Pittwater, the other shore

A drowned river valley

Drowned river valley is the NSW environment department (DCCEEW)'s own classification for Pittwater. The department calls it a tide-dominated drowned river valley estuary with an open entrance, and describes it as a large embayment connected to the Hawkesbury River estuary where the river enters the sea.

The figures for the valley itself: a catchment of 50.8 km², an estuary area of 18.4 km², a volume of 181,836.2 ML and an average depth of 9.9 m. That depth is the first difference from the ocean side. The four lagoons behind the beaches average between 0.1 m and 2.3 m deep, while Pittwater runs close to ten metres on average, and the department's monitoring program has described its water quality as excellent, sampling five sites fortnightly between October and April since 2017, most recently over the 2023 to 2024 summer.

The land around it is moderately disturbed: urban areas to the south east, and to the north west the conservation area of Ku-ring-gai Chase National Park, the largest conservation area in the catchment. The estuary supports an endangered ecological community, coastal saltmarsh, which is habitat for many species including the endangered bush stone-curlew.

The NSW environment department (DCCEEW) classes Middle Harbour Creek as a drowned valley estuary flowing into Sydney Harbour, with an estuary area of 6.1 km² and an average depth of 13.4 m, deeper on average than Pittwater itself. Monitoring there has run since 2010 and found its water good; the most recent sampling was over the 2019 to 2020 summer, when two sites were sampled monthly. About one third of the catchment stays forested, much of it protected as part of Garigal National Park.

The swim sites on Pittwater and the harbour side, by name

Beachwatch lists each of these sites, and it gives each a description and the year its monitoring began: on Pittwater first, then the harbour.

On Pittwater

• Barrenjoey Beach, a beach about 1.5 km long on the north-eastern foreshore of Pittwater, monitored since 1996.
• Paradise Beach Baths, a 30 by 20 m netted swimming enclosure on the eastern foreshore, monitored since 1996.
• Clareville Beach, a narrow 250 m long beach on the eastern foreshore, monitored since 1995.
• Taylors Point Baths, a 15 by 20 m netted swimming enclosure on the eastern foreshore, monitored since 2010.
• Bayview Baths, a 20 by 40 m swimming enclosure on the southern foreshore, monitored since 1995.
• Elvina Bay, on the south-western foreshore, with a swimming area that is not netted, monitored since 1995.
• North Scotland Island, a 15 by 50 m netted enclosure on the north side of Scotland Island, monitored since 1995.
• South Scotland Island, at Carols Wharf on the southern side of the island, not netted and backed by a reserve, monitored since 1996.
• The Basin, a 500 m sandy beach on the western side, backed by Ku-ring-gai Chase National Park, monitored since 1999.
• Great Mackerel Beach, a 500 m long sandy beach on the north-western side, monitored since 1999.

Around the harbour

• Davidson Reserve, a 25 m long swimming area in Middle Harbour, backed by Garigal National Park and a picnic area, monitored since 1994.
• Gurney Crescent Baths, a 20 m square netted swimming area at Pickering Point in Middle Harbour, monitored since 1996.
• Clontarf Pool, a small netted swimming area in Middle Harbour, backed by a narrow sandy beach and a park, monitored since 1994.
• Forty Baskets Pool, a 20 by 40 m netted swimming area at the northern end of Forty Baskets Beach in North Harbour, monitored since 1994.
• Fairlight Beach, a narrow beach in North Harbour with a 25 m pool filled with water from the harbour beside it, monitored since 1996.
• Manly Cove, a netted swimming enclosure at the centre of the 250 m long beach, next to the Manly Ferry Terminal, monitored since 1994.
• Little Manly Cove, a 30 m square swimming enclosure at the eastern end of the sandy beach, monitored since 1994.

The western shore, at The Basin

The Basin's beach is backed by Ku-ring-gai Chase National Park, and the campground beside it is more than a swim. NPWS says it is the only place to camp in that national park, a 20 minute ferry ride from Palm Beach, with room for up to 350 campers, and calls it "the most popular camping area in the state". The Basin track is a 2 to 3 hour return walk, and on the way is The Basin Aboriginal Art site, which NPWS calls one of the best examples of rock engravings in the area.

The campground has an inland lagoon of its own, sheltered from waves and boats and suited to paddle boarding, and the national park's advice before a swim at The Basin is to check the latest Beachwatch water quality forecast. Barrenjoey Head belongs to the same national park, and NPWS places it "1km across Pittwater at Palm Beach". From West Head lookout, NPWS says, you can see Broken Bay on your left, Pittwater on your right and Barrenjoey Headland and its lighthouse in front.

More of this coast: the four lagoons between the beaches, and the five aquatic reserves.

The whole coast, Palm Beach to Shelly Beach