some excluded in Fisheries Act 1963) A number of other native species A number of exotic species
Species protection plans and Red Lists Species protection plans describe concrete actions to improve the habitat and living conditions of a species. These plans are carried out by the provincial authorities.
A Red List is a list of species that have become extinct or are threatened with extinction. These lists do not have a legal status. In order for a species to be protected it has to be included in the Flora and Fauna Act.
Léven in de Wadden The management and development plan for the Wadden Sea area is titled ‘Léven in de Wadden’ (Living in the Wadden area). The plan is drawn up by the national government, provinces, municipalities and water boards, represented in the RCW.
The plan includes policy and agreements. National policy is combined with wishes from the region. European Natura 2000 and the Water Framework Directive are also taken into account.
According to the key planning decision Wadden Sea nature is prioritized over human activity in the plan. Further on it is agreed that research will be done on new methods of coastal protection. The amount of water coming from the hinterland, the mainland, must be considered.
Another agreement is that maritime archaeological and historical cultural heritage must be preserved and used for recreation and education.
Plans describing concrete measures to be taken are yet to be developed.
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5.3 Legal status This paragraph concerns the legal status that the Dollart has in the Netherlands.
In 1984 the Wadden Sea, including the Ems-Dollart Estuary, is designated for inclusion in the list of Wetlands, Pursuant to the Ramsar convention.
As part of the Wadden Sea, the Dollart is designated as Natura 2000 area ‘Wadden Sea and North Sea coastal zone’. As result of this the status of ‘protected natural sanctuary’ is revoked from the Dollart.
In June 2009 the Wadden Sea was added to the UNESCO World Heritage List.
Wetland The List of Wetlands of International Importance, the Ramsar List, features wetlands located all over the world. Wetlands are designated by countries that signed the Convention on Wetlands of International Importance, the Ramsar Convention. These so called Contracting Parties, or Member States, have committed themselves to implement the ‘three pillars’ of the Ramsar Convention: Designate suitable wetlands for the Ramsar List Work towards ‘wise use’ of their wetlands Cooperate internationally
The Wadden Sea is one of the 1888 wetlands, which are spread over 159 countries that are on the Ramsar List.
Natura 2000 The Wadden Sea and North Sea coastal zone are designated as Wild Bird directive and Habitat directive area. As such it is part of the European Natura 2000 network. The following ecological values and features are distinctive for this area:
Presence of shallow sea water, intertidal mud flats and sandbars, annual pioneer vegetation with Samphire and other halophytic species, salt marshes with cord grass vegetation and different Figure 26: Common Eider (Wikipedia) types of dunes. Presence of the following species: Narrow-mouthed whorl snail, Lamprey, River lamprey, Twaite shad, Grey seal and Harbour seal (Common seal). (Dutch: Nauwe korfslak, Zeeprik, Rivierprik,Grijze zeehond en Gewone zeehond) Suitability as a breeding ground for thirteen species of birds: Spoonbill, Common Eider, Marsh Harrier, Hen Harrier, Avocet, Ringed Plover, Kentish plover, Little Gull, Great Tern, Common Tern, Arctic Tern, Little Tern and Short-eared owl. (Dutch: Lepelaar, Eidereend, Bruine kiekendief, Blauwe kiekendief, Kluut, Bontbekplevier, Strandplevier, Kleine Mantelmeeuw, Grote stern, Visdief, Noordse stern, Dwergstern en Velduil) Suitability as resting and foraging area for 39 species of birds: Grebe, Cormorant, Spoonbill, Bewick’s Swan, Tundra Bean Goose, Greylag Goose, Barnacle Goose, Brent Goose, Shelduck, Wigeon, Gadwall, Teal, Mallard, Pintail, Shoveler, Scaup, Common Eider, Common
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Goldeneye, Red-breasted Merganser, Common Merganser, Peregrine, Oystercatcher, Avocet, Ringed Plover, Golden Plover, Grey Plover, Lapwing, Knot, Sanderling, Curlew Sandpiper, Dunlin, Black-tailed Godwit, Bar-tailed Godwit, Eurasian Curlew, Spotted Redshank, Redshank, Greenshank, Turnstone and Black Tern. (Dutch: Fuut, Aalscholver, Lepelaar, Kleine zwaan, Toendrarietgans, Grauwe gans, Brandgans, Rotgans, Bergeend, Smient, Krakeend, Wintertaling, Wilde eend, Pijlstaart, Slobeend, Topper, Eidereend, Brilduiker, Middelste zaagbek, Grote zaagbek, Slechtvalk, Scholekster, Kluut, Bontbekplevier, Goudplevier, Zilverplevier, Kievit, Kanoet, Drieteenstrandloper, Krombekstrandloper, Bonte strandloper, Grutto, Rosse grutto, Wulp, Zwarte ruiter, Tureluur, Groenpootruiter, Steenloper en Zwarte stern)(LNV, 2008).
