At the time of writing Thanet District Council are proposing opening up the sluice in Margate Harbour to flush out the harbour silt.
In volume nine number two of bygone Margate published by the Margate Historical Society there is an article by Mick Twyman called piering into the past. It covers the issue of the sluice in Margate harbour, and it reads as follows.
In an effort to flush out the Harbour in order to stop it silting up, it was decided to open up a sluice under the wall in the form of an arch 9 feet wide and 9 feet high, the sides being 6 feet to the spring of the arch, and paved at the bottom to also act as a cart road for the removal of silt, this method being quoted as costing only sixpence per ton as to the two shillings per ton cost of filling the lighter by hand for discharge at sea. Nowadays, only a few feet of this arch show, even on the outer wall of the pier, which illustrates just how much levels have risen over the intervening years, but even then the level in the Harbour was six feet higher than that outside. the reasons given for this accumulation were, just as those given today, quite spurious, ranging from the seaweed driven in by gales rotting to make the silt, or the sand churned up by steamboats settling in the wrong place. In fact, one of the proposals once the sluice was built was to station a steamboat stern to it and let the wash from her paddles turn out the silt through the wall
What had in fact caused a rapid worsening of the problem , started initially by the same continuous eastward drift of sand which we still experience today , was the construction of the stone groyne at the Nayland Rock, a project paid by the Company as an experiment to retain sand in the bay which believe it or not , had a lot of shingle in it at the time. Well now they knew the answer and just look at the state of the bay when it will soon be possible to walk from the Clock Tower to the Harbour Slip and only get wet up as far as the knees. This experiment with the sluice cost the Pier & Harbour Co. around 853 pounds, and the project was a failure. After all, how could a tunnel pointing in the direction it did have any effect on clearing detritus and silt from along the wall? In the event, all it did to cause a great agitation of water inside the harbour in rough weather, and almost certainly brought in more sand than it let out.