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SARCC - Sustainable and Resilient Coastal Cities Interactive Visualisation Tool
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Project Design Development Framework
Overview
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Longue Duree
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Urban Project Baseline
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Vision
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Strategies
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Urban Project Review
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Design & Benefits

Overview

The academic partners with SARCC project conceptualized and developed the methodology Nature-Inclusive Urban-Coastal Management- Framework (NUM). This is a Project Guide for the Implementation and Monitoring of Nature Based Solutions (NBS) to create Climate Resilient Coastal Cities. It is specially developed for professionals working in the field of urban (coastal) developments in municipalities and consultancy offices to support the inclusion of nature as a way of coastal protection. The NUM charts the development process from initiation to construction, maintenance and feedback.

Each of the proposed NBS within the pilot sites were constructed despite constraints brought about by the Covid pandemic, albeit that the time scale of the SARCC project meant that monitoring is in its early stages. Accordingly, this section of the visualisation tool presents a quick and easy to use demonstration of the Project Design Development Framework (PDDF), which is an instrument within the NUM that steps through the initial phases of the proposed coastal development to the final design that ultimately resulted in construction. Examples are provided from the various pilot sites to demonstrate the different phases of the PDDF. This includes the planned benefits of the NBS, where sufficient empirical data has been gathered for the outcomes of pilots to be quantified. For more detail for all the pilot and case study sites, see the Guidance Booklets here and the Urban-Coastal Mangagement-Framework here.

The six key stages of the PDDF are punctuated with cross-sectoral dialogue through stakeholder workshops that explain the synergies between stages and elements of the Framework. Click the image below to view a larger version.




The Longue Durée

The longue durée, or the ‘long view’, provides a historical context to the current coastline through the charting of its natural and anthropological evolution. The patterns of change over time can provide valuable information for urban coastal planners.

The project shows how an assessment of the Longue Durée provides an understanding of causal mechanisms that have shaped the coastline. Where these processes are identified as ongoing, this can inform coastal managers about the long-term forces acting on the coastline and contribute to a positive decision-making process. This provides historically derived baseline data that can be firmly integrated into the Project Design Development Framework.

The initial stage is to build ‘Atlases’ that bring together datasets for analysis. The Maritime Atlas includes artistic, cartographic, photographic, archaeological, and geomorphological data. The strategy has the added benefit of recovering representations from historical documents and artworks can be a very valuable tool when telling the story of the transient nature of a coastline to the public.


Maritime Atlas
Purpose: to evaluate the geomorphological processes and how humans interacted and intervened with the coastal landscape over time.

Archaeological Indicator Example: Western Solent, UK
The area of the Western Solent on the South Coast of the UK is a case study that has been selected as an analogue for the pilot sites. It is a perfect example of the fluctuating relationship between land and sea across millennia. Early archaeological material indicting coastal change has come from the Mesolithic site of Bouldnor Cliff that dates to the period 8,000 years ago. This was before Britain was separated from mainland Europe. Further sites covering most periods up until modern times provide temporal continuity for thousands of years. An increase in erosion is now exposing the landscapes within which the archaeology sits indicating coastal change. The archaeological record shows how people adapted to change in the past and how the changing climate and human actions have put the coastline under threat.


Remains of prehistoric forest in the intertidal zone.

Remains of a Bronze Age fish trap.

The underwater Mesolithic site of Bouldnor Cliff.

Maps and Charts Indicator Example: Belgian Coast
Historical maps and charts are a key indicator of patterns of change over time: they show not only the morphology of the coastline, but patterns of urbanisation and land usage. Longstanding structures or buildings can be used as reference points on a map and data such as the etymology of place names can be analysed to relate their relationship to the landscape.


Dunes to the West of Oostende - 1706.

The Belgian Coast, 1697, showing dunes.

Art Indicator Example: Belgian Coast
The Belgian Coast has been the subject of many works of art throughout history – works which can be used to document how the coastline and urban areas have changed over time. These images show the dune systems around Blankenberge and demonstrate that this was the natural state of the coastline before modern development. Coupled with the other data sources, we can demonstrate the effectiveness of dune systems as a nature-based solutions for much of history.


Dunes to the West of Oostende - 1706.

The Belgian Coast, 1697, showing dunes.