For these species to maintain it is necessary that the size and quality of the habitat is at least preserved or sometimes improved or increased.
The Ems-Dollart Estuary is not yet designated as Habitat Directive Area. Because it not clear where the national border between the Netherlands and Germany lies exactly, parts of the estuary are Dutch territory as well as German territory. This special situation demands close collaborations between both countries in order to effectuate the Natura 2000 status. Designation of the entire estuary will be done later.
A Natura 2000 management plan for the Wadden Sea is being developed. Public works and Management (Rijkswaterstaat) will publish the plan in 2011 expectedly.
World Heritage Introduction on the list of World Heritage Sites does not implicate extra legislation or measures. The fact that Wadden Sea is on the list shows that the area possesses unique nature values, that it is intact and that its protection is guaranteed.
Nature conservation in the Netherlands 55
6 NATURE CONSERVATION NATURE IN GERMANY
Nature conservation in the Netherlands 57
6 Nature conservation in Germany
This chapter concerns nature conservation in Germany. The legal framework and the corresponding governmental bodies that have responsibilities on this matter are described. Finally the legal status of the Dollart area is pointed out.
6.1 Organizations and legal framework This paragraph concerns the organizations active in nature conservation and legal framework for nature conservation in Germany.
Ministry for the Environmental, Nature Conservation and Nuclear Safety Nature conservation is, on federal level, the responsibility of the Ministry for the Environmental, Nature Conservation and Nuclear Safety (Bundesministerium für Umwelt, Naturshutz und Reaktorsicherheit, BMU). This ministry is also responsible for the federal flood protection in Germany (Bundesministerium für Umwelt, Naturshutz und Reaktorsicherheit).
The BMU can be divided into six Directorates which are responsible for different issues. The Directorate N for Nature Conservation and Sustainable Use of Natural Resources (Abteilung N: Naturschutz und nachhaltige Naturnutzung) is responsible for the conservation of nature and use of natural resources in combination with recreation and sport. Its function is to coordinate the works (carried out by states) and provide information about nature conservation (Bundesministerium für Umwelt, Naturshutz und Reaktorsicherheit).
The Ministry consists of three subordinate authorities which advice the Ministry if necessary. One of the subordinate authorities is the Federal Agency for Nature Conservation (Bundesamt für Naturschutz - BfN). The BfN is the central scientific authority at federal level for national and international nature conservation and landscape management. The main tasks of the BfN include (Bundesministerium für Umwelt, Naturshutz und Reaktorsicherheit): advising the Federal Government providing support for federal development programmes approving imports and exports of protected animal and plant species conducting research and awarding research assignments providing information about the results of its work
Furthermore the Ministry consists of eight independent advising bodies.
The BMU has elaborated the Federal Nature Conservation Act (Bundesnaturschutzgesetz, BNatSchG). This federal act provides the federal policy on protection, maintenance and sustainable utilisation of biodiversity.
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Lower Saxony state Ministry for Environment and Climate Protection On state level, the Lower Saxony state Ministry for Environment and Climate Protection (Niedersächsisches Ministerium für Umwelt und Klimaschutz, NMUK) is responsible for nature conservation. The goals defined by the NMUK are, to protect (Niedersachsisches Ministerium fur Umwelt und Klimaschutz): the capacity of the eco-system the viability of natural resources the flora and fauna and the diversity, uniqueness and beauty of nature and landscape
The Lower Saxony Nature Conservation Act (Niedersächsischen Naturschutzgesetzes, NNatG) defines the regulations for nature conservation in Lower Saxony.
