Manly Ocean Beach

A Coastline Management Plan (CMP) and associated Emergency Action Plan has been prepared for Manly Ocean Beach  in response to legislative requirements for the management of community land under the Local Government Act 1993, in response to community issues and in accordance with current best practice for the management of coastal foreshores. 

Stage 1 of the project comprises the Manly Ocean Beach Coastline Management Study which identified issues and set objectives to be addressed by the Coastline Management Plan. The study also provides a general review of the planning systems and management frameworks relevant to the study area, which were considered when developing management options included in the Coastline Management Plan. 

The Manly Ocean Beach Coastline Management Plan develops a blueprint for the future management of the Ocean Beach area. The Coastline Management Plan will be used as an important resource to guide community action and to assist government and the Council in the ongoing management of the ManlyOceanBeach, coastal reserves and foreshore areas. 

The Manly Ocean Beach Coastline Management Plan has taken a number of diverse considerations into account, including: 

Implications of coastal planning policy and guidelines and local, regional and State planning instruments; 

The type and nature of coastline hazards, including risk and potential damage to coastal developments and amenity; 

Aesthetic, recreational and ecological values of the particular section of the coastline under consideration (through community and stakeholder consultation); 

Social factors, including the needs and desires of the community, the social disruption and other intangible costs of potential damage, and the physical and psychological effects of damage (through community and stakeholder consultation): 

Long term considerations of climate change; and 

An economic analysis of proposed or existing development, including expected costs and benefits to both the public and private sectors, based on options to develop, redevelop or leave undeveloped an area of the coast.

The overall objective for the preparation of the CMP is to develop a long-term management strategy to guide the sustainable management of the Plan’s study area now and in the future. 

The CMPs that have been developed are intended to be 10-20 year strategic plans. Implementation of the CMPs will involve considerable capital expenditure, which will need to have regard to other Council priorities. 

Manly Ocean Beach Emergency Action Plan for Coastal Erosion

Changes to the provisions of the Coastal Protection Act (1979) during 2004 resulted in Council also being required to develop emergency response mechanisms for the Manly Ocean Beach study area. As such, the Manly Ocean Beach Draft Emergency Action Plan has also been prepared. 

The Emergency Action Plan: 

Identifies roles and responsibilities of stakeholders in emergency management before during and after storm event (Council, SES, Police, BoM etc); 

Includes the identification and assessment of individual physical protection measures (Geobags, basalt rock, concrete blocks) and their appropriateness for use on Manly Ocean Beach;

Identifies preferred physical protection measures; 

Outlines the required approval process for implementation of physical emergency protection measures.

Council's Role in Emergency Management 

Before the storm

  • development of CMP/EAP 
  • consultation with community, Coastline C’ttee, state govt agencies 
  • education independently and in conjunction with SES 

During the Storm 

  • Monitoring of coastal erosion in consultation with SES to identify need for evacuation and/or implementation of physical protection measures. 

After the storm 

  • Mitigate impact of any physical protection measures
  • Liaise with state government to determine changes to coastal zone and identify need for amendments to CMP/EAP 

Assessment of Emergency Protection Measures 

  •  ‘do nothing’ option unanimously rejected by Manly Councils Coastline Committee (23 August 2006); 
  • Building relocation does not apply as the form of existing structures does not allow for relocation in an emergency; 
  • Sand dumping not viable due to scale of erosion hazard along MOB and lack of easily accessible/suitable sand sources; 
  • Beach scraping is not feasible as it does not involve the net addition of sand to meet erosion demand at times of major storms. 

Summary and Preferred Approach

  • It is estimated that the maximum length of seawall requiring emergency protection will total no more than 200m; 
  • Use of concrete blocks (normal density) is considered the best physical emergency protection measure due to ease of storage, handling and placement, and removal; 
  • Geobags should form a secondary physical emergency protection measure.