Tomaree’s groundwater is at a new peak
The Friends of Tomaree National Park, in a chance encounter with a Hunter Water scientist in early August, discovered some interesting observations about Tomaree’s groundwater. Since then we’ve had more rain and the levels are even higher.
Our groundwater is over flowing
Currently the groundwater level in the Tomaree aquifer is above the 100% storage level, with water being exposed at the surface in many areas and the swamps are full.
Surface water drainage is occurring from these swamps, which has been evident for several months at locations such as Nelson Bay Road near the northern end of Frost Road, and at Gan Gan Road near the southern end of Frost Road after heavy rain.
Interestingly, despite the proximity of the Tomaree aquifer to the ocean, most of the surface water draining from the swamps is directed to the west and into Port Stephens estuary via Cromarty Bay or Mambo Swamp.
Above: Walking tracks that are usually dry near wetlands south of Salamander Way, flooded in 2022 and the creeks were full and flowing westward.
Highs and lows of Tomaree’s aquifer
The previous highest recorded groundwater level (ie. historically) in the Tomaree aquifer since records began in the late 1970s was in late 1990.
The lowest recorded storage level since records began in the late 1970s was 28% in mid-1997.
The groundwater level in the Tomaree aquifer continues to fluctuate in response to rainfall events and drainage.
Currently the groundwater is at its highest level since November 2022, and exceeds the 1990 level by 30 cms.
Anna Bay Boreline track is flooded across the track — not surprisingly given the paperbark swamp forest alongside.
Surprisingly, some cyclists using the boreline, have mentioned water on the road is nearly at their waists!.
Caption: Historical water storage levels. source Hunter Water
Some people recall significant rainfall events over the past 20 years, such as June 2007 (when the Pasha Bulker ran aground at Nobby’s Beach), April 2015 and more recently March 2022. However, the rain from these events did not fill the aquifer because groundwater levels are dependent on the prior conditions. Aquifer storage levels at these times were 40%, 60% and 99%, respectively.
The groundwater level in the aquifer dropped to the 40% storage level in mid-2007 (and remained around that level despite the east coast low event commonly known as the Pasha Bulker storm) and the aquifer dropped to just below the 50% storage level in mid-2019 during the last drought.
Tomaree residents drink the groundwater
The Tomaree aquifer supplies, on average, 80% of the drinking water to the Tomaree Peninsula. In peak visitor periods, water to the Tomaree Peninsula is supplemented from Grahamstown Dam.
Groundwater in the aquifer is of very high quality so requires minimal treatment. That helps to keep supply costs down, but the aquifer and water quality require ongoing protection to ensure that remains the case.
Most of Tomaree’s water catchment, though not all, is within Tomaree National Park, where there is a co-management arrangement between the National Parks and Wildlife Service and Hunter Water.
Pumps along the Shoal Bay and Anna Bay bore lines take water to the big tanks on top of Glovers Hill in the national park, where it is treated before being delivered to our taps.
Water tanks on the hill in Tomaree National Park are supplied from the Hunter Water borelines nearby
Wetlands in Shoal Bay closely border development and are extremely sensitive to impact from neighbours, roads, and other influences. Homes with spearpoints in their yard legally use water from our groundwater, whether we are in drought or in times of plenty. Wise use at times when water is less abundant is best.
Unfortunately, kids build unauthorised mountain bike trails and humps in the catchment which creates sediment and other issues, however the impact of illegal motorbikes in the national park has even greater impacts.
Another behaviour of concern is people walking dogs illegally in the national park, not only because their scents scare wildlife, but dogs tend to defecate when out walking, and much of the area is in our drinking catchment.
This sign “Your are now in the Nelson Bay drinking water catchment” is beside Marine Parade close to Shoal Bay and Fingal Bay villages.
We need to be very conscious that we live and recreate in our water catchment.
We walk, cycle, skate and take our dogs along the cycleway parallel to Marine Parade between Shoal Bay and Fingal Bay.
Immediately to the path’s east are wetlands – our groundwater – which regularly flows over the path.
Nearby sandbed catchments are at capacity
The various local catchments beyond the Tomaree catchment are at capacity.
One Mile Beach marks the southern boundary of the Tomaree catchment.
At Birubi the groundwater has now reached the carpark surface, August 2025
The groundwater level in the Tomago Sandbeds aquifer, which can provide up to 25% of the drinking water supplied to the Lower Hunter region, is similarly currently above the 100% storage level.
Photographs © Sue Olsson