The NNAtG defines for interventions in nature and landscape the regulations in §§ 7-16. It states the source of an intervention, if necessary, has to re-build the landscape in order to reduce the effects on the performance of the ecosystem or landscape value (compensation measures). An intervention is not allowed in case it causes effects on the performance of the ecosystem or the landscape value that couldn’t be avoided or compensated.
As a part of the NMUK, the Lower Saxony Organisation for Water Management, Coastal and Nature Protection (Niedersächsischer Landesbetrieb für Wasserwirtschaft, Küsten- und Naturschutz, NLWKN) is responsible for the management of coastal protection, flood protection and nature conservation. Department IV for Nature Conservation (Geschäftsbereich IV Naturschutz), based in Hannover, deals with the nature conservation. This office is the coordinating office for the entire state of Lower Saxony.
Furthermore the Wadden Sea National Park Authority (Nationalparkverwaltung Wattenmeer) exists. This authority is an independent authority directly under the supervision of the MNUK and is responsible for, according to the Act on the National Park Lower Saxony Wadden Sea (Nationalpark- Gesetz, NWattNPG), establishment of concepts for protection, development and care in the national park. Furthermore it is responsible, where lower nature conservation authorities (districts and city states) are not responsible, for: the exemptions and immunities of the NLPG limitations on use and entering of the area
Also the coordination of the work carried out by lower nature conservation authorities and providing of information and education are tasks of the National Park Authority.
Nature Conservation Agency of district Leer The Nature Conservation Agency (Amt für Naturschutz) is performing the role of lower nature conservation authority of the district Leer. It is responsible for the identifying protected nature areas (Naturschutzgebiet), nature monuments (Naturdenkmal), protected landscape areas (Landschaftsschutzgebiet) and protected landscape components (Geschützter Landschafts- bestandteil).
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6.2 Legal status This paragraph concerns the legal status of the Dollart region in Germany.
The Dollart region in Germany has been given three statuses: Natura 2000 area Wadden Sea National Park of Lower Saxony (Nationalpark Niedersächsisches Wattenmeer) World Heritage Site
Natura 2000 area In Germany, the states are responsible for the identification of the Natura 2000 areas. The Natura 2000 areas consist of areas protected in two different ways: protected areas based on the European Directives 92/43/EEG on the conservation of natural habitats and of wild fauna and flora protected areas based on the European Directive 2009/147/EC on the conservation of wild birds
The Dollart region is designated as Natura 2000 area. According to the NNatG article § 34c, plans and projects should be tested (before implementation) on the compatibility with the conservation goal set out for protected areas based on the flora, fauna and habitat Directive (FFH areas) and the bird Directive. The conservation goal is defined as the conservation and protection of the biodiversity in the area (Niedersachsisches Ministerium fur Umwelt und Klimaschutz).
Regulations for FFH areas are included in the Wadden Sea National Park Act.
National Park Lower Saxony Wadden Sea The Dollart region was designated as national park in 1986.
Figure 27: National Park Lower Saxony Wadden Sea (Nationalpark Wattenmeer)
Nature conservation in Germany 61 D.H. van de Dijk & H.R. Geerling
The area of the park can be divided into three separate areas (Figure 27): restricted zone (ruhezone) - 60,7% of the total area In this zone, priority is given to the protection of flora and fauna. In this area it is not allowed to enter the area without the use of hiking, riding or cycling paths. The nature shouldn’t be disturbed. Therefore it is not allowed to take anything what belongs to the nature out of the area and it is not allowed to leave anything what shouldn’t in the area. intermediate zone (zwischenzone) – 38,7% of the total area The typical landscape, most of all, is protected in the intermediate zone. It is allowed to enter the areas without limitations. Like in the sanctuary zone it is not allowed to disturb the nature. On salt marshes, in the breeding season, it is not allowed to enter without the use of designated paths. recreation zone(erholungszone) – 0,6 % of the total area The recreation zone is designated for the recreation of human beings. The Dollart area is designated almost completely as restricted zone, except the area around the former drilling rig located near Dyksterhysen. This area is designated as intermediate zone. A part of the designated areas in the Dollart are shown in Annex III.
