Nature-based solutions for coastal management

What are nature-based solutions?

Nature-based solutions aim to enhance coastal structures, and work with natural habitats and features to provide a range of benefits to people and the environment.

Nature-based solutions for coastal management include:

  • enhancing manmade structures with ecological features, like vertipools or habitat tiles
  • enhancing natural habitats or landscapes, like sand dunes or saltmarsh

These adaptations can have the following benefits:

  • reduce flood risk
  • create habitat for wildlife
  • protect carbon stores
  • attract tourists to boost the local economy
  • provide leisure spaces

Shoreline Management Plans

Shoreline Management Plans set out a strategic approach for managing the coastline against coastal flooding and erosion risks. These Plans are hosted by the four Coastal Groups in Wales and show where: 

  • we will continue to defend the coastline
  • we could consider nature-based solutions
  • we will allow the coast to adapt over time

Where we will continue to defend the coastline, we can do this with manmade defences like seawalls, groynes and breakwaters, or we can look at using nature-based solutions.

The importance of nature-based solutions in providing cost-effective and efficient solutions to flooding and climate change risks is recognised in:

Please note, this page doesn't address coastal adaptation, managed realignment or habitat creation off-setting. You can search for projects involving these topics in the OMREG database or refer to Natural Resources Wales' Evidence Report 554: Restoring marine and coastal habitats in Wales: identifying spatial opportunities and benefits.

Terms for nature-based solutions

You will come across different terms for nature-based solutions, including: 

  • working with natural processes 
  • natural infrastructure projects
  • ecological engineering
  • greening the grey

We use the following terminology on this page:

  • grey infrastructure (manmade seawalls and breakwaters)
  • green-grey infrastructure (enhancing manmade structures with ecological features)
  • blue-green infrastructure (enhancing natural habitats or landscapes) 

You may need to use a combination of these options to provide a coastal management solution.

Green-grey infrastructure

Green-grey infrastructure means enhancing grey structures with green features, such as vertipools or habitat tiles. This can have biodiversity and ecosystem benefits.

You can plan these features into new proposals or retro-fit them to existing structures. 

Green-grey case studies

Glasgow University- Greening the Grey: A framework for integrated green grey infrastructure (IGGI)- Appendix 4: Coastal  presents green-grey coastal management innovations from academia and practice. These show designs for assets like bridges and coastal engineering structures that need to remain primarily grey for their essential function.

The reports are categorised as:

  • evidence rich and operationally tested case studies (CS)
  • ‘art of the possible’ examples that have limited data or which have not yet been applied operationally (AP)

Title and reference

Aim of the measure

Enhanced armour CS-C4

Use of more ecologically favourable armour

Seawalls: vertipools, artificial seashore habitats CS-C5 

Pocket rock pools retrofitted onto vertical sea defences

Seawalls: habitat enhancement of replacement wall CS-C6 

Habitat features added under and around a new urban coastal waterfront

Seawalls: habitat enhancement of historic wall CS-C7 

Niche habitat in stone cladded sea wall repair in a historic conservation area

Other: intertidal habitat created around a new development CS-C8 

Large scale development incorporating enhanced habitat features

Armour: Bioblock AP-C2 

Eco-engineered concrete armour units

Armour: Drilled core rock AP-C3 

Retrofit habitat added to breakwater rock armour

Armour: Pits and grooves AP-C4

Retrofit habitat added rock armour

Armour: Concrete rock pools AP-C5

Designing habitat into concrete shed units

Armour: Breakwater AP-C6

Retrofit habitat added to concrete armour units

Textured concrete for biodiversity AP-C7

Testing tiles for designing habitat into sea walls and armour

Textured concrete for sea walls AP-C8

Testing tiles for designing habitat into sea walls

Bio-protection of sea walls AP-C9

Using biology to improve asset resilience

Other: Eco-enhanced storm water outfalls AP-C10 

Retrofit habitat added to outfall cover

Green-grey projects

Ecostructure is a project raising awareness of eco-engineering solutions to the challenge of coastal adaptation to climate change by providing developers and regulators with accessible tools and resources, based on interdisciplinary research in the fields of ecology, engineering and socioeconomics.

