WFD 2027: Fish habitat restoration along the Zwarte Water through riverbank optimization

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WFD 2027: Fish habitat restoration along

the Zwarte Water through riverbank optimization

Claudia Schwennen

June 2020

Student number: 10655808 Course: Internship Earth Sciences (24 EC)

Daily supervisors: Drs. M. Pfaff-Wagenaar & D. Den Houting (MSc) Examiner: Dr. H. G. Van der Geest

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1. Summary of the internship

Due to human intervention in lowland rivers, for example through the normalisation of the river, natural dynamics have been significantly altered, which has resulted in a considerable biodiversity loss in lowland rivers. In addition, the water quality has deteriorated as a result of industrialisation and the increase of the population density. As a response, the EU Water Framework Directive 2000/60/EC (WFD) was introduced in 2000 and marked a new approach in water management in which an internationalized, integrated and holistic framework was adopted in order to protect European water bodies. This gives Member States the responsibility of reaching a good ecological status of their water bodies by 2027, which is also the case for the Netherlands. A WFD strategy plan was developed at Lievense, commissioned by Rijkswaterstaat (Directorate-General for Public Works and Water Management), which involves the construction of 900 m side channel and riverbank optimizations along a length of 8.3 km. During the internship period, the focus was on restoring nursery and spawning areas along the riverbanks of the main channel by creating low flow zones for limnophilic fish species. These zones require a rehabilitation structure to protect the aquatic biota from passing shipping vessels. Through a literature review, a multi-criteria analysis was performed to assess different options for the rehabilitation structure and through a GIS-analysis, suitable locations were selected where optimization could be performed. In addition, suitable locations for the connection of backwaters were also explored. Subsequently, the strategy plan was developed and the outcomes of the analyses were adopted within this plan, resulting in the Policy Vision. In addition, the ecological requirements of the low flow zone were studied through a literature review, which serves as a basis for the design phase of the project. Finally, a stakeholder analysis was performed in order to ensure that the strategy plan can be implemented successfully. The internship was very successful and educational. It has provided the experience of working on environmental issues with other specialists in a professional setting, which is needed for the Environmental Management track of the master programme.

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2. Description of the company and type of activities

The internship took place at Lievense | WSP, a multidisciplinary consultancy and engineering firm. They operate in the areas of infrastructure, buildings, water and the environment. There are about 375 employees, which makes it one of the larger consultancy firms in the Netherlands and their offices are visualized in figure 1. Recently, Lievense was acquired by WSP, a Canadian consultancy firm operating globally (figure 2). The department I worked at is the Water & Environment department. Within the water and environment areas, Lievense is involved in the design and decision-making processes of numerous projects. They also conduct studies within the field of environmental and civil engineering and urban development. Finally, they also facilitate the collaboration between partners within relevant fields, such as shipping, spatial quality, flood risk management and development of the natural environment.

The annual plan of this department states that further development is expected within the fields of the waterworks, integrated river management, water quality and WFD projects, water management in relationship to climate

adaptation and sea level rise. In addition, Lievense strives to respond to the trends that are happening at the ‘landscape’ level. Trends that have been identified are as follows:

• Mandatory participation (involvement of stakeholders) due to the implementation of the Environment and Planning Act (Dutch translation: omgevingswet)

• Larger projects that use a more integrated approach • Customers’ wishes for innovation and continuity • Sustainability and circularity

• Energy transition

• Automatization and digitalization • Scarcity of professionals

Response to trends is also facilitated through the Future Ready programme by WSP. This is a global innovation programme that aims to provide solutions and advices for future realities and identifies this through trends happening in the fields of climate change, technology, resources and society.

Figure 1. Lievense offices in the Netherlands (Lievense, n.d.)

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3. Internship report

3.1 Introduction

Over the past centuries the human impact on river systems has heavily altered fluvial dynamics and the course of the rivers with the goal of ensuring navigation, agriculture and the protection of the hinterland (Grift, 2001). This was done through the use of dams and reservoirs in headwaters, but also through channelization and floodplain reclamation in lowland rivers (Buijse et al., 2002). Moreover, industrialization and the increase of the population density in the river basin has resulted in a considerable decrease of the water quality (Grift, 2001). As natural dynamics have disappeared, aquatic species have reduced in numbers, thereby affecting the overall biodiversity (Grift, 2001; Buijse et al., 2002). This has caused riverine floodplains to be one of the most endangered landscapes globally, which is partly caused by the reduction of transition zones from aquatic to terrestrial ecosystems (Buijse et al., 2002). As a response to these growing concerns, the EU Water Framework Directive 2000/60/EC (WFD) was introduced in 2000 and marked a new approach in water management in which an internationalized, integrated and holistic framework was adopted in order to protect European water bodies (Van Leussen & Meijerink, 2014; Voulvoulis, Arpon, & Giakoumis, 2017; European Commission, n.d.). The aim of the WFD is for Member States to reach the environmental objectives and a “good status” of their water bodies by the end of the third management cycle in 2027 (Voulvoulis, Arpon, & Giakoumis, 2017).

The Dutch government also has the obligation to meet these environmental objectives for the national waters, which includes the Zwarte Water. This river originates from a confluence of the Sallandse weteringen or streams and is connected to the IJssel river and to the Overijsselse Vecht, which originates from Western Germany (Altenburg, Bronger & Van der Heide, 1990). Because of its connection to the IJssel, commercial shipping plays an important role in this system. The main objective of the WFD project in the Zwarte Water is to improve habitat conditions, including nursery and spawning areas, for fish. This requires an integrated approach to ensure that the WFD goals are met, while taking other aspects into consideration as well, including the Natura 2000 goals, recreation, river dynamics, shipping and sustainability. Rijkswaterstaat (Directorate-General for Public Works and Water Management) has requested Lievense to work on this project that involves the construction of a 900 m secondary channel and the optimization of riverbanks along a length of 8.3 km. After discussions, it was decided that the connection of backwaters can also be implemented. These strategies are part of the Dutch multi-year programme for

infrastructure, spatial planning and transport (MIRT, Meerjarenprogramma

Infrastructuur Ruimte en Transport). The

project entered the 3rd_{phase of the MIRT}

process flow in January 2020 and is expected to be finalized in September 2020, after which the final phase can be

