Chapter 8: A sustainable, protected and well managed natural and built Manly There are a number of environmental issues that emerge from a review of local, regional and state plans that impact on the Manly area. These are listed and discussed further in the paragraphs below (not in any priority order).
Protecting our Environmental Assets Although only a small LGA of 16.2km2, Manly has a diverse character of residential, business and natural landscapes with only limited industrial land uses. The area is well known for its natural environmental features, such as areas of Sydney Harbour, North Head, harbour foreshores and frontage to the Pacific Ocean. These are recognised as important and sensitive locations, and no part of Manly is more than 1.6km from a water body. As well, Manly‘s geodiversity is an important element of our natural environment. This concept covers the whole range of natural earth materials and processes. It includes the rocks, landforms, streams, beaches, soils, sediments and groundwater features. The urbanisation of Manly is typical of many regions around the world, with bushland cleared for urbanisation, many waterways channelled, diverted and piped for flood mitigation, wetlands drained and used for landfill and recreation. Manly‘s drainage system has evolved haphazardly over 150 years with the replacement of porous soils by hard surfaces such as concrete. It was designed to improve land utility and prevent flooding, with a traditional emphasis on efficiently collecting, and diverting stormwater into nearby creeks, beaches and lagoons. Little or no consideration has traditionally been given to the ‗downstream‘ consequences of this approach, leading to problems in water quality and reduced recharge of groundwater systems. More recently we have seen a shift away from ‗end of pipe‘ solutions, and focus on the application of reuse, infiltration, pollution prevention measures, and most importantly, viewing stormwater as a resource.
Climate Change in Manly The following aspects of climate change required further management at a local level: • • • •
Sea level rise – predicted to rise anywhere between 3 and 16cm in the years to 2030, and then 7 to 50cm by 20708; Coastal erosion and retreat – increases in the frequency and intensity of coastal storms and floods will have considerable impact on existing beaches and low lying residential, community uses and parklands in coastal areas in Manly in the 20-30 years; Temperatures are also predicted to rise on average by 0.6 to 1.3 degrees celsius in the period to 2030; and corresponding changes in annual average rainfall may either decrease by 3% or increase by 9% per annum9. Other climatic effects might be increases in extreme events such as flood, tidal surges, droughts, wind speeds, bushfires.
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Sydney Coastal Councils, CSIRO and University of Sunshine Coast, Mapping Climate Change Vulnerability in the Sydney Coastal Councils Group, 2008 9 Ibid MANLY Council – Community Strategic Plan
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