The Mumbles Sea-Hive Project. The purpose of the Mumbles Sea-Hive project is to research how we can create an eco-friendlier seawall.

The Marineff Infrastructures aims to enhance and protect the ecological status of cross-channel coastal waters and includes the application of nature-based solutions on flood defence structures.

The World Harbours Project (WHP) promotes eco-engineering and other approaches that will help build ecological resiliency into urban ports and harbours.

Seattle's sea wall was designed to improve marine habitats, with a special focus on encouraging juvenile salmon migration.

The Biodiversity of Marine Artificial Structures synopsis covers published evidence for the effects of global conservation interventions aimed at enhancing the biodiversity of marine artificial structures. 

Blue-green infrastructure

Blue-green or natural infrastructure projects use existing or enhanced natural landscapes (saltmarsh, sand dunes and wetlands) to increase resilience to climate impacts.

Glasgow University- Greening the Grey: A framework for integrated green grey infrastructure (IGGI)- Appendix 4: Coastal provides example case studies of blue-green infrastructure projects.

The reports are categorised as:

  • evidence rich and operationally tested case studies (CS)
  • ‘art of the possible’ examples that have limited data or which have not yet been applied operationally (AP)

Title and reference 

Aim of the measure

Salt marsh on sea defence repairs CS-C1

Salt marsh creation on failing defences

Urban salt marsh creation CS-C2

Urban re-alignment creating salt marsh habitat

Intertidal vegetated terraces CS-C3

Reed beds added in front of sheet piling defence

Bee banks CS-M1

Altered mowing on earth embankment defences

Vegetated: Tidal mudflat creation AP-C1

Repair piling incorporating tidal habitat

Beach nourishment

Beach nourishment is the process of adding material like sand or shingle to the shoreline to improve or restore beaches and their coastal defence functions. 

The following report looks at 10 sample sites where beach nourishment might be an appropriate management option over the next 20, 50 and 100 years: 

'Beach nourishment operations in Wales and likely future requirements for beach nourishment in an area of sea level rise and climate change CCW Science Report No.928' (Countryside Council for Wales)

Contact library@cyfoethnaturiolcymru.gov.uk to request a copy.

Working with natural processes to reduce flood risk - case studies 46 to 65: coasts and estuaries has the following case studies about beach nourishment:

Title 

Summary

Case study 61: Pevensey Sea Defences

Replacing material lost from the bay frontage with dredged and bypassed material.

Case study 62: Poole Bay Beach Replenishment Trial

Adding dredged sediment to the nearshore to allow waves and tidal currents to move the it towards and along the beach.

Case study 63: Pagham Harbour Bypassing

The bypassing of shingle beach material from one location to another

Case study 64. Shoreham Harbour Shingle Bypassing and Recycling

A shingle transfer operation to replicate natural longshore drift, which was previously obstructed. 

Case study 65: Sandscaping

Adding sediment in one location, in a way that natural processes move it to other places where it is needed.

Sand dune management

Sand dune management for flood defence involves restoring eroded areas and stabilising others using fencing, thatching and vegetation planting techniques. The idea is to help, not obstruct the dune-forming processes to conserve the dune ecosystem.

Working with natural processes to reduce flood risk - case studies 46 to 65: coasts and estuaries has the following case studies about sand dune management:

Title 

Summary

Case study 59. Hightown Sand Dune Restoration

A project to restore sand dunes to their late 1970s extent

Case study 60. South Milton Sands

A project between 2003 and 2009 to remove failing defences and reprofile the dunes. This allowed them to shape according to natural processes.