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3.2 Internship assignment

In order to reach a “good status” of the water bodies, the Dutch water bodies are assessed using an ecological indicator called the Ecologische Kwaliteit Ratio’s (EKR) or the Ecological Quality Ratio (Van Keeken, 2019). This is done by comparing the concerning waterbody with similar waterbodies that have had no or negligible human influences (ibid.) Factsheets of the Zwarte Water show that the EKR is inadequate with regard to fish species (WDOD, 2015a), which can be attributed to the lack of transition zones between terrestrial and aquatic ecosystems and the lack of migration facilities to floodplains, as explained in the introduction. The main channel, which is used for navigation, does not create the desired conditions for primary production that are necessary for aquatic organisms due to the large water depth and the high flow rate (Grift, 2001). In addition, the riverbanks are relatively steep and hydraulic dynamics caused by shipping vessels are inhibiting the growth of aquatic and littoral vegetation (Weber, 2016; Sukhodolova et al., 2017) and are harmful for small size fish species, especially during the first life stages (Wolter et al., 2004). This has therefore resulted in a lack of suitable habitats for fish species (Francis et al., 2008). As such, the desire is to improve the riverbanks along the main channel. Rijkswaterstaat has set several target species that are representative for the desired habitat types and include limnophilic fish species that require low flowing waters (Grift, 2001). Subsequently, the aim is to create low flow zones along the riverbanks that are protected from the hydraulic dynamics through technical protection structures or rehabilitation structures. Furthermore, the project also involves the construction of a secondary channel, but this is not elaborated upon within this report, as extensive plans had been developed for this construction already. Finally, another strategy includes the connection of backwaters. These objectives align with the objectives of the Natura 2000, as the area is part of the Natura 2000 area Uiterwaarden Zwarte Water en Vecht, partly due to the presence of one of the largest populations of the snake’s head fritillary (Fritillaria meleagris) (Runhaar, Raterman, & Zaadnoordijk, 2014). Habitat types and species, including some target species, that are listed in the Habitats Directive, as well as in the Birds Directive, require the designation of special areas of conservation and are therefore assigned protective areas (Grift, Buijse & Van Geest, 2006).

Figure 5. Natura 2000 area (adapted from Ministry of Agriculture, Nature

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During the internship period, as visualized in table 1, a variety of tasks need to be completed in order to reach the objective. During the first half of 2020, several milestones need to be reached, including the establishment of the Scope for 2022, a Policy Vision (Dutch translation: inrichtingsbeeld) and design proposals on the riverbank optimization and on the final design of the secondary channel. The activities to reach these milestones include:

• Expert meetings • Literature review

• Multi-criteria analysis of different riverbank optimization methods • GIS analysis of location suitability

• Stakeholder analysis

3.3 Study area

3.3.1 Geological development

During the start of the Pleistocene, sand was deposited in the study area through the Rhine river and other rivers in the East, including the Elbe, Ems and Weser. Following this, the Netherlands was covered with glaciers during different phases of the Saale glaciation. During one of these phases, the glacier front reached the northern part of the study area causing a change in stream direction from north to west during which the primordial stream valley was formed. In the following time periods, this valley was filled with sand and clay depositions, followed by peat and finally by cover sand. As the climate became warmer during the Holocene, precipitation increased and the sea level rose. These favourable conditions in turn stimulated peat formation. In addition, the sea level rise also caused the study area to be flooded regularly and resulted in marine clay deposition, which can be found in the Northern part of the study area. Fluvial clay depositions can be found southwards of Hasselt. Nowadays, sedimentation processes within the river are essentially absent due to human interventions, which include dike constructions and substantial river management (Altenburg, Bronger & Van der Heide, 1990).

Table 1. Time schedule of the internship

Month Milestones Activities

March

• Expert meetings with topics including: • Risk analysis and decision making • Riverbank optimization measures • Connection of backwaters • Riverbank reconstruction design • Literature review

• Multi-criteria analysis • GIS analysis

Interim assessment at start of May

April

May

• Literature review • Stakeholder analysis

• Research and 2 meetings regarding the design of the secondary channel, riverbanks and connections

Finalizing internship report

June

15/05

Determine scope of WFD 2022, locations of riverbank

optimization and first draft of the Policy Vision

10/07

Design Proposal on riverbank optimization methods and the secondary channel

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3.3.2 Site description

The Zwarte Water is a 19 km low flowing river (Koorneef, 2015) that runs through a peat landscape (Provincie Overijssel, 2017a; Provincie Overijssel, 2017b). This landscape consists of estuaries, formed from tidal depositions, point bars with dykes and sand ridges with small lakes, which for the most part is connected to the river. The riverbanks along the Zwarte Water mainly consist of soils with a top layer of non-calcareous clay and underneath this peat, clay or sand can be found. Floodplains and riverbanks are relatively small in width. The floodplains consist of secondary channels, kolks (vortex), river dunes and copse woodlands. The vegetation along the riverbanks consists of reed and brushwood. Wetlands can also be found along the lower parts over the riverbanks. Through the Zwarte Meer, the river is directly connected to the IJsselmeer (ibid.).

The water level varies considerably and is highly influenced by a combination of the water level in the IJsselmeer, the drainage of the river and by wind dynamics (Koorneeg, 2015; Provincie Overijssel, 2017a; Provincie Overijssel, 2017b). When drainage is low, water levels are mainly determined by the water level in the IJsselmeer (ibid.). After a new type of water level management had been implemented in the IJsselmeer, which allows for more flexible management, the target water level of the IJsselmeer varies between -0.10 m NAP (Amsterdam Ordnance Datum) and -0.30 NAP in summer and between -0.20 m NAP and -0.40 m NAP in winter (Rijkswaterstaat, 2018). At the Zwarte Water the water level varies between -0.20 m NAP and +0.50 m NAP throughout the year (Provincie Overijssel, 2017a; Provincie Overijssel, 2017b). High water levels are mainly caused by peaks in precipitation and by the westerly winds that may result in surges in the IJsselmeer, although the frequency of strong westerly winds have been less prominent since 2003 compared to the period before and it is uncertain whether this can be attributed to incidental meteorological circumstances or to climate change (Runhaar, 2018). However, high water levels can be controlled by the inflatable dam located at Ramspol (Runhaar, Raterman, & Zaadnoordijk, 2014), which is closed at water levels that exceed +0.50 m NAP (Van Duin et al., 2017). Before the Zuiderzee was disconnected from the sea, water level dynamics were much stronger in the Zwarte Water (ibid.). In addition, these dynamics have also been strongly altered by the construction of the Noordoostpolder and by the way river management was conducted (Provincie Overijssel, 2017a; Provincie Overijssel, 2017b).