Images Indicator Example: Vlissingen, the Netherlands, and Southend-On-Sea, UK
Though photography has not been around as long as the ability to create paintings, they are still exceptionally useful in documenting more recent changes. Images of flooding along the Flemmish coast and at Vlissingen capture the impact on coastal towns while at Southend-on-Sea, photographs show the eroding cliff lines and changing shape of the beach. When compared to modern data, these highlight particularly vulnerable areas.


Storm in Vlissingen, 1954.

Flooded Gas Works in Southend-on-Sea, 1953


Landscape Atlas
Purpose: used to evaluate the landscape (soil and water), and urban morphology and infrastructure (historical dikes) on the regional scale.

Landscape Atlas Example: Vlissingen, the Netherlands
Vlissingen is a good example of a coastal Dutch town with an old centre within a citadel. On the east side there is a large industrial area, port and channel to the Veerse Meer. It is situated on a former island - Walcheren – which, by reclaiming land, has become a peninsula with the former island Zuid Beveland, connected to the mainland. It is encircled by a large dike, the inlands are polders that are drained by pumps 24/7. By looking at the landscape beyond the city itself, we can gather a wider view of the impact of both coastal change and potential solutions.


Planning Atlas
Purpose: using the Historical Assessment of Planning Policies to understand the past decision-making process, and the impact of the policies on spatial factors of coastline defence. Historical maps and charts can show where development of urban planning through time has impacted on the coastal landscape and interfered with natural processes.

Planning Atlas Example: Oostende, the Netherlands
The Flemish coastline is now defended by dikes but this has disrupted the natural adaptability of the old dune systems to provide protection. In Oostende and associated towns, the has resulted in a policy of beach nourishment, bringing sand from offshore. This is expensive and relentless challenge as the storms then removes the sand. This is arguably a natural solution but without a long term understanding of the coastal process that created equilibriums’ when the sand was in balance with the forces over thousands of years. This method of artificial replenishment has other drawbacks: it can seriously disrupt marine life, drain finite sand reserves, and also create ‘minor inconveniences’. The sand in Oostende blows over the dike, particularly in Raversijde-Mariakerke, just west of Ostend’s city centre. Here, the Koninklijke Baan, the Coast Tram and the cycle path run on the dike, right up against the beach. The costs related to the obstructed traffic and the clearance work can run up quickly. On top of that, the cleared sand cannot simply be thrown back onto the beach because it might be contaminated by traffic. It is then disposed of as “waste” and processed.


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Urban Projects (Baseline)

The longue durée is the process that provides the baseline for the contemporary urban landscape. In cities, it identifies the artificial terrain that has created barriers to the natural drainage, causing ‘weak’ spots, which need to be identified in order to assess their potential impact on the urban environment. In order to qualify and quantify these impacts, flood and urban atlases need to be integrated with the longue durée.

Flood Atlas
The Flood Atlas assesses the land and seascape to identifies the risks of fluvial and marine flooding. Within the SARCC project TU Delft used bathymetry, inlet boundary conditions, and coastal roughness to feed into numerical simulations (Delft3d) to test spatial solutions. Further methodological details can be found here.

Flood Atlas Example: Southend-on-Sea, UK
In Southend on Sea both water run off during storm events and marine storm surges have to be taken into account. Currently, the entire sea front is protected by hard defence structures including revetments, sea walls, and groynes to mitigate wave impact. Today, in coherence with the Thames Estuary action plan for 2100, the Southend on Sea Borough Council is promoting rebuilding and refurbishment works of the defences as they come to the end of their lifespan. Reinforcing the defence line is of concern as it may affect the link with the sea of fluvial runoff, therefore both elements should be assessed, as presented in the following figures, and taken into consideration. (Click images to expand)


Topography showing the vulnerability to coastal flooding.

Map showing the surface water flood risk, or pluvial flood risk.

Flood risk from overtopping in 2010.

Flood risk from overtopping in 2100.


Flood Atlas Example: Vlissingen, The Netherlands
In the Netherlands, marine storm surges are of particular concern. Dutch protection standards implemented in the Delta Works after the disaster of 1953 have led to protection levels along the coast, and specifically Zeeland, to resist storms that can be present every 10,000 years. The Hydra-NL model is a probabilistic model that calculates the statistics of the hydraulic loads (water level, wave conditions, wave overtopping) for the assessment of the primary dikes and structures in the Netherlands. A digital surface model (DSM) and a digital elevation model (DTM) have been generated for the area: the first includes buildings, cars, and trees (following the surfaces of the shapes present in the city), and the second one follows what should be the terrain/ground elevation. In the case of Vlissingen, a special manual filtering was applied for the trees and the cars, especially at the De Spuikom area. Finally, the bathymetry was built, the results indicated the primary streets by which water can divert to De Spuikom, and what areas are protected. The consequences of underestimating the flood risk can end in disaster as historical etchings and postcards testify.