According to §16 of the NWattNPG, the rules and regulations stated in the NWattNPG do not apply for: the execution of measures of public interest concerning water management with exemption of the construction of new dykes measures of dyke authorities (coastal defence) with exemption of the construction of new dykes maintenance and repair measures on the dyke foreshore, where it is needed according to the Lower Saxony Dyke Law
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7
USERS
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7 Users
This chapter concerns users of the Dollart and the Dollart area. Apart from flood protection and nature conservation other interests exist. Owners and users of the area, navigation and tourism and recreation are described.
7.1 Owners The area of on the sea side of the dykes consists of salt marshes and mudflats. The owners of the salt marshes and mudflats are shown in Figure 28 and are (Drijfhout, 2010): 1. private owners grouped in the association ‘Vereniging van Oevereigenaren en Gebruikers (VOG)’ 2. foundation ‘Het Groninger Landschap’ 3. society ‘Natuurmonumenten’ 4. National Park Lower Saxony Wadden Sea
The farmers united in the VOG, own or use (lease) the salt marshes and the dykes. Together with Het Figure 28: Overview of owners of the salt marshes Groninger Landschap and Natuurmonumenten the VOG in the Dollart region (Grensoverschrijdende kansen voor kwelders in de Dollard) works on a project to reform the management and use of the salt marshes in Groningen, see Figure 29. This project is called Kwelderherstel Groningen, which means ‘salt marsh repair in Groningen’. The main goal of the project is to increase biodiversity in the marshes. The way to achieve this is a more specific management strategy for different types of marshes. The lower parts, which are regularly flooded, can be managed extensively, allowing nature its own way. The higher parts can be grazed more intensively. With its measures the project Kwelderherstel Groningen also wants to guarantee the conservation of the marshes and to improve the recreational function of the marshes. Water Board Hunze & Aa’s is involved in the project. Kwelderherstel Groningen is financed by the Dutch government through the Wadden Fund (Waddenfonds).
Figure 29: Two of three areas where Kwelderherstel Groningen focuses on (Kwelderherstel Groningen)
Users 65 D.H. van de Dijk & H.R. Geerling
The area on the land side of the dyke is dominated by fields and nature areas. The fields are owned by farmers and use the fields either for their livestock or to growing crops. The nature areas are owned by the foundation ‘Het Groninger Landschap’.
7.2 Navigation The Dollart is too shallow for navigation. The Ems on the other hand is exploited by navigation. One of the biggest shipyards (Meyer Shipyard) in the world is located in Papenburg, a city located on the Ems. The depth of the Ems in its natural state is not deep enough for the big ships built in Papenburg. Therefore the Ems is dredged constantly.
Keeping the Ems on the desired depth has influence on the nature. The Dutch Wadden Sea Society (Waddenvereniging) considers the dredging activities on the Ems as the most important reason for the fact that the water is getting troubled and a result of this in some place the water gets oxygen- poor. Because the Ems is flowing along the Dollart area, the dredging activities also influence the unique brackish ecosystem of the Dollart area. The Dutch Wadden Sea Society started in 1999 a program to protect and restore the Ems-Dollart region. But the results are not satisfying.
Dredging activity also effects the tidal process. Because of morphological changes the hydraulic parameters change in the estuary. As a result of deepening the channel the tidal movement is less resisted. The water enters the estuary more easily and causes higher water levels. (Baptist, 2007)
7.3 Tourism and recreation The Wadden Sea, and the Dollart as a part of it, is divided in zones based on the impact of recreation on the nature. Three zones are designated to the Dollart region, show in Figure 30.
Figure 30: Recreation zones Wadden Sea (InterWad) These zones are: Recreation is allowed These zones are the zones were the effects of recreations on the nature are minor. Recreation is limited allowed These zones consist of areas, with important nature values, which will fall dry during low waters. No recreation is allowed These zones are the resting areas for seals and areas used by birds for breeding areas. In some cases the recreation is not allowed in specific periods (e.g. breeding season). Furthermore some kinds of recreation are not allowed in the Wadden Sea, for other activities a license is needed. Activities like jet skiing and the use of water scooters are not allowed.
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8 CONCLUSIONSAND RECOMMENDATIONS Users 67
8 Conclusions and recommendations
The goal of the research, described in this report, is to pinpoint relationships between flood protection, nature conservation and utilization in the Dollart region.
When the sea level rises measures have to be taken in order to sustain our safety level. Furthermore the water board recognises other social requirements like nature and recreation development. In this way the three themes mentioned above come together. Subsequently the relationships between the themes are important for sustainable development of the flood protection facilities in the region.
