The Marine Notice has been issued to inform boaters that there will be Navigation Restriction during dredging operation which will take place from Monday 7 October until Wednesday 20 November 2019.
See official Notice here https://www.rms.nsw.gov.au/…/so1948-entrance-bar-to-the-cly…
As always vessel owners should operate their vessel with caution when in the vicinity. It is expected that the dredging pipe will be in place for the duration of the dredge while the barge may only be in place during daylight hours – same as last time in 2016 and in 2012.
The notice state: “Vessel operators should continue using the Clyde River Bar Leads as an aid to navigation when crossing the bar.” The Association has been pushing as hard as we can to get a Notice to Mariners posted when the leads are moved because they do not indicate the best passage over the bar and you adjust but when they move them you dont know and you run aground. Currently they are well outside the area they should be on the Australian AUS 191 chart but that is a technical issue which skilled Mariners would only notice. See Photo in 2016 when they indicate the channel way to the north then last month when they indicate the channel way to the south.
It appears that unlike the last time the bar was dredged the current dredged sand (spoils) will be reintroduced into the water in the area of the isolated danger mark – right in the middle of the Bay. Why there you may ask? There has not been a single digital or physical model undertaken by any organisation as to the sand movement within the bay. There is the diagram drawn for the BB Coastline Hazard Management Plan in 1997 from the original Patterson Britton & Partners 1992 document. See below. While indicative it may not be correct.
This clearly shows that when the dredged sand come out of the dredging pipe next week they will move towards the north west beach area of Surfside or more likely back out into the bay and again be deposited on the bar or in the bay off Corrigan’s Beach.
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| 2016 sand deposited before removal to Surfside |
How does the Association or in fact anyone else know this? We dont. It is all speculation and even with the local knowledge base of the Association members we can not predict what will happen. So how can this happen in this day and age of GHD modelling of the impact of civil works on the northern Surfside beaches and elsewhere in the Bay. Do I have to state the obvious – vested interests have again come into play to try and prop-up the desire by politicians and bureaucrats to just be seen to do something.
See the Critical Analysis post GHD Study
Members of the Association have been calling along with many others for a scientific study to be undertaken on the movement of sand within the bay and this to feed into a benefit cost analysis of when, why and where dredging should take place if at all.
With the new bridge under construction and the flood and flow analysis so under a cloud why would anyone sign-off on dredging the bar and then adding that sand back into the bay thus confusing any previous analysis. It is just madness.