Though agricultural activities nearby also affect to the water quality in the river, the water quality is mainly determined by activities that occur outside of the Natura 2000 area. Due to levels of nitrogen and phosphate, the river can be classified as eutrophic, although the levels have significantly decreased in the past. Despite this, these levels still exceed target levels (Provincie Overijssel, 2017a; Provincie Overijssel, 2017b).

3.4 Restoration vision

As explained earlier, the Zwarte Water is lacking the natural dynamics that result in morphological and hydrological complexity, which are all needed to support the biodiversity (Grift, 2001; Buijse et al., 2002; Weber, 2016). The lack of morphological complexity can be seen in the deepened, straightened and stabilized riverbanks that resulted in direct habitat loss, while the lack of hydrological complexity can be seen in the altered and stabilized inundation regime, which has also affected the biodiversity (Weber, 2016). As the socioecological aspects of the river have become strongly integrated into the system, it seems

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unlikely that it can completely return to the natural state (Wolter, 2001). Certain areas have been enclosed by dykes in which conflicting land use is performed, including agricultural activities, thereby eliminating the possibility of restoring inundation regimes (Runhaar, 2018). Furthermore, some of these enclosures are irreversible, as subsidence in the area has occurred and this would lead to permanent inundation of the area (ibid.). However, efforts in conservation and rehabilitation strategies within navigable waterways have still proven to be highly effective in improving biodiversity (Wolter, 2001). Besides the construction of the side channel and increasing the migration facilities to adjacent floodplains, the reconstruction of riverbanks has also been proposed as an effective method in literature (ibid.).

Eco-friendly riverbanks have been widely applied within the WFD in the Netherlands (De la Haye et al., 2011). These are riverbanks with a gradual slope that provide the transition zone from terrestrial ecosystems to aquatic ecosystems that is needed to support the biodiversity (Vuister, 2010). However, these cannot be realised in the area without technical protection structures, as hydraulic dynamics caused by the passing shipping vessels negatively affect aquatic biota (Wolter et al., 2004; Weber, Garcia & Wolter, 2017). Furthermore, together with these structures a zone of low flow can be created along the riverbanks, which is needed for the target species (Grift, 2001) and this will also stimulate the growth of littoral vegetation that is needed to create suitable habitats (Van Kouwen et al., 2011; Pohnke & Klinge, 2018). However, the area also provides other functions and inhibits different users. Therefore, it is necessary to keep these into account when realising the proposed strategies. A very important component of this system is the shipping sector and navigation safety must be ensured. Water safety is another factor that must be ensured, as the Zwarte Water is part of the Beleidslijn

Grote Rivieren, which aims to secure flood protection and to ensure the possibility of river

expansion (Ministry of Infrastructure and Water Management, 2006). This also means that the proposed strategies cannot affect the protection zones of the dykes as assigned by the waterboards. Moreover, the area is also used for fishing purposes, both commercial and recreational, which plays an important role in the fish stock as well. In addition, the Natura 2000 goals offer possibilities of creating synergy, but it may also be a limitation for the realisation of the proposed strategies if these strategies form a risk for the Natura 2000 goals, for example in areas that inhibit the snake’s head fritillary. Lastly, property owners play an important role in the realization of the project. These owners include different governmental institutions, nature organisations and private owners.

3.5 Multi-criteria analysis of riverbank optimization methods

In order to successfully create eco-friendly riverbanks along the main channel of the river, these riverbanks require a rehabilitation structure to protect them from the hydraulic dynamics caused by shipping vessels. There is a great variety of solutions that can be used and discussions between Lievense and Rijkswaterstaat have resulted in 8 solutions that were assessed through a literature review of available scientific literature and reference projects using a multi-criteria analysis. These are visualized in Appendix 1. They include 6 vertical rehabilitation structures, a green floating structure and an unprotected, eco-friendly riverbank: • Wooden paling • Embankment of quarry rocks

• Wooden paling with bundle of twigs • Embankment of gabions • Timber sheet pile wall • Green floating structures • Steel sheet pile wall • Eco-friendly riverbanks

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3.5.1 Criteria

The assessment criteria were identified during the discussions as well. The deterministic criteria include (1) the ecological effectiveness, (2) feasibility, (3) use of space and (4) management and maintenance. In addition, sustainability and costs were identified as well, but were not used as deterministic criteria. The scoring scheme can be seen in the following table. The following sections give further explanations to these criteria and the scoring.

Table 2. Scoring scheme

Negative Neutral Positive Very positive

3.5.1.1 Ecological effectiveness

In order to reach the WFD objectives, the measures taken need to improve the environmental conditions in the Zwarte Water to subsequently create suitable habitats for the target species. As explained before, habitats for these species are currently missing due to the large water depths of the riverbanks and the water dynamics caused by shipping. These target species need areas with low flow, which also would stimulate the growth of aquatic and littoral vegetation that is needed for suitable habitats of these species (Van Kouwen et al., 2011). Therefore, the aim of the proposed solutions is to create these zones by shielding them from the water dynamics and to create a low turbidity to ensure optimal light conditions, which is also needed to stimulate vegetation growth (Grift, 2001). In addition to the creation of low flow zones, a higher structure complexity of the structures may sustain a variety of species and create complex ecological communities, thereby contributing to the biodiversity (Francis et al., 2008). This means that structures with rough surfaces are favoured over structures with flat surfaces. Finally, the choice of materials used in the rehabilitation structure may contribute to the ecological effectiveness by using materials that can be found locally in the area (Van Kouwen et al., 2011).

Table 3. Scoring explanation ecological effectiveness

Score Explanation

Positive Construction type protects area from water dynamics and turbidity.

Neutral Construction type moderately protects area from water dynamics and turbidity. Negative Construction type does not protect area from water dynamics and turbidity.

3.5.1.2 Feasibility

The feasibility of the rehabilitation structure essentially means whether the construction can be completed within the adopted timeframe. This depends on whether it is possible to work with certain materials within the available dimensions and whether the production and construction are labour intensive. This in turn depends on the water depth at which the construction type needs to be constructed and on the working methods (Boeters & Van den Burg, 1997). Additionally, due to the large water depths at the riverbanks, earthmoving will likely be needed in order to facilitate the development of aquatic and littoral vegetation. Therefore, the rehabilitation structure needs to be secured in order to prevent sediment loss, which makes the construction more labour intensive. Moreover, other factors that may affect the completion have been identified during discussions between Lievense and Rijkswaterstaat.