Artwork of the flood of 15 January 1808.

Storm waves crashing over the Vlissingen Boulevard.

Animation shows Hydrodynamic simulation of Urban flooding of city center of Vlissingen (left: 30 min event and left: 5.5 hr event) (click image to view in new tab)


Urban Atlas
The creation of an Urban Atlas is a process that maps the heritage of the project area alongside the urban construction and infrastructure systems (water, energy, civil construction and ecology) against expected urban trends.

Urban Atlas Example: Southend-On-Sea, UK
Southend is one of the most densely populated areas (181,800 inhabitants) outside London. It is located on the mouth of the River Thames and served by a capillary transport network which includes multiple train stations; its waterfront has been, historically, an important leisure and recreational area. The urban structure is of sprawl-type dominated by single-family houses with gardens, whereas public and commercial services are concentrated along several high streets and recreational grounds (e.g. sport fields). Property development pressure is strong, particularly along the seafront due to its high economic value.

From a geomorphological perspective, the municipality is divided into two parts: the town centre and western part are located on high ground, while much of the sea front and the eastern part is on lowland at flood risk from the sea. However, due to soil sealing, the risk of pluvial flooding is also common along upland waterways.


The urban evolution of Southend-On-Sea (source: Junzhong, 2019). Click to expand.


Urban Atlas Example: Vlissingen, the Netherlands
In the Netherlands, there is a well-developed process that was applied to the Vlissingen pilot. The System Exploration, Environment and Sub-surface (SEES) stems from the Dutch Layers approach and has six functional layers with different dynamics, professionals and knowledge fields: people, metabolism, occupation, public space, infrastructure and subsurface. SEES connects the subsurface information, urban construction of the area, with the urban surface in order to inspire and set clear boundaries for the development of the urban surface. This process is used for analysing potential problems and should be applied to the design of urban development projects.


a) subsurface, sewer network and potential soil infiltration. Click to expand.


b) intensity of vegetation cover (darker = more intense). Click to expand.


c) roads and dikes (in black). Click to expand.


d) terrain levels (darker = deeper). Click to expand.


Urban Atlas Example: Newlyn, UK
Newlyn has a highly developed and historic coastal frontage, with a fishing port, residential houses and numerous commercial businesses. The community has always been exposed to storms but has experienced increasingly frequent sea flooding and coastal erosion in recent decades. The town is built right on the water’s edge and during heavy storms the waves overtop the breakwater, before propagating into the mouth of the Newlyn Coombe river. Houses, businesses and infrastructure situated at the mouth of the Newlyn Coombe are therefore particularly impacted by the resulting over-topping which occurs. To protect the town from the increasing risk of wave overtopping, this breakwater needs to be reinforced, raised and extended.


Storm waves in Penzance, UK.


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Vision

Once the baseline data has been gathered and the challenges to the potential impacts of sea level rise and climate change have been identified, the next step is to establish a vision that incorporates nature-based solutions into the protection of the area that can then be shared with stakeholders.

Vision: Vlissingen, the Netherlands

Ahead of any sea level rise, the preferred option was to incorporate a more natural solution rather than a continual rise in the concrete walled sea defence. An option to adapt the urban landscape and environment was preferred.

The solution proposed was to accept water over the dike during the greatest storms. The water would then be channelled down an enhanced road that would take the water to the relict Spuikom that was once a water reservoir that would fill at high tide and store water that was used to flush out the old harbour at low water.

The ‘Spuikom Model’ incorporates an overtopping sump area. Today, the Spuikom and its surrounding are the focus of a long-term vision by the municipality that aims to transform it into a mixed-use urban development (with commercial, residential, and leisure functions) serving also as a water retention basin (or “overtopping sump”) during any such exceptional flood events.


Overtopping sump model. Click to enlarge (opens in new tab).


