A jetty at Speers Point and a jetty at Fassifern are the same structure in different worlds. Three things about your shore decide how yours gets built, repaired and approved — and all three can be read off the state's own maps before anyone visits.
Get a Quote →NSW estuary data puts Lake Macquarie at 114.1 square kilometres of water with a 604.4 square kilometre catchment and an average depth of 5.7 metres, and classifies it as a lake with a “permanently open, trained entrance named after its adjacent town, Swansea.” That entrance is the only way between the lake and the ocean — Transport for NSW calls Swansea Channel “the only entrance to the popular boating area in the Hunter region” — and they keep it navigable by dredging. A trailer boat can launch from any of the ramps around the shoreline and never go near it. Anything that lives on the water, or wants to reach the ocean, goes through the channel and under the Swansea bridge.
Two structural consequences follow from that geography before you look at any particular shore:
A contractor whose barge lives outside the lake brings it in through Swansea Channel and its opening bridge, and that mobilisation is a fixed cost that lands on your job whatever its size. A contractor already working on the lake does not pay it. Which one quotes matters more on this lake than almost anywhere.
NSW estuary data records a local tidal range of 1.18 m on the ebb and 1.16 m on the flood, from a tidal prism measured in 1996. Those belong to the exchange through the mouth, not to your frontage — the entrance damps the tide heavily, which is why Council's Development Control Plan treats mean high water on the lake as one level. Its own words: mean high water is determined as +0.132 metres on the Australian Height Datum (AHD), and it “should be used for controls in this section”. The DCP adds that this figure is not to be used to work out the Foreshore Building Line under the LEP. Deck heights, pile-top heights and the splash zone are all set against that datum, so do not set anything off a 1.2 metre range.
Wind makes waves across open water, and the distance it blows across is the fetch. Wave height grows with fetch, but not one for one: in standard coastal engineering practice it rises with roughly the square root of it, so four times the open water in front of you means about double the wave height, not four times. A shore with fourteen kilometres of open lake in front of it takes a different sea from one tucked into a two-kilometre bay. What that means for how yours should be built is a question for whoever designs or repairs it, against AS 4997, and not something to settle off a table.
The tables below come from the NSW Spatial Services lake and suburb boundaries: for every suburb whose boundary meets the water, the longest straight line of open water reachable from its shoreline, and the compass direction it runs. It is geometry, not a wave study — it tells you which way your shore is exposed and roughly how much, and nothing about any single property.
| Suburb | Longest open water | Toward | Seagrass mapped at this shore | Mangrove |
|---|---|---|---|---|
| Swansea | 14.6 km | N | extensive (530.1 ha) | 89.9 ha |
| Speers Point | 14.5 km | S | little (8.3 ha) | trace |
| Belmont | 14.4 km | SSW | extensive (274.1 ha) | 3 ha |
| Gwandalan | 14.2 km | NNE | present (83.2 ha) | trace |
| Marmong Point | 13.4 km | S | present (45.8 ha) | 1.7 ha |
| Suburb | Longest open water | Toward | Seagrass mapped at this shore | Mangrove |
|---|---|---|---|---|
| Dora Creek | 9.5 km | E | extensive (264.7 ha) | 33.2 ha |
| Nords Wharf | 9.4 km | NNW | present (36.5 ha) | trace |
| Cams Wharf | 9.1 km | NW | present (11.3 ha) | — |
| Pelican | 9 km | NNW | little (8 ha) | 10.9 ha |
| Fennell Bay | 8.9 km | SSE | little (2 ha) | trace |
| Valentine | 8.7 km | S | present (83.2 ha) | — |
| Wangi Wangi | 8.7 km | SSE | present (64.1 ha) | — |
| Toronto | 8.6 km | SSE | present (92.5 ha) | 3.1 ha |
| Morisset | 8.6 km | ENE | extensive (129 ha) | 16.1 ha |
| Murrays Beach | 8.6 km | NW | none mapped (0 ha) | — |
| Kilaben Bay | 8 km | SSE | present (14.3 ha) | 1.3 ha |
| Bolton Point | 7.9 km | SSE | present (58.7 ha) | — |
| Bonnells Bay | 7.9 km | ENE | present (84.9 ha) | 1.2 ha |
| Summerland Point | 7.6 km | N | extensive (119.8 ha) | trace |
| Belmont South | 7.5 km | NW | extensive (120.6 ha) | trace |
| Marks Point | 7.5 km | NNW | extensive (172.2 ha) | 4.9 ha |
| Coal Point | 7.3 km | N | present (50.6 ha) | — |
| Warners Bay | 7.2 km | SSW | present (22.6 ha) | trace |
| Wyee Point | 7.2 km | ENE | present (18.5 ha) | 1.6 ha |
| Arcadia Vale | 7.1 km | ENE | present (27.5 ha) | — |
| Carey Bay | 7 km | NNE | little (7.1 ha) | — |
| Rathmines | 6.5 km | SSE | present (55.7 ha) | 2.4 ha |
| Morisset Park | 6.4 km | SSE | present (16.1 ha) | trace |
| Chain Valley Bay | 6.4 km | NNW | extensive (136.8 ha) | 3.6 ha |
| Suburb | Longest open water | Toward | Seagrass mapped at this shore | Mangrove |
|---|---|---|---|---|
| Fishing Point | 5.9 km | ENE | present (37.6 ha) | — |
| Mannering Park | 5.8 km | NE | present (60 ha) | 7.5 ha |
| Buttaba | 5.6 km | SE | present (21.2 ha) | trace |
| Sunshine | 5.6 km | NNE | present (22.3 ha) | — |
| Silverwater | 5 km | E | present (16.7 ha) | — |
| Mirrabooka | 4.9 km | S | present (10.5 ha) | trace |