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These include permit procedures and the landownership. Naturally, properties that are owned by Rijkswaterstaat and that do not require permits would make the construction more feasible within the adopted timeframe.

Table 4. Scoring explanation feasibility

Score Explanation

Positive Applicable in all situation and no obstacles associated with permits and landownership.

Neutral Applicable in limited situations and possible obstacles associated with permits and landownership.

Negative Difficult to achieve and obstacles associated with permits and landownership.

3.5.1.3 Use of space

Depending on the characteristics of the location, different rehabilitation structures may be chosen that will differ in the required use of space. The assessment is based on the relative amount of space that constructions use within the cross-section of the river. Therefore, at certain locations where the amount of available space is limited, certain construction types need to be excluded.

Table 5. Scoring explanation use of space

Score Explanation

Positive Construction relatively needs a little amount of space. Neutral Construction relatively needs a moderate amount of space. Negative Construction relatively needs a large amount of space.

3.5.1.4 Management and maintenance

Management and maintenance are needed to ensure that the rehabilitation structure keeps functioning successfully, but this varies per rehabilitation structures type (Van Kouwen et al., 2011). Management and maintenance can be distinguished by the following categories:

• Vegetation; to control the composition of vegetation in the area and to prevent encroachment (ibid.).

• Constructional damage; this may result from water dynamics, root activity, fallen trees, drift ice, subsidence, the decomposition of materials and vandalism (ibid.).

• Erosion and sedimentation; although occurring in normal conditions as well, during high water levels erosion may become substantial. In addition, sedimentation can be caused by low flows and the presence of structures and vegetation in which the sediment may be caught (ibid.).

These factors determine the frequency and the intensity of the management and maintenance. Management of vegetation is very dependent on the desired composition of the vegetation, while constructional damage is dependent on the choice of construction- and material type. The choice of location and the design of the rehabilitation structures will greatly determine erosion and sedimentation processes (ibid.).

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11 Table 6. Scoring explanation management and maintenance

Score Explanation

Positive Management and maintenance intensity is limited (due to low degree of constructional damage) and needs to be performed at a low frequency. Neutral Management and maintenance intensity is moderate (due to moderate degree of constructional damage) and needs to be performed at a higher frequency.

Negative Management and maintenance intensity is high (due to high degree of constructional damage) and needs to be performed at a high frequency.

3.5.1.5 Sustainability

Rijkswaterstaat has set sustainability goals for MIRT projects and therefore it is crucial to assess how this can be used during this project. Their goals include a reduction of 50% in the use of primary raw materials and a reduction of 95% in CO2_{emissions by 2050. In addition, by 2030}

circularity should completely be implemented within the working method at Rijkswaterstaat, meaning that materials will be reused as much as possible and waste production will be minimized. Through these goals, Rijkswaterstaat hopes to minimize the environmental impact (Rijkswaterstaat, 2019).

Within this project, sustainability can be approached through different aspects. Van Dam & Van den Oever (2012) assessed how sustainability is applied within construction works. Within this sector a lot of attention is given to the reduction of energy use and to the re-use of raw materials. Moreover, the environmental impact can be assessed through aspects, such as SO2

and ethene production (ibid.). Aspects such as these may be used in Life Cycle Assessments (LCA’s) (Glover, White & Langrish, 2002). For example, these LCA’s indicate that steel has a very poor score in comparison with other materials (Van Dam & Van den Oever, 2012). However, this score can be significantly improved when using the cradle to cradle perspective, rather than the cradle to grave perspective (ibid.).

In addition to this, the Environmental Cost Indicator (ECI) can be used to assess the environmental costs of constructions as well, which is expressed in euros, where low values would indicate a better performance (Rijkswaterstaat, 2013). Reviews of this indicator for different materials also show that re-use can have a very positive impact on the ECI values (Ecochain, n.d.).

3.5.1.6 Costs

Ruijgrok et al. (2011) identified factors that determine the costs for different riverbank and rehabilitation structure types and distinguished this through design costs, construction costs and maintenance costs. Factors determining the design and construction costs are (1) costs for the removal of old structures, (2) costs for earthworks, (3) material costs, including during installation, and (4) indirect costs, such as administrative and staff costs. Factors that determine the maintenance costs include management of vegetation, maintenance of structures and maintenance that is needed due to erosion and sedimentation, as described earlier.

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3.5.2 Final assessment

Using the described assessment criteria, the following table shows the overview of the assessment. Because of feasibility issues associated with the paling constructions and because of high maintenance, these are not considered further. At locations where there is sufficient space availability and where hydraulic dynamics are considered too strong, embankments of quarry rocks may be used (Rijkswaterstaat, 2002). Embankments of gabions are also not considered further, due to feasibility issues. At locations where there is insufficient space availability, vertical constructions can be used. However, there are some constructional restrictions due to the water depth. At depths larger than 2.5 m, sheet pile walls made of steel are required. Finally, at locations where it is not possible to reduce the water depth (through earthmoving), green floating structures may be used (Didderen & Paalvalst, 2015). However, studies show that there are requirements for the construction in order to reach ecological effectiveness. If these requirements are not met, it may not produce the desired results (ibid.). Due to the shipping activity in the main channel of the river and the associated hydraulic dynamics, unprotected, eco-friendly riverbanks will likely not produce the desired results. However, they may still be realised on land by creating low flow zones behind current riverbanks that will be maintained.

Table 7. Summary of the analysis for the reviewed construction types

Construction types Ecological effectiveness Feasibility Use of space Management and maintenance Wooden paling

Wooden paling with bundle of twigs

Timber sheet pile wall Steel sheet pile wall Embankment of quarry rocks Embankment of gabions Green floating structures Eco-friendly riverbanks

3.6 GIS analysis of location suitability

In collaboration with the GIS specialist at Lievense, a GIS analysis was performed using ArcGIS in order to identify the suitable locations for riverbank optimization methods. The result also offered an indication of the possibility of reaching the 8.3 km requirement for the WFD goals. The suitability of the location was based on the area functions as described in section 3.4, which were translated into preconditions or criteria that were verified through discussions between Lievense and Rijkswaterstaat. These are listed in the table 8. In addition to this, exclusions were identified as well and are listed in table 9. The output consists of locations that are suitable for measures in the river, measures on land and locations where both options are possible.

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13 Table 8. Preconditions for the GIS analysis

Input Setting Comments

Bankline At -0.20 m NAP Median water level

Shipping channel Outer edge Minimum width

riverbank zone within RWS plots

10 m

Minimum distance bankline to the shipping channel

14 m Minimum of 10 m for the ecological effectiveness and minimum of 4 m for the distance between the construction and the shipping channel due to safety reasons.