Vision: Middelkerke, Belgium

Natural dunes systems can form a natural and solid sea defence. Where a dike is already present for example, in seaside towns a dune seaward of the sea wall can provide additional protection against floods and waves. These new dunes also provide a large sand storage area that protects beach and foreshore from erosion. In an ideal scenario, the dune ensures that the dike does not need to be raised. In addition, the dune-before-dike principle is beneficial to biodiversity and can also add value in terms of tourism.

In Middelkerke the Dune-before-dike was envisioned to take the form of a lowered promenade between the existing sea wall and the beach. On the beach side, the lowered boardwalk will have a wide breaking element that also serves as a rampart. When the water breaks during storm surges, it is collected in the lowered zone and flows back to the sea through openings at the bottom of the breaking element. In total, a 500m long stretch of grass dike was proposed as the pilot project within SARCC.


The 'Dune-before-dike' model. Click to englarge (opens in a new tab).


Vision: Oostende, Belgium

At Oostend a different approach was taken from Middlekerke where an embryonic dune formation is initiated, after which natural processes take over. Thanks to marine sedimentation (sand supplied by tides and waves), aeolian sedimentation (sand supplied by the wind) and the planting of marram grass (which retains the sand), the dune should grow by itself. Indeed, dunes are ‘living dunes’. In a natural situation, dunes can emerge, grow and recover by themselves. Marram grass plays a crucial role in this: marram grass has a densely branched and deep system of rhizomes with which it can keep up with an annual sand growth of 1 m. In other words, marram grass is able to grow with the shifting of sand.


Monitoring dune height in Oostende. Click to enlarge (opens in new tab).


Vision: Blankenberge, Belgium

Blankenberge conceived the plan to dismantle, one lane of the Koninklijke Baan over a length of 700m and return it to nature. At that spot, between the Koninklijke Baan and the beach, there is an elongated and valuable dune area with dune lakes and wet dune grasslands. Plans are to break up an 11 m wide strip (6,700 m2 of road surface would be depavaed, the footpath, cycle path, parking lane, two driving lanes and another parking lane) so all that remains is a recreational cycle path, surrounded by embryonic dune formation. This will create a dune-before-dike widening the existing dune foot over a distance of 700m with the dune growing inland.


Vision: Gravelines, France

The Gravelines vision is to take advantage of the natural supply of sand deposited by the sea currents on the beach and the foreshore, which the wind then blows further towards the coastline. Developing a simple system of wooden fences that stop sand from being blown will create a natural sea wall that is high enough to protect from rising sea levels. The sand accumulates around the fences, after which vegetation such as marram grass will take over. Marram grass fixes the sand and increases the stability of the dune area. Elevated, wooden paths are constructed to enable visitors to walk through the dune in a controlled manner. The paths were designed to face east to take into account the sand currents caused by the wind.



Vision: Newlyn, UK

To protect the town from the increasing risk of wave overtopping, from the Coombe River it was envisioned that the breakwater needsedto be reinforced, raised and extended. The current breakwater is made up of traditional granite rock. This smooth granite surface is difficult for marine life to settle on and does not attract a wide variety of species. In this pilot the Environment Agency are exploring low-carbon concrete material that is specifi­cally designed to attract marine life and where the CO2 emissions from production and trans­port are as low as possible. Rethinking the way to design and build traditional rock and concrete defences in some places.

Find out more: Video (English) - Newlyn NBS eco-reef pilot (Appin Williamson)


Dunes to the West of Oostende - 1706.


Eco-blocks from Newlyn.


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Strategies

With a vision now in place quantifiable models are developed and tested. These can then be adjusted after assessing technical considerations.

Strategies: Vlissingen, the Netherlands

To test the waves overtopping the dike scenario and then being channelled to the Spuikom, a hydrodynamic model was used to simulate a 1000 year storm. The model looked at an overtopping discharge flow values produced by a storm with a return period (RP) of 10,000 and two climate change (CC) scenarios, extreme W+ and moderate G, at the year 2100 were tested. This scenario considers a sea level rise of 1m by 2100 and a RP 1:10.000; these values are taken to perform the comparison between the current situation (baseline strategy) and the Spuikom Model for coping with sea level rise. According to the hydrodynamic model, 275,000 m3 of excess water is estimated to flood the Spuikom at the peak of the storm. On the other hand, the recovery of additional storage capacity makes it possible to achieve a retention capacity for the Spuikom of 186,000 cubic meters (140,000 m3 on S2 and 46,000 m3 on the S1). The remainder (89,000 m3) must be managed by the Watersgang. With an outflow of 5 m3/s generated by a pump installed at the opposite end of the channel, the Watersgang can drain up to 18,000 m3 over the storm duration. The remaining 71,000 m3 can be stored in the channel itself, resulting in an increase in the average water level of 0.41 m.