Sustainability is an important issue in legislation on safety and in spatial planning. This shows in the National Water Plan, which states that the government targets on sustainable development. Also in the Provincial Development Plan of Groningen sustainability plays an important role, especially regarding flood protection and water management. The province of Groningen wants to adapt to climate changes in a robust way, considering development of economics, ecology and recreation and tourism in safety measures.
The Water Act does not restrict sustainable development of flood protection. Future measures can or even should be planned and designed in such a way that besides flood protection also nature and tourism and recreation are stimulated.
The project ‘Kwelderherstel Groningen’ shows that different stakeholders with different interests can work together. Farmers and nature organizations developed one integrated management plan, in which also the water board is involved.
However conflicts between different interests can be expected. For example the Province of Groningen prefers necessary flood protection measures to be planned in direction of the sea where possible. Sea bound measures in the Dollart could be at the expense of salt marsh area. On the other hand land bound measures could be at the expense of living area or farming fields. When measures are required different interests should be taken into account.
Another example of conflicting interests is the influence of dredging in the Ems-Dollart estuary on the natural habitat and on water levels. Quitting or reducing dredging activities may have positive influence on nature development and water safety but will negatively influence navigation.
In general this report offers general considerations about sustainable flood protection. Further, more detailed investigation on existing interests and exact consequences of specific solutions for stakeholders is recommended.
Conclusions and recommendations 69
REFERENCES
Conclusions and recommendations 71
References
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Cooperating Ministries. (2009). Nationaal Waterplan 2009-2015.
Delta Commissie 2008. (2008). Samen Werken met Water.
Drijfhout, G. (2010). Grensoverschrijdende kansen voor kwelders in de Dollard.
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Provincie Groningen. (2009). Provinciaal Omgevingsplan.
Technical Advisory Committee for Flood Defence in the Netherlands. (1999). Guide on Sea and Lake Dikes.
Technische Adviescommissie voor de Waterkeringen. (2002). Technisch Rapport Golfoploop en Golfoverslag. Delft: NIVO.
The European Parliament and the Council. (2007). Directive 2007/60/EC of the European Parliament and of the Council on the assessment and management of flood risks.
Waterschap Hunze & Aa's. (2010). Beheerplan 2010-2015.
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Final Report Climate (Ex)Change - Normative Tide
ANNEXES
Final Report Climate (Ex)Change - Normative Tide
Annex I: Results safety audit primary flood defence structures 2006
Final Report Climate (Ex)Change - Normative Tide
Annex II: Results safety audit primary flood defence structural works 2006
Annexes
Annex III: Zone designation according to Act on the National Park Lower Saxony Wadden Sea
Final Report Climate (Ex)Change - Normative Tide
Annex IV: Overview flood protection in the Netherlands and Germany
Legislations and policies The Netherlands Germany Political level Organization Legislation and policy Political level Organization Legislation and policy Federal Federal Ministry for the Environment, Nature Conservation and Nuclear Federal Water Act, Federal
Safety and Federal Ministry Water Associations Act of Transport, Building and Urban Development National State
Lower Saxony Dyke Law, Ministry of Transport, Public Lower Saxony state Ministry Water Act, National Water Lower Saxony Water Act Works and Water for Environment and Plan 2015 and Lower Saxony Disaster Management Climate Protection Response Act States organisation for Public Works and water management, coastal
Management and nature protection (NLWKN) Regional District Province of Groningen Spatial development plans Landkreis Leer Water Board Hunze & Aa's Management and development plan of water Rheider Deichacht boards, crisis plans Sielacht Rheiderland
Local Local Municipalities Delfzijl and Local spatial development Municipalities Jemgum and
Oldambt plans, crisis plans Bunde
Annexes
Duties The Netherlands Germany Political level Organization Duties Political level Organization Duties Federal Federal Ministry for the Implementing the European Environment, Nature Flood Directive in German Conservation and Nuclear legislation and flood Safety and Federal Ministry protection in terms of of Transport, Building and spatial development Urban Development National State
Acting as upper authority Ministry of Transport, Public Lower Saxony state Ministry concerning the dykes and Preparing and implementing Works and Water for Environment and making framework policy national water policy Management Climate Protection on coastal and flood protection Managing flood barriers and Managing of national States organisation for the dykes on the Lower Public Works and waters and dykes on islands, water management, coastal Saxony islands and Management Storm Surge Warning and nature protection supporting lower level Service (NLWKN) authorities Regional District Preparing regional spatial Province of Groningen Acting as lower authority, development plans Landkreis Leer inspecting dykes and Water Board Hunze & Aa's designating flood plains Performing regional and Maintaining dykes in local water management Rheider Deichacht Rheiderland Sielacht Rheiderland Dewatering the hinterland Local Local Municipalities Delfzijl and Preparing local spatial Municipalities Jemgum and
Oldambt development plans Bunde
Final Report Climate (Ex)Change - Normative Tide
Annex V: Glossary
Besides explanations or descriptions this glossary provides translations of terms that might be confusing or unknown. The format of the list is illustrated in the following example:
Word in report Description or definition of the term. Dutch translation; German translation
Climate change The change of climate which is attributed directly or indirectly to Klimaatverandering; Klimawandel human activity that alters the composition of the global atmosphere and which is in addition to natural climate variability observed over comparable time periods.