Minimum width major bed

None Water storage within this zone may not decrease with more than 5%.

Minimum width minor bed

100 m Measure may not intersect summer dykes.

Table 9. Site exclusions for riverbank optimization

Input Setting Comments

Fishing spots No measures Quaysides No measures Cables and pipes No measures Trees No land measures

Dyke zones No land measures in protection zones as identified by the waterboards.

No excavations in this zone due to issues with piping and constructions need to be assessed by the waterboards.

The bank line was set at -0.20 m NAP, while the outer edge was used for the shipping channel, as there are several edges identified within this layer. For the minimum width of the plots owned by Rijkswaterstaat and for the minimum distance to the shipping channel, buffers were created and set at 10 m and 14 m as a criterium within the model. This means that plots owned by for example the National State Forestry Agency are not considered within this analysis. There was no criterium set for the minimum width of the major bed, as it was assumed that the water holding capacity would not be not altered after the rehabilitation structures would be placed. However, this assumption does not hold for the minor bed and therefore the minimum width was set at 100 m. Moreover, the exclusions include locations where fishing spots, quaysides, cables and pipes are present. Measures on land are excluded in locations where trees are present and where the waterboards have identified the protection zone along the dykes, due to risks of piping within this zone.

These criteria were set within the field calculator function in ArcGIS using Python to produce the suitable riverbanks along the bank line. This resulted in the map in figure 6 where suitable locations were identified for measures in the river, on land and where both options are possible. It also shows that the total length of suitable riverbanks is well above the 8.3 km requirement for the WFD goals, which allowed for further selection.

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3.7 Proposed strategies

The analysis of the rehabilitation structures and the locations have resulted in the proposed strategies as described in the Policy Vision, which is summarized in figure 7. It also includes a few locations that have been identified during expert meetings and where backwaters can be connected to the river. As I was not greatly involved in the assessment and selection process of the backwaters, this is not elaborated further upon. The lengths of the proposed strategies add up to a total length of 18.9 km, which is well above the 8.3 km requirement.

Further selection of the suitable locations was based on the water depth and the length at which measures could be realized. This resulted in the exclusions of locations where the water level was too deep and where the length was less than 50 m. The selected rehabilitation structure is visualized at the suitable locations that were identified in the GIS analysis. As explained in the previous section, locations were identified where riverbank optimization could be carried out in the river, on land or where both options are possible. In the last case, the

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choice between land or water was based on creating uniformity and on maintaining navigation safety with the goal of creating the longest possible stretches with either land or water measures. The choice was also based on the constructional restrictions for the different methods. Based on Life Cycle Assessments (Van Dam & Van den Oever, 2012), timber sheet pile walls have a significantly better score than other materials, such as quarry rocks or steel, so these are implemented wherever possible. However, due to their standard dimensions and the constructional requirements (Houtwijzer GGW, 2017), steel sheet pile walls are chosen instead at locations where the water depth exceeds 2.5 m. In addition, embankments of quarry rocks are implemented where the available space between the riverbank and the shipping channel is at least 5 m. Moreover, a few locations have been identified during expert meetings where eco-friendly riverbanks are present and are protected by existing embankments of quarry rocks that require adaptation. Therefore, these have also been adopted in the proposed strategies.

Figure 7. Proposed strategies; including the selected optimization method at the suitable locations, as well as the selected backwaters (Lievense, 2020)

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3.8 Establishment of the transition zone behind the construction

The aim of the before mentioned strategies is to create a more natural gradient in the transition zone between terrestrial and aquatic ecosystems that is protected from hydraulic dynamics in order to create low flow conditions, which are required for the development of the littoral vegetation and the limnophilic target species (Van Kouwen et al., 2011). Additional benefits from these zones is that they can contribute to the Natura 2000 goals, by improving the environmental conditions for certain water bird species and reed marshes (Liefveld et al., 2008). The quality of the potential habitats is dependent on factors such as accessibility, vegetation density and light circumstances (Pohnke & Klinge, 2018). For the establishment of the transition zones it is important to recognize that the creation of variation in environmental conditions, which also exists in the natural state (Liefveld et al., 2008; Van Kouwen et al., 2011), can be highly beneficial for the overall biodiversity and the resilience of the ecosystem, while also preventing the establishment of invasive species (Weber, 2016).

3.8.1 Vegetation

Plantation seems to be unnecessary as seeds from upstream areas may easily establish within the transition zone (Weber, Lautenbach & Wolter, 2012) and research shows that naturally vegetated areas have better ecological indicator scores as opposed to areas that have been artificially planted (De la Haye et al., 2011). Though studies show that the number of fish species associated with aquatic plants can already substantially increase at a plant coverage of approximately 10% (Pohnke & Klinge, 2018), other studies have shown that the protected zone may quickly become too densely vegetated, which eventually could decrease the habitat suitability (Weber, 2016; Sukhodolova et al., 2017). This is a result of the decreased hydraulic dynamics, as the dense vegetation further inhibits the influx of water originating from the main channel ultimately resulting in decreased oxygen levels within this zone due to a combination of increased community respiration and a lack of water exchange (ibid.). Furthermore, this may also limit the accessibility of the area for fish species (Pohnke & Klinge, 2018) and increase the risk of algal blooms, mosquito plagues and excessive sedimentation (Van Kouwen et al., 2011). This demonstrates the importance of finding a balance between the hydraulic dynamics and the creation of a low flow zone (Van Kouwen et al., 2011). Additional maintenance and management will be required to prevent the vegetation of becoming too dense (De la Haye et al., 2011). However, there are a number of solutions to deal with these risks during the designing phase, for example by creating openings in the rehabilitation structure or through gradual removal of the rehabilitation structure (Weber & Wolter, 2017; Sukhodolova et al., 2017).

Specific vegetation types, including helophytes and specifically reed marshes, are important parts of the target species’ habitats during winter and should therefore be in the proximity of aquatic vegetation, so that migration can be facilitated between different areas during different seasons (Pohnke & Klinge, 2018). However, fluctuating water levels and temporary drought is necessary for effective development and vitality of these vegetation types (De la Haye et al., 2011; Pohnke & Klinge, 2018). This means that in order to support these vegetation types, the riverbank must be designed in a way that allows for temporary drought conditions and as the Zwarte Water deals with considerable water level variation, this may be considered when determining the water depth of the riverbank.