Climate change scenarios. Click to enlarge (opens in new tab).


Strategies: Southend-On-Sea, UK

The pilot at Southend on Sea was to consider a range of different nature based solutions , each in discreet areas located at points along it’s marine frontage from Two Tree Island in the west to east Beach in the east. While the most suitable schemes were being identified, a holistic approach consisting of four sub-strategies was taken to assesses the length of the Southend on Sea waterfront. Firstly, the topo-strategy, which focuses on place-specific water management strategies in relation to the inherited urban structure (density and typology) and soil type (e.g. rainwater infiltration in the high ground’s permeable soils, seawater retention in the low-lying impervious soils; secondly, the eco-strategy, that relies on the existing blue and green networks to reinforce their role of landscape connections and improvement of water and soil quality; thirdly, the accessibility-strategy that mainly focuses on giving priority to the active mobility (pedestrian and cycle) to provide widespread access to the seafront and finally the longue-durée strategy which places greater emphasis in research, protection and preservation of the local cultural heritage.


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Urban Projects (Revised)

This stage brings together the strategic plan with the initial vision that was developed on the basis of the atlases, and presents the outcomes of the analysis to all stakeholders and to the public. During the SARCC project, this involved a programme of workshops and events and a roadshow around the pilot areas to disseminate the vision and strategy.

Example: Vlissingen, the Netherlands

At Vlissingen, the modelling and presentation of the proposal resulted in a positive outcome to take the project forward. It identified that the overtopping of the dike into Coosje Busken Street, which would then be turned into an urban river, was viable with additional with minor physical adaptations to the street and the introduction of vegetation to channel and manage the water.


Example: Southend-On-Sea, UK

Southend-on-Sea experimented with four discreet projects rather than a single, substantial nature-based solution as was the case with the other pilots. Accordingly, an additional larger scale design was proposed for the low-lying landscape behind the sea wall at Gunner’s Park, Shoeburyness, in the south east corner of Southend on Sea. Hydraulic engineers, historians, archaeologists and representatives from the local authority collaborated to design a new urban project that explored alternatives to the costly engineering work that would be needed to raise the sea wall ahead of future sea level rise, while maximising the areas amenity and heritage value.

The innovative proposal advocated that a limited amount of overtopping was accepted into the near shore environment with a secondary defence along the existing margin between the open and built-up areas. In such a way, the area is adapted to function as a retention basin for excess water in the case of extreme events, while the existing and enhanced drainage network is used to drain the area at the end of the storm. At the basis of this idea is the principle of building a new embankment that can serve both as protection, leisure space and connection (e.g. to historical and archaeological finds along the seaside), while the new urban development inside the area is designed to be flood-proofed (e.g. by being raised on columns, or by giving ground floors to functions such as car parks).

The Overtopping sump model retains the spatial and visual connection with the sea along with the multiple benefits of water retention, habitat creation and a leisure area. The integration of the longue durée in the park design increases the legibility of the archaeological heritage and historical evolution of the area.


Find out more:
Video (Dutch): Creating support for the use of NBS (Jeffrey Beenhouwer and Marije Verlinden)
Video (English): Effective communication of climate science to broad stakeholders groups (Professor Kenny Coventry, University of East Anglia)
Video (English): How does UK funding model assist in delivering NBS? (George Arnison, Environment Agency, UK)
Video (English): How Nature-based solutions enhance traditional coastal management (Martin Davies, Environment Agency, UK)
Video (English): Capacity building: long-term thinking for decision makers and local politicians (Justin Ridgewell, Environment Agency, UK)
Video (English): MMO marine licensing for nature-based solutions (Jennifer Ford, Marine Management Organisation, UK)
Video (English): Workshop Stakeholders engagement and NBS – session one
Video (English): Workshop Stakeholders engagement and NBS – session two
Video (English): ) Coastsnap. Using citizen science to monitor coastal change (Joseff Saunders, Plymouth Coastal Observatory)
Video (English): ) Southwest of England’s climate change impacts group: taking action and working together (Emily Reed, Devon County Council)
Presentation (Dutch): ) Draagvlakvorming voor natuurgebaseerde ingrepen in de kustverdediging via ecosysteemdiensten (Annelies Boerema)
Presentation (Dutch): ) Duinen om in te struinen? Een kijk op recreatief medegebruik van de Vlaamse Kustduinen (Tim Provoost)

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Design and Benefits

A final design for the solution is created based on the previous stages and public and stakeholder feedback. The design integrates both the needs of humans and of nature. The social, environmental, and economical values should be synergised into the spatial design to enhance spatial quality and legibility.

