See Map of Middle Harbour Catchment.
The Middle Harbour catchment is north west of Sydney Harbour, with the mouth of Middle Harbour catchment between Middle Head and Clontarf. The catchment extends 14 kilometres to its northern boundary along the ridge at Mona Vale Rd between St Ives and Terry Hills. From the Pacific Highway, the western boundary, to Forest Way and the Wakehurst Parkway, the eastern boundary, the catchment ranges from between five to eight kilometres wide. The catchment has an area of approximately 100 square kilometres. Despite being a widely developed urban catchment within Sydney, one quarter of the catchment is currently bushland.
Middle Harbour is managed by a number of councils including; Ku-ring-gai, Warringah, Willoughby, North Sydney, Mosman, and Manly Councils', as well as Garigal National Park, a number of community groups and industries. It also contains about 70,000 households and 200,000 people.
The catchment area has many attributes including: beaches, rocky fjord like reaches, pristine bushland, and major CBD areas. It also hosts a camp area used in 1788 by Captain Phillip, still in pristine bushland.
Parts of the catchment are recognised on the National Trust's listing
for the Middle Harbour Landscape Conservation Area. Middle Harbour is also
host to a number of historical sites, and contains a number of rare flora
species.