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3.8.2 Rehabilitation structure

The rehabilitation structure is required to diminish the hydraulic dynamics (Wolter et al., 2004; Van Kouwen et al., 2011). This can be done by determining the height and the orientation of the structure and by determining the distance between the riverbank and the structure (Van Kouwen et al., 2011). The Zwarte Water harbours intensive shipping activities and deals with considerable variation in water levels (Koorneef, 2015), due to the hydrological processes occurring here, as explained in the site description. Rivers with increased hydraulic dynamics as a result of high shipping activity and increased wind dynamics require a higher structure compared to rivers that do not have increased hydraulic dynamics (Van Kouwen et al., 2011). Moreover, rivers with more frequent occurrences of increased water levels also require higher structures (Van Kouwen et al., 2011). Though Liefveld et al. (2008) mention that a height at or just below the prevailing water level may be sufficient to diminish the impact of the hydraulic dynamics and simultaneously may have a more positive effect on the landscape aesthetics. However, it is important to adjust the height according to the water level during spring, as this is the most critical period for the establishment of the vegetation (ibid.). To deal with wind dynamics, the orientation of the rehabilitation structure may be adjusted to a bow shape rather than a straight line where riverbanks are parallel to the prevailing wind directions (Van Kouwen et al., 2011). Finally, the distance between the riverbank and the structure can be decreased, though in this project the distance will be approximately 10 m and this would be sufficient to deal with wind dynamics (ibid.).

Section 3.8.1 has demonstrated that water exchange between the low flow zone and the main channel must be ensured. In order to deal with the risks associated with decreased hydraulic dynamics, the rehabilitation structure can be designed accordingly by creating openings in the rehabilitation structure (Van Kouwen et al., 2011). The openings create an additional benefit by ensuring that animals that have fallen into the river are no longer prevented from exiting the river due to steep riverbanks acting as barriers, though collaboration with other stakeholders should ensure that barriers on land are also removed (Wansink, Van Gogh & Wielakker, 2016). Similar strategies performed in the IJssel river used openings of approximately 1 m for every 10 m of the rehabilitation structure in order to maintain water exchange and to facilitate accessibility (Willems & Van Winden, 2011), which has also been documented in other studies (Weber & Wolter, 2017; Weber, Garcia & Wolter, 2017). However, this may be more suitable for waters with higher flow rates where rheophilic species may be more common (Wolter, 2010). Due to suction and return of currents as a result of passing shipping vessels in the Zwarte Water, it is expected that openings with that frequency will not decrease hydraulic dynamics to a sufficient level for limnophilic species. This may be dealt with by placing additional protective structures perpendicular or parallel by the openings (Sukhodovola et al., 2017). Another possibility that has been documented in the literature is creating openings at distances of approximately 50 m (Weber & Wolter, 2017; Weber, Garcia & Wolter, 2017), which is also the recommended maximum distance for exit locations for small animals that have fallen into the river (CUR, 1994).

As mentioned earlier, a higher structure complexity of the rehabilitation structure may sustain more complex communities and therefore contribute to fish abundance and the overall biodiversity (Francis et al., 2008; Weber, 2016). The design of the rehabilitation structure may also contribute to this by applying a coating with a more complex structure onto the sheet pile walls, which also creates a more positive effect on the landscape aesthetics.

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3.8.3 Riverbank

The transition zone behind the protective constructions requires the addition of soil in order to create lower water depths that are needed for the establishment of aquatic and littoral vegetation (Van Kouwen et al., 2011), as well as for the target species (Pohnke & Klinge, 2018). As the habitat requirements of these target species differ among them, the required water depth may vary between 0.3 and 2 m during the average water level (Van Emmerik & De Nie, 2006; Van Kouwen et al., 2011). In addition, both for the presence of different fish species and for the establishment of the vegetation, the soil type and granular size are determining factors and creating variation is also in this case important in order to sustain different fish species during different life stages (Van Emmerik & Quak, 2020), which ultimately may stimulate the biodiversity. However, it will be unfeasible to reach this and therefore soil addition will be enabled using the soil that will be made available during the construction of the side channel and it will be enabled through an external project that involves sand extraction. Generally, soils containing nutrient poor sand are associated with more complex communities as opposed to soils containing nutrient rich clay or peat (De la Haye et al., 2011). Sand addition may be done at the start and the end of the rehabilitation structure where there is in- and outflow of water in order to provide suitable spawning substrate for rheophilic fish species (Van Emmerik & Quak, 2020).

To maximize the surface area of shallow waters during fluctuating water levels, the transition zone requires a gentle slope of at least 10%, but preferably lower to approximately 3% (Liefveld et al., 2008, Vuister, 2010; Van Kouwen et al., 2011). Riverbanks with gentle slopes have also shown better ecological indicator scores as opposed to riverbanks with steep slopes (De la Haye et al., 2011). Monotonous riverbank profiles have been an important reason for habitat homogenization and loss of sensitive fish species (Sukhodolova et al., 2017).

Therefore, also in this case it is desirable to create varying profiles that follow the expected morphological processes (Liefveld et al., 2008). This means that steeper slopes can be created in the outer curves where erosion takes place and more gentle slopes can be created in the inner curves where sedimentation take place (ibid.). To deal with the balance between the hydraulic dynamics and the creation of a low flow zone, a deeper zone may be created behind the rehabilitation structure and adjacent to the shallow zone, which could create a water flow in the deeper part similar to figure 8b as opposed to the water movements visualized in figure 8a. A simple visualization of this solution can be seen in figure 9. This also creates the possibility for the target species to migrate to deeper parts during winter, where the temperature is more stable as opposed to the temperature in the shallow zone, which decreases at a higher rate and may result in ice formation (Van Emmerik & Quak, 2020).