| Eleebana | 4.8 km | SSW | present (38.7 ha) | — |
| Brightwaters | 4.7 km | SSW | present (34.5 ha) | trace |
| Yarrawonga Park | 4.5 km | NNE | little (5.8 ha) | — |
| Windermere Park | 4.1 km | ESE | little (3 ha) | trace |
| Croudace Bay | 4 km | WSW | present (19.4 ha) | — |
| Booragul | 3.8 km | ESE | little (3.2 ha) | 1.5 ha |
| Teralba | 3.8 km | SSE | present (22 ha) | 14 ha |
| Balmoral | 2.9 km | SSE | present (15.7 ha) | 1.7 ha |
| Blackalls Park | 2.3 km | ESE | present (42.5 ha) | 4.5 ha |
| Fassifern | 1.4 km | SSE | present (17.8 ha) | 1.7 ha |
“Toward” is the direction the open water runs away from your shore — so it is the direction wind has to come from to build the biggest sea against you. The Bureau of Meteorology publishes wind roses for long-record stations; the direction that matters for your jetty is the one that lines up with your longest run. A Belmont, Marmong Point or Speers Point shore looking down the length of the lake and a Swansea or Gwandalan shore looking back up it are the exposed ends. The western bays — Fassifern, Blackalls Park, Balmoral, Teralba — are sheltered by comparison, and their problems tend to be different ones.
NSW DPI Fisheries maps every seagrass, mangrove and saltmarsh patch in the estuary; the current Lake Macquarie mapping is from August 2021. Lake-wide it records roughly 2,260 hectares of Zostera, 181 hectares of Posidonia and 25 of Halophila seagrass, plus about 253 hectares of mangrove and 129 of saltmarsh. Seagrass is not a curiosity here. It is the single most common reason a straightforward jetty job stops being straightforward.
Why it matters structurally and legally, all from the rules already on this site:
The tables above show how much is mapped within each suburb's boundary. The suburbs with more than a hundred hectares of seagrass inside them are Belmont, Belmont South, Swansea, Marks Point, Morisset, Dora Creek, Summerland Point, Chain Valley Bay. The only lake-fronting suburb with none mapped at all is Murrays Beach. Everywhere else has some, and “some” is enough to change a job — what counts is whether it is at your frontage, which the DPI map will show you to the metre.
The estuary data lists “sand flats, mud flats and deep open waters” among the lake's habitats, and the bed genuinely varies bay by bay. We have not found a public shore-by-shore substrate map to point you to, so this page does not pretend to one. What can be said honestly:
A pile in soft mud carries load by friction along its length. Too little embedment and it creeps down under the deck — the dropped corner. The answer is a deeper pile, not a bigger one, and the depth is set by what the ground does when the first one is driven.
Where a jetty meets a rocky or rock-protected shore, the pile may stand in material that can shift around it. That is the “rock coming away from around the pile” an owner notices before anything else does. It is a foundation question, not a timber one, and it changes the scope.
The DCP fixes jetty length as the shortest of the length needed to reach a water depth of −1.5 metres at the jetty end at all times, or 30 metres into the Lake from the mean high water mark. The bed decides how many piles it takes to get there and how deep each goes. A contractor who works the lake usually knows the answer for your bay from the last job on it.
The third thing about your shore is whether the land side is yours. Much of the lake's frontage sits behind a foreshore public reserve or a road, and on Lake Macquarie that has two separate consequences.
Five things, and you now have all of them without leaving the house: your suburb; which way your shore faces and roughly how far the open water runs; whether seagrass or mangroves are mapped at your frontage; whether a truck can reach the water across your land or only a barge; and photographs — the list is on the jetty structures page. A contractor given those five can tell you on the phone whether it is a morning's work from the shore or a barge job, and whether the paperwork on our council approval page is going to be light or heavy.
Every number on this page was computed from, or quoted from, a public authority in September 2026. Nothing was estimated from memory. Sources: NSW Spatial Services (suburb boundaries and the lake polygon, NSW Administrative Boundaries and NSW Hydrography); NSW DPI Fisheries Estuarine Macrophytes mapping, Lake Macquarie, photo date August 2021; NSW Department of Climate Change, Energy, the Environment and Water, Estuaries of NSW — Lake Macquarie; Transport for NSW, Swansea Channel dredging; Lake Macquarie City Council DCP 2014 Part 9; NSW Crown Lands licence-holder fact sheet. The open-water distances are straight-line geometry from those boundaries and are not a wave or wind study.
How to find these yourself.
On environment.nsw.gov.au, search Estuaries of NSW and open the Lake Macquarie entry for the estuary figures.
On transport.nsw.gov.au, go to Projects, then Current projects, and look for Swansea Channel dredging.
On dpird.nsw.gov.au, go to Fishing, then Habitat, for the marine vegetation mapping and the activities that need a permit.
On lakemac.com.au, go to Development, then Planning controls and development guidelines, then Local Planning Controls, then Lake Macquarie Development Control Plan, and open 9.7 Foreshore and Waterway Development.
Tell us what you need and where the property is.