Holderness Coastal Management

Overview of Holderness Coast

Geographic and Historical Context

  • The Holderness coast is located in East Yorkshire, stretching approximately 50 km from Flamborough Head to Spurn Point.

  • It is known for having one of the fastest eroding coastlines in north-west Europe, with historical records indicating the loss of at least 30 villages since Roman times due to coastal recession.

  • The coastline is characterized by a smooth curve of cliffs and beaches, primarily composed of boulder clay, which is easily weathered and eroded.

  • The area is less than 12,000 years old, formed from glacial debris, and continues to experience significant erosion due to tidal and wave forces.

  • The predominant wave direction is from the north-east, contributing to the southward transport of sediment through longshore drift.

  • The coastline is gradually attempting to develop a shape perpendicular to the predominant wave direction, a process estimated to take between 500 and 1,000 years.

Coastal Erosion Dynamics

  • The average rate of erosion along the Holderness coast is approximately 1.7 meters per year, with significant seasonal and locational fluctuations.

  • Erosion is driven by powerful storms from the north-east, which enhance the energy impacting the shoreline, leading to increased sediment transport.

  • The presence of hard points, such as the chalk cliffs of Flamborough, interrupts the natural erosion process, leading to the formation of new bays as the coastline reshapes.

  • Coastal monitoring has been revolutionized by electronic distance-measuring devices and GPS technology, allowing for accurate and rapid surveys of erosion and sediment movement.

  • The local authority has maintained a monitoring program for over 50 years, utilizing over 110 fixed points along the coast to track changes.

  • The long-term implications of erosion include increased wave energy at defended headlands, raising concerns about the sustainability of coastal defences.

Coastal Management Strategies

Current Coastal Protection Measures

  • Coastal protection is implemented at key settlements including Bridlington, Hornsea, Mappleton, and Withernsea, as well as at critical infrastructure like the Easington gas terminal.

  • The coastal defences include a mix of 19th-century structures and modern upgrades, with a total of 11.4 km currently protected.

  • Specific measures at Withernsea include 2.26 km of concrete seawalls, timber groynes, and rock armoring, with recent upgrades to enhance protection.

  • At Mappleton, defences constructed in 1991 involved 61,500 tonnes of rock armor to protect 450 meters of cliff line, including two groynes and a sloping revetment.

  • The cost of coastal protection works is significant, often exceeding £10,000 per meter, which complicates funding decisions for areas outside main settlements.

  • The overall control of coastal defence systems falls under the Department for Environment, Food and Rural Affairs (DEFRA), which oversees local authority initiatives.

Shoreline Management Plans (SMPs)

  • SMPs are strategic documents that assess risks associated with coastal processes and outline policies to mitigate these risks to both people and the environment.

  • One key principle of SMPs is to avoid interfering with natural processes unless necessary for the protection of life or property.

  • The SMPs categorize coastal defence options into four strategies, including 'do nothing' in areas without current protection and 'hold the line' where existing defences are critical.

  • The plans are designed to provide long-term guidance for coastal management, ensuring that decisions are made based on comprehensive risk assessments.

  • Local authorities are encouraged to develop these plans to address specific coastal challenges and adapt to changing environmental conditions.

  • The implementation of SMPs is crucial for balancing human needs with environmental sustainability.

Introduction to Coastal Management Policies

Principles of Shoreline Management Plans (SMPs)

  • SMPs aim to reduce risks to both people and the natural environment, ensuring that natural processes are preserved unless necessary for protection.

  • The fundamental principle is to avoid interference with natural processes unless it is essential to protect life or property.

  • Policies are designed to balance human needs with environmental sustainability, considering long-term impacts of coastal erosion and flooding.

  • Regular reviews of SMPs are essential to adapt to changing environmental conditions and human activities.

Coastal Defence Options

  • There are four main strategies for coastal defence: Do Nothing, Hold the Line, Advance the Line, and Retreat the Line.

  • Do Nothing: This approach is exemplified in Bridlington, where existing seawalls and groynes are maintained without further intervention.

  • Hold the Line: Involves monitoring and improving existing defences to maintain current protection levels.

  • Advance the Line: This strategy entails building new defences further out to sea, which can be costly and complex.

  • Retreat the Line: This involves relocating infrastructure and allowing natural processes to take over, which can be controversial among local stakeholders.

Case Studies of Coastal Defence

Bridlington Coastal Defences

  • Bridlington features 3.6 km of high masonry and concrete seawalls, complemented by groynes to stabilize beaches.

  • The seawalls have been upgraded to cope with rising sea levels, incorporating wave-return profiles to enhance their effectiveness.

  • The strategy aims to protect local infrastructure and tourism, which is vital for the local economy.

Easington Gas Terminal Protection

  • Easington is home to major North Sea gas terminals, which are at risk due to ongoing cliff erosion.

  • A 1 km long revetment was constructed using 133,000 tonnes of rock to protect the terminal while minimizing disturbance to nearby Environmentally Sensitive Areas (ESAs).

  • The design of the defences allows for natural sand movement, reducing the impact on coastal processes.

Hornsea Coastal Defences

  • Hornsea's protection includes 1.86 km of concrete seawalls, groynes, and rock armour, designed to safeguard the town and its resort functions.

  • Recent upgrades have increased seawall heights to address the challenges posed by rising sea levels and increased storm intensity.

  • The coastal management strategy here reflects a balance between protecting human activities and maintaining natural processes.

Environmental and Economic Considerations

Impact of Coastal Processes on Local Communities

  • Coastal erosion has significant implications for residents and businesses, leading to conflicts over the need for protection versus environmental preservation.

  • Local stakeholders, including residents and business owners, often advocate for stronger coastal protection measures to safeguard their properties.

  • Conversely, environmentalists argue that additional protection can disrupt natural sediment supply, leading to further erosion in other areas.

The ‘Roll-Back’ Policy

  • The roll-back policy encourages the gradual relocation of caravan and holiday parks situated within 200 meters of the coast to mitigate risks from erosion.

  • This policy aims to maintain the local economy while ensuring safety from coastal hazards.

  • Local planning guidelines restrict new developments within 30-100 meters of the coastline, promoting sustainable land use.

Future Challenges and Adaptations

Climate Change and Coastal Management

  • Climate change is expected to exacerbate coastal erosion and flooding through increased storm intensity and sea-level rise.

  • Effective coastal management requires ongoing monitoring and adaptation to changing environmental conditions.

  • Policymakers must balance the needs of local communities with the preservation of natural ecosystems, particularly in sensitive areas like ESAs.

Long-Term Planning and Review

  • The Holderness SMP was completed in 1998 and is subject to regular reviews to adapt to new data and changing conditions.

  • A condition of the Easington revetment project is to reassess its necessity in 25 years, allowing for potential removal if the gas terminals are no longer needed.

  • Long-term planning must consider both human and environmental needs to create sustainable coastal management strategies.