Design and NBS Benefits: Vlissingen, the Netherlands

The NBS measure implemented in Vlissingen adapted a street so it could become a river when the seawall was overtopped and additional vegetation was planted to filter and store water. The street was redesigned toimprove the quality of the public space, while channelling excess water down the street, through and around the planted infiltration beds to a retention area (Spuikom).

This measure has multiple benefits in the coastal city of Vlissingen: flood safety, more spatial quality plus ecological, recreational and social values while respecting the historical and cultural significance of the city.

The project was successful because the design has been implemented and supported by the public, despite initial reservations. Citizens were ultimately positive about the idea of accepting water on their street and ‘turning it into a river’ to reduce the risk of flooding once they understood the concept. The municipality acted as a ‘boundary spanner’ by taking on the initiative of urban coastal flood risk within their role of spatial planning. The project is considered externally successful because mainstreaming of NBS started during SARCC. As a result of the project, the involved citizens changed their mindset about NBS for coastal protection.


Vision for the spacial quality of the area. Click to enlarge (opens in new tab).


Design and NBS Benefits: Middelkerke, Belgium

The municipality of Middelkerke initiated the project to plant vegetation and build a green dune in front of the existing dike: dune before dike. Vegetated dunes have multiple benefits for Middelkerke city: more flood safety, less coastal erosion, and more spatial, ecological, economical and recreation values. Citizens find the beach more attractive, greener and nicer for recreation. Dunes restore contact between nature and the sea. They are cheaper to construct and more flexible to manage than hard sea-wall structures which require large investments and have only a limited shelf life because of unpredictable sea level rises. With the new grass dike, Middelkerke is protected against a 1000-year storm until 2050. But if the sea level rises more, thanks to its natural structure, the dune can simply be raised giving a flexible sea wall.

The amenity value has also increased where the grass dike widens and upgrades the public space by over 100,000 m2. The area now enjoys sun throughout the day as it is not impacted by the shadows that are cast over the promenade by the flats in the morning and the afternoon.

The green dune covers a total area of 11,5 hectares from what 10,5 hectares is being planted with marram grass. In terms of carbon sequestration, a total yearly carbon capture of around 4,4 gr CO2 ha-1 of the entire project is expected. The Green Infrastructure validation tool expects an increase in land and property value of 9,5 million euros. As the project of Middelkerke might be capable of encouraging at least 3 hours of exercise per week, it’s possible to apply the reduced mortality tool. The calculated reduced mortality benefit is 167,000 euro/year, resulting in a net present value (NPV, the value in present terms, accounting for all the net benefits the project will bring over their lifetime) of 1,12 million euros over 10 years. The benefit estimation tool expects amenities to increase by 17 million euros, based on the number of visitors to the project, the average amount of spending per tourist and the real estate pricing and amount of flats in the vicinity of the projects. The savings gained from a reduction in sand cleaning due to the planted marram grass will be 384,618 euros.


Middelkerke waterfront.


Design and NBS Benefits: Oostende, Belgium

At Oostend the beach was raised creating a ‘dune-before-dike’ over a length of 700m. The principle is similar as that seen a short distance away at Middelkerke, where a green dune is planted with a covering of marram grass, meaning the dune will retain the sand, preventing it from blowing inland.

The municipality will save 11,273 € per year in cleaning costs of sand because the marram grass covered dune will act as a sink and store. Surveys in the city of Oostende revealed that tourists are willing to pay a higher price for green infrastructure when compared to residents. Moreover, 58% of the people surveyed indicated that green infrastructure at the coast is more attractive and that they would come specifically for this. This has a result on the land & property values in the vicinity of the project. GI-Val expects an increase in land and property values of 2.3 million euros.

Marram grass and additional greenery will give more possibilities and habitats for fauna and flora, thus increasing biodiversity, which is valued at an additional 2,500 euros yearly. The increase in attractiveness of the beach enhances the amenity value which is expected to be increased by 6,88 million euros.