Figure 8. Examples of protected riverbanks with differing enablements of water exchange (adapted from Willems & Van Winden, 2011)

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19 Figure 9. Simple visualization of the riverbank profile design that includes a deeper zone

3.8.4 Periphyton

Besides phytoplankton, periphyton plays an important part in nutrient recycling within the littoral zone by utilizing dissolved nutrients present in the water column for primary production (Wu, 2016; Singh, James & Bharose, 2017). They contain a complex mixture of heterotrophic and autotrophic microorganisms, including algae, bacteria, fungi and protozoa, that are attached to submerged surfaces (Wu, 2016), as can be seen in figure 10. Periphyton has shown to be a more efficient primary producer in comparison to phytoplankton and grazing fish species have more ease to consume periphyton, as it is attached to surfaces and substrates (Pohnke & Klinge, 2018). Stimulating the growth of periphyton may therefore positively stimulate the fish stock density (ibid.). This can be done by increasing the area of surfaces and substrates, which includes emerged and submerged water plants, rocks and dead wood, though nutrient availability and light conditions must be sufficient (ibid.). Creating variety in substrates can contribute to the diversity of periphyton types, while it also increases habitat complexity within the transition zone and can thereby contribute to the biodiversity and fish abundance (Francis et al., 2008; Geerling, 2016; Weber, 2016). The addition of dead wood has also shown to be effective to prevent of the establishment of invasive species (Leuven et al., 2018). Periphyton also plays an important role in water purification through the ad- and absorption of both nutrients and metals (Wu, 2016). Due to the competition between periphyton and phytoplankton, additional benefits are also created by stimulating the growth of periphyton, as nutrient availability for phytoplankton is decreased (Pohnke & Klinge, 2018). This decreases the risk of algal

blooms, while also creating more resilience with regard to climate change, as phytoplankton thrives under warmer temperatures (ibid.). Though the benefits of periphyton has been widely recognized, excessive growth of periphyton can create detrimental effects, including toxicity, clogging issues, and

recreational limitation (Wu, 2016). Figure 10. Periphyton visualized in freshwater ecosystems (Mann & Williams, 2014)

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3.9 Stakeholder analysis

The Zwarte Water system involves a variety of actors that have varying degrees of interest in the realization of the proposed methods. For successful and efficient implementation of the proposed strategies, recognizing the interests and characteristics of the involved stakeholders can be crucial (Prell, Hubacek, & Reed, 2009). This can be done through a stakeholder analysis, which is defined by Varvasovszky & Brugha (2000) as “an approach, a tool or set of tools for

generating knowledge about actors – individuals and organizations – so as to understand their behaviour, intentions, inter-relations and interests; and for assessing the influence and resources they bring to bear on decision-making or implementation processes”.

Reed et al. (2009) suggest there are three different approaches to stakeholder analyses, including normative, instrumental and descriptive approaches. Descriptive approaches merely describe the relationship between a system or phenomenon and its actors or stakeholders, but both the normative and instrumental approaches need this understanding as well and therefore the descriptive approach may likely be necessary to conduct a stakeholder analysis (ibid.). The normative approach commonly seeks to create common ground between stakeholders by creating a platform in which stakeholders can share and intersubjectively validate their views on the issue at stake on the basis of “communicative rationality” (ibid.). In the instrumental approach on the other hand, stakeholder analyses are instrumentally used so that the behaviour of stakeholders can be identified, explained and managed in order to achieve the desired outcomes (ibid.). Within the WFD project, the stakeholder participation process is performed according to a standard protocol of Rijkswaterstaat, which takes the form of an instrumental process. This requires an understanding of the relationship between the stakeholders and the system, therefore the descriptive stakeholder analysis is presented here. The analysis uses three steps, starting with the identification of the stakeholders. This analysis mainly involves external stakeholders, with the exception of the shipping sector that is represented by the department of traffic and water management within Rijkswaterstaat. Other internal stakeholders, that are not considered in this analysis, include the national WFD team. The stakeholders have been identified during the expert meetings and are listed in table 10.

Table 10. Identified stakeholders and corresponding objectives and activities

Stakeholder Objectives and activities

Province of Overijssel Ensure N2000 goals (Provincie Overijssel, 2017a; Provincie Overijssel, 2017b).

Municipalities Responsibility of municipal spatial planning, municipal environmental policies and the sewage system (Immink & Taal, 2005).

Landschap Overijssel - nature management organization

Ensure the conservation and restoration of nature, biodiversity and the landscape of Overijssel (Zekhuis, 2013).

Staatsbosbeheer (SBB) - national state forestry agency

Ensure nature development while creating synergy with other societal challenges, such as climate change and water safety (SBB, 2018).

Waterschap Drents Overijsselse Delta (WDOD) - waterboard

Be able to provide water safety, provide a well-functioning water system and provide purified wastewater (WDOD, 2015b). Meaning they want to provide safe, sufficient and clean water (ibid.). Shipping (commercial and

recreational)

Ensure smooth and safe navigation activities and facilities (Postma et al., 2015).

Fishery (commercial and recreational) Maintain fishing activities and facilities (Van der Meij et al., 2004)

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The second step of the analysis is the differentiation or characterization of the stakeholders. This may be executed in two ways, either using a top-down approach with analytical categorisation or a bottom-up approach with the reconstructive categorisation (ibid.). The analysis carried out here uses analytical categorisation using a popular method that locates the position of the stakeholder along two axes that show the degree of power and interest that the particular stakeholder possesses, thereby categorizing them into either “key players”, ‘‘context setters’’, ‘‘subjects’’ or ‘‘crowd’’ (Reed et al., 2009; Van Weperen, 2013). Using a non-participatory approach, this was identified using the existing literature and documents produced by the stakeholders, as proposed by Rijkswaterstaat’s protocol and due to time and resource limitations. The level of interest of

the stakeholders can be scored through the identification of their type of interest as seen in table 11(Van Weperen, 2013). In addition, the level of power was identified by assessing the sources of power as proposed by Reed et al. (2009) and Van Weperen (2013), which include formal authority, property and possession of financial resources.

Table 12. Identified stakeholders and their level of interest

Stakeholder Interest type Level of interest

Province of Overijssel

Compliance to regulations; achieving objectives and prestige 5

Municipalities Compliance to regulations; achieving objectives and prestige 5

Landschap Overijssel

Achieving objectives and prestige; education 3

SBB Achieving objectives and prestige; education 3

WDOD Compliance to regulations; achieving objectives and prestige 5

Shipping Economic dependency; leisure opportunities 5

Fishery Economic dependency; leisure opportunities 5

Public Leisure opportunities 1

Table 13. Identified stakeholders and their level of power Source of power

Formal authority Property Possession of financial

resources Province of Overijssel 3 2 3 Municipalities 2 1 2 Landschap Overijssel 0 3 2 SBB 0 3 1 WDOD 2 3 2 Shipping 3 2 3 Fishery 0 0 1 Public 0 0 1

Through the identification of the level of interest and the level of power, the stakeholders can be located in the power-interest matrix and they can be assigned their corresponding roles, which is visualized figure 11. It also shows the most effective strategy to deal with these stakeholders. For example, the key players require active grooming due to their high interest and power, while subjects are often empowered within projects as they are marginal stakeholders (Reed et al., 2009).