 

Advice on Options for Sand Dune Management for Flood and Coastal Defence, NRW Evidence Report 207 (Volume 1 Main report and Volume 2 Site Summaries) The report provides a new assessment of the environmental setting, geomorphological character, shoreline management plan (SMP) context and significance of Welsh dune systems

Sand dune management for flood and coastal defence This project explores the physical processes taking place in sand dunes and the best way of managing them for defending the coastline.

Sands of LIFE is a NRW project to revitalise sand dunes across Wales, which runs until December 2022. 

Dunes 2 Dunes - Sustainable management of Bridgend's Coastal Landscape is a project to preserve and enhance the two remaining sand dune landscapes in Bridgend County Borough Council.

Dynamic Dunescapes is an ambitious project, rejuvenating some of England and Wales' most important sand dunes for people, communities and wildlife

Natural England's climate adaptation manual - Chapter 27 Coastal sand dunes supports practical decision-making, by bringing together recent science, experience and case studies. 

The West Sands Dune Management project has examples of nature-based dune enhancements to undefended coastline in north-east Scotland. 

Saltmarsh and mudflat management

Saltmarshes and mudflats can reduce and dissipate wave and tidal energy in front of flood defences and can extend their design life.

Examples of techniques used for saltmarsh management include: 

  • the use of dredged sediments which are placed over, or around, saltmarshes and intertidal mudflats to either create habitat or protect intertidal habitats from ongoing erosion
  • installation of fences in a rectangular pattern, with brushwood materials (e.g. willow branches) inserted between fence posts. This slows strong currents and reduces wave movements, so that sediment can more easily settle out of the water column.

Rumney Great Wharf Saltmarsh Restoration / Enhancement Feasibility and Preferred Option Studies, Report No: 528. A NRW study to look at using nature-based solutions to enhance or extend saltmarshes. 

The Saltmarsh Management Manual includes details of a number of techniques that can be applied for maintaining, restoring, enhancing or creating saltmarsh.

Working with natural processes to reduce flood risk - case studies 46 to 65: coasts and estuaries has the following case studies about beach nourishment:

Title 

Summary

Case study 47: North Norfolk Coast

Managing coastal flood risk by using seawalls and natural barriers.

Case study 53: Rye Harbour Farm Regulated Tidal Exchange

A scheme to provide a tidal storage area and a creek system directly linked to the Rother transitional water body.

Case study 55: Sandwich Tidal Defence Scheme

A scheme to strengthen and improving existing tidal river defences, and create a tidal flood relief area between Sandwich and the mouth of the River Stour.

Case study 56: Levington Saltmarsh Restoration, Suffolk

Moving dredged material by fixed pipes to an area where the saltmarsh has degraded and fragmented. The ends of the pipes are moved each year to change where the dredged material goes

Case study 57: Rhymney Great Wharf

The use of polders to regenerate mudflats and increase protection to the wharf scarp. 

Case study 58: Waldringford Flood Defence Scheme, Suffolk

Raising and widening a clay embankment, and restoring saltmarsh.

Chapter 23 on Coastal floodplain and grazing marsh and Chapter 28 coastal saltmarsh of Natural England's climate adaptation manual are available to download as standalone documents.

Shingle management

Traditionally, coastal defences like groynes and breakwaters restrict shingle movement along the beach.

While this can protect communities and infrastructure behind the defences, this can interrupt the sediment supply in neighbouring areas, which may cause coastal erosion.  

Alternative ways to manage shingle include: 

  • beach re-profiling
  • shingle re-cycling 
  • beach nourishment

Advice on Sustainable Management of Coastal Shingle Resources, NRW Evidence Report No. 273 has been prepared to inform the development of guidance relating to FCERM intervention works in order to protect the wider interests of shingle features in Wales.

A chapter on coastal vegetated shingle is available to download from Natural England's climate adaptation manual as a standalone document.

Scientific literature 

You can search the following evidence platforms for scientific literature about nature-based solutions: 

Nature-Based Solution Initiative Oxford

The Biodiversity of Marine Artificial Structures

The Joint Nature Conservation Committee

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