Oostende pilot area and waterfront.


Design and NBS Benefits: Blankenberge, Belgium

At Blankenberge, the existing coastal dune has been significantly widened creating a “dune-before-dike”, providing additional protection against sea level rise.

The town of Blankenberge has invested heavily in so-called depaving projects in recent years to not only bring more nature into the city, but mainly to allow rainwater to seep into the soil. On the coast, Blankenberge suffers from a groundwater table that is far too low. This can lead to problems for the drinking water supply and for agriculture, especially in the dry but busy summer months. By enlarging the dune foot over a distance of 700m, the wider dunes provide a greater buffer against the salinisation of the polders behind, while also giving a strong boost has been given to nature and biodiversity. The fresh groundwater in the dunes creates an additional barrier against salt water ingress from the sea.

The Blankenberge project shows the highest increase in land & property values, similar to the other 2 Belgium projects, with a total increase expected of 5.96 million euros. As the Blankenberge project is the only project where tree planting is involved, it has the highest value concerning carbon sequestration. In total 351 tonnes of carbon will be sequestrated in the following 10 years, resulting in a monetary value of 24,800 euros. The biodiversity and ecology factor of the newly planted trees is expected to have a value of 1,668 euros.


Blankenberge pilot area.


Design and NBS Benefits: Gravelines, France

The project in Gravelines involved the construction of wooden piles placed strategically in front of the shrinking dune system with the aim of revegetating the existing dunes via wooden faces and replantation. Elevated wooden paths allow visitors to walk through the dunes in a controlled manner which also protects the vegetation.

These combined NBS measures have brought multiple benefits. They offer better protection against flooding, less coastal erosion and more ecological value. A higher, wider dune looks better and is good for biodiversity, plants grow more easily in a thicker dune and animals come back to the beach and roam the pilot site. The project is also popular with residents and tourists. The pilot shows that major challenges can be tackled with simple, low-cost solutions and at the same time strengthen nature and biodiversity. Unlike hard concrete structures, this nature-based solution is cost-effective.


Gravelines pilot area.



Design and NBS Benefits: Newlyn, UK

The Newlyn pilot is an investigation into the use of innovative technology, being eco-blocks in intertidal zones for the first time in the UK. The project has provided an opportunity to monitor and gather evidence of their effectiveness for future coastal management schemes that plan to ‘green’ traditional forms of hard coastal defence infrastructure. The first results from monitoring show that the eco-blocks are increasing the effectiveness of the breakwater as they are quickly colonised with marine vegetation. As a result they offer multiple environmental benefits: ecological (increase marine wildlife), spatial, recreational, social, historical and cultural.

The Newlyn pilot was a research and development initiative to test proof of concept. As the current coastal management policies encourage the implementation of NBS but do not provide a clear legal framework on how to deliver them, this innovative solution is now being studied to assess the suitability of eco-blocks as a low-carbon and nature-inclusive alternative to traditional engineered defences. If they continue to prove successful, they could be deployed elsewhere on the UK coast and provide evidence that will support the mainstreaming of NBS in the UK.


Roundhead eco blocks in the Newlyn pilot area.


Example: Southend-On-Sea, UK

Nature based solutions that were trialled in Southend on Sea included first, vertipools, being small pools fixed to hard coastal defence structures that absorb wave energy and provide an ideal substrate for marine life; secondly, a restoration of the dune system with endemic plant species along East Beach; thirdly, the creation of a green wall to protect the Two Tree Island coast from erosion and finally, the taking of a sympathetic approach to Southchurch and Thorpe Bay beaches by managing the introduction of vegetation and by reducing aggressive cleaning activities.

Monitoring is ongoing as these pilot sites had only recently been completed before the conclusion of the SARCC project, however, along Southchurch and Thorpe Bay beaches the resultsare already visible where different types of plants have started to grow spontaneously. A botanical study of the beach showed that twenty-two coastal species of halophytes or salt-tolerant plants such as sea kale, sea holly, sea lavender, Sand-hill Screw-moss and Sea Mayweed, are now thriving. In addition, the roots of the plants have stabilized the beach, reduced the impact of longshore drift and slowed down erosion. Historically, when there was a storm, sand cliffs would be cut into the beach. Now the beach remains flat, hardly any material disappears and less sand is getting blown over the seawall onto the footpath and cycle path.


Roundhead eco blocks in the Newlyn pilot area.


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