Table 11. Stakeholder interest type (Van Weperen, 2013)

Type of interest Value

Economic dependency (income) 4-5

Compliance to regulations 4-5

Attractive living environment 4-5

Location specific advantages (companies) 3-4

Moral reasons 2-3

Achieving objectives and prestige 2-3

Keeping or attracting members 2-3

Leisure opportunities 1-2

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22 Figure 11. Power-interest matrix of the identified stakeholders

The third step of the analysis would be to investigate the relationship between the stakeholders by identifying possible conflicts and synergies and to determine whether the relationship can be of cooperative nature. Concerning the implementation of WFD strategies, Rijkswaterstaat, the Province, the waterboard and the municipalities share the same objectives of conserving and restoring nature, but they are also strongly dependent on each other and must cooperate in order to successfully implement the strategies, as they all carry responsibility and have their own individual interest in the issue at stake (Immink & Taal, 2005; Wuijts & Van Rijswick, 2007). The objectives are also shared with Landschap Overijssel and Staatsbosbeheer and allows for synergies, therefore their relationships can also be seen as cooperative. Another reason for this is because a selection of the proposed strategies in the Policy Vision may be implemented on their properties, meaning that they will have to carry out management and maintenance activities.

Conflict can be detected between these nature objectives and the objectives of the shipping sector, as the strategies may jeopardize navigation safety, but the sector also requires a stable water level regime and channels with large water depths (WDOD, 2015a; WDOD, 2015b). This is of considerable economic importance with regard to commercial shipping activities, though relatively the Zwarte Water is used more for recreational shipping activities and is not considered one of the main waterways (Postma et al., 2015). For fisheries both conflict and synergies can be detected. The WFD strategies are expected to result in improvements in the ecological status of the waterbodies, thereby improving fish stocks, which would also benefit the fishing sector (Van der Meij et al., 2004). However, shifts in fish communities may not be beneficial for the commercial fishing sector (ibid.). In addition, the accompanying legislation may restrict the activities of the sector (ibid.). Involvement of this marginal stakeholder can be crucial for effective implementation of the proposed strategies (Reed et al., 2009).

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3.10 Concluding remarks

The internship has resulted in a Policy Vision in which the strategy plan for reaching the WFD goals have been formulated, based on the multi-criteria analysis and GIS analysis and the literature review. The proposal consisted of riverbank optimizations along a length of 18.9 km that involves the construction of steel and timber sheet pile walls, (improvement of) embankments of quarry rocks, measures on land and the connection of backwaters. In later stages of the project, a selection of these proposed locations and measures are required to finalize the realisation contract between Rijkswaterstaat and Lievense to meet the 8.3 km requirement. In addition, the literature review of the establishment of the transition zone behind the rehabilitation structure can serve as a starting point for the design phase.

A few recommendations can be made for further stages of the project. Firstly, a descriptive stakeholder analysis has been performed, but it is recommended to initiate a stakeholder participation process in which a platform is created where views of different stakeholders can be shared that may lead to a learning process (Reed et al., 2009) This is especially important to tackle possible obstacles considering the tight time schedule that has been laid out for this project. Secondly, the proposed solutions with regard to the ecological requirements of the riverbanks require further investigation in order to determine which solution is best suited in this situation to offer the balance between the reduction of the hydraulic dynamics and the assurance of maintaining the water exchange and connectivity with the main channel. This is essential, as the risks associated with decreased hydraulic dynamics can considerably impact the habitat suitability and inefficient designs may jeopardize the WFD goals. Finally, it is also recommended to ensure that monitoring of all relevant variables before, during and after the construction is performed, as this knowledge is not only valuable for adequate management, but it is also needed for knowledge transfer to other stakeholders (Zuideveld-Vennema, Willems & Wijbenga, 2011). Though this task will likely be assigned to another party rather than Lievense. This may be connected to an adaptive management cycle, in which knowledge that has been acquired during monitoring processes is utilized to adjust management strategies, which also requires the participation of stakeholders (Rist, Campbell & Frost, 2013).

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4. Personal reflection

As this was not connected to my thesis project, the aim of the internship was to gain work experience and to apply theoretical knowledge within a practical setting. Prior to the internship, I listed the following learning objectives in the internship description:

• To acquire and understand theoretical knowledge on the improvement of aquatic ecosystems

• To understand the geo-ecological processes within these ecosystems, as well as the socio-ecological interactions

• To understand how to manage ecological processes and ecosystem responses • To apply the acquired knowledge and skills on ‘real world’ situations

• To develop skills within the implementation of integrated strategies

I can confidently say that I have reached these objectives, as I have gained a considerable amount of knowledge about aquatic ecosystems and how to deal with negative impacts as a result of human interferences, for example through adaptation. Through this project I have gained an impression on how to apply theoretical knowledge, gained through research, on ‘real world’ situations, which can be very complex due to other socio-economic processes and actors, thereby improving my system thinking skills. It has also demonstrated to me that it is not necessarily a choice between nature and society, but that it is worthwhile to explore the possibilities of creating solutions that serves both, though I have a clear realization after this project that financial limitations are an important aspect as well. In addition, I have also become more familiarized with hydrological and constructional topics. This is also the case when it comes to sustainability and circularity, which has been an important part of my bachelor studies. This has made me realize again that these should remain central themes and that there is in fact increased awareness within society on these topics, making it easier to apply this within similar projects.

I have also gained more practical skills. Through the collaboration with the GIS specialist I have gained further knowledge about GIS, but more importantly it has made me more excited to use it in the future, as I have not been necessarily interested in GIS during my bachelor. Though I gained knowledge about stakeholder participation during my studies, I have not really been familiar with practical application and the broad variety of methods to perform stakeholder analyses and participation processes. Although I did not perform this practically, it did demonstrate the importance of stakeholder participation and I think my gained knowledge will be very valuable for my future career. I have also had the opportunity to considerably develop my collaborative skills, despite it being in a digital setting due to the corona crisis, which was surprisingly successful. I also appreciated that I was able to improve my writing skills within a more governmental or professional setting, rather than in an academic setting.

All in all, it was a very successful and educational internship, despite me being homebound, and I believe the internship has well prepared me for work outside academia. The company offered a professional, yet fun and (in a way) an informal atmosphere in which I had the space to develop myself and to explore the activities and topics that I thought was interesting. I have met very nice and inspiring people and I have had a great time at Lievense!

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WFD 2027: Fish habitat restoration along the Zwarte Water through riverbank optimization