Threat to Portsmouth Harbour– Summary 2023 – Updated January 2024
In the autumn of 2022, the King’s Harbour Master reported shoals close to Portsmouth Harbour entrance. In early 2023, a brief was forwarded to the Minister, drawing attention to the dangers, particularly regarding the proposed remedial dredging to clear these obstructions from the entrance channel. The Minister did not appear concerned but locally some questions were being asked and, in late March, it was at Gosport that a well-received presentation was given to a full council meeting.
In mid-summer the long-term DIO (Defence Infrastructure Organisation) report into the future repair of the Blockhouse part of the wall (now known as the Jacobs Report) was due to complete. In draft form, at least, it probably finished on time, remaining ‘in house’ as the MOD sought to prepare suitable costed options; the aim still, at this stage, being to sell the estate, together with future wall maintenance liability.
It is probably no coincidence that, in early August, a licence application was made for serious sea-defence work at Blockhouse; a licence still not granted when the process came to light in October. A further brief was prepared and issued on 3 November ‘Blockhouse Nov 23‘, coincidentally the day after Storm Ciaran caused significant damage. A photograph taken from seaward shortly afterwards showed a large hole underneath the radar mast – see ‘Blockhouse Wall, Radar Mast Hole‘.
A particularly positive factor, post storm, has been the decision by MOD/DIO to issue statements regarding progress of remedial work. Perhaps a little short on detail, these have been really useful, highlighting the very significant efforts being made within the establishment to contain the damage.
In mid-November, the MOD reported that plans to dispose of the site would be temporarily paused while repairs were carried out. The full extent of the damage – whether from the storm or the earlier ‘licence application’ work, remains unclear to external observers. On 28 Nov, DIO reported completion of successful repair work – ‘to fill and secure the voids created by the storm’ – on the damaged sea wall close to the Signal Tower at the harbour entrance. On 3 Dec, a month after the storm, repair delays allowed expansion of the ‘radar hole’ causing undermining and closure of the adjacent main access road.
It is these delays, seemingly outside the control of the establishment, which will be increasing repair time, costs, and future risk. Given the importance of the site – no sea wall = no aircraft carrier base-port – a further brief was issued on 18 December ‘Blockhouse Repairs Dec 23‘. Thus we come full circle and, with a new Minister in place, hope that, this time, the opportunity might be taken to address the issues.
CHD 5 Jan 2024
Haslar Wall by Chris Donnithorne
Chris Donnithorne has written a further report: ‘Haslar Wall’ (January 2022) with the accompanying statement:
In December 2021, an apparently sound part of Haslar Wall was damaged by storm ‘Barra’, with the manner of failure looking remarkably similar to such events at Blockhouse. The full extent of the wall had not been considered before, for reasons stated in the original paper. This brief, produced as a result, and clearly directing attention to this aspect of the threat, was made available locally and subsequently to attendees of a meeting convened to consider such issues.
Caroline Dinenage (Gosport MP) – already briefed that wall failure here would become a national issue – chaired the meeting of interested agencies, national and local, and myself, on 28th January 2022. The agency attendees provided positive reports of their various activities regarding the wall and, in summary, assured the Chair that the harbour entrance was secure, there was no flood risk, and new owners could be expected to fund this sea defence into the future – to which the Chair announced that she was encouraged by all that she had heard. The wall issue now appears dead until the next big storm damage.
1 February 2022
Update to the Threat to Portsmouth Harbour
Chris Donnithorne, a former naval officer, has updated his paper which raises urgent concerns about the immediate and future viability of Portsmouth Harbour. The NDS publishes it for public information and debate.
Portsmouth Harbour is an amalgam of natural and manmade events, originating when rising sea levels drowned the coastal plain after the last Ice Age. Its entrance has been kept clear by a scouring ‘double high tide’ and the influx of river water from the South Downs, but it has required occasional dredging at the harbour mouth to reduce the silt bar. With its creeks, streams and mudbanks, the harbour is a complex organism which is showing identifiable signs of stress.
See the update here See more about the original paper and also Chris Donnithorne, below.
Dr Ann Coats
30 November 2020 (brought up to date 20 December 2020, with the update added 6 December 2021)
Chris Donnithorne
Over a 30 year career as a naval officer, Chris Donnithorne became very familiar with Portsmouth Harbour, and he has subsequently spent as much time again carrying out archival research in the local area.
In this carefully argued and evidenced paper, Donnithorne demonstrates that the integrity of Blockhouse Point on the western side of the harbour entrance is ‘at risk due to rapid acceleration in seashore erosion, almost certainly caused by recent dredging, which included a significant part of Hamilton Bank, immediately to the South of the Fort.’ (p. 29). Effectively the dredging has destabilised the harbour entrance, leading potentially to the loss of the deep-water harbour.
19 December 2020
Naval Dockyards Society 