As most Tasman residents would know, on the weekend of 9 and 10 July an out of the ordinary storm event occurred across southern Tasmania. As well as causing damage across the region, there was a direct and quite damaging impact on the Port Arthur Historic Site.
The combination of extremely high tides at approximately 3.00 pm on both days, high wind activity, and extreme surging in the bay resulted in waves breaking over the sea wall around the perimeter of Masons Cove, and Radcliffe Creek being prevented from discharging into the Cove. The water movement up Radcliffe Creek was substantial, compounded by the creek carrying an additional flow of water from rain activity.
Most of the damage was caused on Saturday and for safety reasons the whole waterfront area of the site was closed to visitors. The sea wall suffered substantial damage, as did most of the paths along the waterfront.
A number of blocks from the Commandant’s jetty were dislodged and moved. Two of the three concrete-footed benches on the water front were moved several metres, and PAHSMA staff relocated the guard box in front of the Penitentiary before it could be washed away.
The Penitentiary itself was totally inundated, with water lapping just below the level of the ground floor boardwalk. The outside was subject to scouring from the waves and debris, with salt-infestation now a matter to be dealt with. The Watchman’s Quarters were underwater to just above the floorboards.
The damage extended to infrastructure, and the Isle of the Dead was closed due to damage to the jetty.
The Garden Point jetty was also temporarily closed, but is now re-opened with some further work to be done in the next few weeks. PAHSMA staff are working on repairs to the boat ramp at Garden Point, but this could be closed until mid-August.
The loss of two privately owned jetties at Carnarvon Bay is testimony to the damaging wave action across that beach, and severe erosion at the base of a number of large trees required the temporary closure of the beach while a formal safety assessment was undertaken.
The beach has been re-opened with the approval from a tree expert. However the roots are now exposed to sun and air, and there needs to be a blanket of sand re-deposited over the exposed roots in order to protect them from drying out and dying. This work will be done in the next few weeks.
If any residents have queries about the damage and ongoing works please contact Jane Harrington at the Site on 6251 2330.