Climate scenario Scenarios defined in order to compare different possible changes Klimaat scenario in climate.
Competent authority The authority with relevant powers and responsibilities Bevoegd gezag; Zuständige Behörde
Culvert A tube connection waterways, often located in access roads, dams Duiker; Durchlass or dykes
Dyke ring System of primary flood defence structures that provide protection Dijkring against flooding
Dyke ring area An area that is protected against flood by a system of flood Dijkring gebied protection structures
Flood The temporary covering by water of land not normally covered by Overstroming; Hochwasser water.
Flood protection All (necessary) measures and policies needed for the prevention Hoogwaterbescherming; and/or reducing the effects of flood events, which can cause Hochwasserschutz adverse effect on human beings, their property and nature.
Flood defence zone Area of 100 m on both sides of a dyke reserved for future Waterkeringszone adaptations.
Flood risk management plan Plans including measures for achieving the objectives for the Overstromingsrisicobeheerplan; management of flood risks. Hochwasserrisikomanagementplan
Flood risk map Maps showing the potential adverse consequences associated with Overstromingsrisicokaart; flood scenarios. Hochwasserrisikokarte
Flotsam (Organic) material that floats in the sea and eventually washes Zeedrift;Treibgut ashore.
Annexes
Flow slide The phenomenon where saturated sand behaves as a fluid with the Zettingsvloeiing result the loss of grain tension.
Halophilous plants Plants that thrive in a salty environment. Zoutminnende planten; Salz liebende Pflanzen
Hazard map Maps covering geographical areas which could be flooded. Overstromingsgevaarkaart; Hochwassergefahrenkarte
Hydraulic preconditions Preconditions defined to audit dykes. Hydraulische randvoorwaarden
Nature conservation Efforts to preserve, restore and develop natural resources. Natuurbescherming; Naturschutz
Primary flood defence Structures providing safety against flooding by being included in a structure dyke ring or located in front of a dyke ring. Primaire waterkering
Review level Water level corresponding with a probability of exceeding defined Toetspeil in the standards.
River basin The area of land from which all surface run-off flows through a Stroomgebied; Fluß einzugsgebiet sequence of streams, rivers and, possibly, lakes into the sea at a single river mouth, estuary or delta.
Safety region A defined region in the Netherlands in which governmental bodies Veiligheidsregio and emergency services cooperate in case of a disaster.
Salt marsh Low coastal area on the sea side of a dike which is formed due to Kwelder; Salzwiese land accretion.
Section of free space A zone of 100 m on each side of a dyke reserved for future Profiel van vrije ruimte adaptations to the dyke.
Specification for safety audit Specifications for auditing primary flood defence structures Voorschrift Toetsen op Veiligheid
Storm oscillation Short term variation in water level with changing periods due to Bui oscillatie heavy rainfall or storm.
Wake height Difference between the construction height of a dyke and the Waakhoogte review level.
Water Assessment Process An assessment performed by the Dutch water authorities to check Watertoets spatial development plans on water related issues.
Wind gust Short term variation in water level with changing wave period due Buistoot to sudden and brief increase of wind speed.
Final Report Climate (Ex)Change - Normative Tide