The Langstone Oyster Beds were restored for nature conservation in 1996 / 97. The following describes the major civil engineering project which achieved this successful restoration and led to the site’s designation as Havant Borough Council’s first Local Nature Reserve
Towards a Solution
From 1987 the Council explored various options for overcoming the problems of the Oysterbeds including letting the site to another commercial operation, passing over the ownership to the County Council (who were considering its use for oyster breeding as an adjunct to training provided at Sparsholt Agricultural College) or removal and/or improvements to the extant embankments. Unfortunately it quickly became clear that none of the proposed uses would generate sufficient income to sustain the maintenance of the embankments.
In 1990 the County Council assisted the Borough Council by investigating possible solutions for improving the amenity and safety of the site. They engaged consultants to advise on the facing, redistribution, and protection of the disintegrating embankment walls. At a time when the Council’s finances were in crisis due to problems collecting the new Community Charge, solutions offered proved to be too expensive, with some options costing in excess of £1M with no guarantee of sustainability.
In 1993 an application was made to the EEC for funding under the “Life” Programme which if successful would have seen the site reorganised, but ultimately was unsuccessful. No external assistance was available for the Borough; equally it had no funding available on the scale necessary to carry a conventional civil engineering project forward.
Public Opinion was divided. There were substantial groups in support of maintaining the status quo with the public being given access to walk on the deteriorating walls and believing that they would remain as they were with little or no maintenance. Others were as vocal in pointing out the readily apparent hazards and risks, particularly to children. Having carried out various studies and investigations it was clear by 1994 that the stage had been reached where the Councils options were limited but a choice had to be made. It was unable to maintain the site in a safe condition. It could not afford to arrange the removal of the unsuitable materials. The longer it delayed in removing the unsuitable materials the higher the costs would become as material was spread over the harbour floor. Similarly the deterioration of the walls and the spreading of the unsuitable material over the harbour mudlands made it more likely that the Council would be attacked for failing to fulfill its duties under the Habitats Directive.
As maintaining the walls was too expensive and taking no action exposed the Council to the risk of high costs either as the result of accidental injury to the public, or if it was required to remove material from the harbour, it was decided to initiate a Planning Application proposing the removal of the unsuitable material and the restoration of the site to, as far as was possible, the condition pertaining in the 1970s before the tipping took place.
Environmental Impact Assessment (EIA)
Due to the international designations in force at the site an EIA was required as input to the Planning process. Borough Councillors, mindful of the need for an environmentally acceptable solution, required that the EIA should investigate all possible alternatives, not simply the alternative proposed by the officers of the Council.
Emergency finance was found to allow Adams Hendry, Chartered Town Planners and Environmental Consultants of Winchester to be engaged in 1994 to undertake the EIA , which was completed in January 1995. Their final report advised that the prospect of the Council being required to remove the alien material from the harbour was increasingly likely as environmental legislation was strengthened and so supported the materials removal.
The publication of the EIA was used by the Council as an opportunity to hold both a Member’s seminar and a public meeting in February 1995. These meetings revealed that opinion was equally divided between three desired outcomes: to leave matters as they were; to remove the material as planned; or to have another attempt at restarting the oyster fishery as a commercial concern. Whatever course of action was taken, it appeared that two thirds of the local residents would be opposed.
The EIA found that even getting to the site would be problematic. After the material had been originally tipped in the 1980’s, subsequent development had closed the haul road used at that time. Three land routes were considered in the EIA , all having to cross the Hayling Billy Coastal Path. A northern route was ruled out due to the ecological value of the grazing marsh it would cross.
Two southern routes, with access taken from a track locally known as “Station Road”, were also identified, one direct but lying upon reclaimed land, the other less direct but partly using the route of the Coastal Path. Since there would be considerable technical difficulties in constructing a haul road capable of carrying heavy lorries over ground that was partially comprised of tipped domestic refuse, the Council adopted the route involving the construction of a temporary diversion of the bridle-way and footpath across the open land to the west of the existing bank that bounded the Hayling Billy Coastal Path.
This could be of a relatively light construction as it would only have to carry pedestrian loads and would enable the old railway embankment, which was known to be sound, to be used to carry the heavier lorries. Fencing would be provided to guide users onto the diverted Coastal Path with signs advising the public of the diversions and the reasons for the works. Risk Assessments were carried out to determine the best layout for the fencing and signs.
The only road crossing to the island, the single carriageway A3023 [Havant Road], was rated as traffic sensitive during peak hours during the winter period and all day during the summer. Lorry movements into and out of the site during peak periods would be limited to working from 1 October to 30 April each year, with positive traffic control when more than 30 vehicles an hour were using the access.
At the seaward end of “Station Road” the Hayling Billy Coastal Path ran through a car park. There were already conflicts between turning cars, cyclists, equestrians and pedestrians, and adding lorries using the haul route to this meant there was no alternative but to close the car park, although an alternative car park to the north of “Station Road” could be used.
It was envisaged that rubble removed from the embankments would be taken to a portable crusher elsewhere on the site, crushed, and stockpiled until removal. For the purposes of the planning application the crusher was specified as being portable plant of a size capable of being moved on the highway without special arrangements. The noise levels of the crushing plant and other plant would mean that such plant could only be operated between the hours of 7 a.m. and 6.30 p.m. on weekdays.
The crushing area would be surrounded by a temporary bank of material two metres above surrounding ground level in order to reduce the effects of noise from the crushing plant. The stockpiling of crushed material would be contained within this bank to act as additional noise protection. The crushing plant would then be situated partially below ground level on a platform temporarily reclaimed from one of the lagoons. Material for banks and reclamation would use some of the first material removed from the embankments.
The EIA considered habitat loss and to compensate for this some of the unrecyclable material removed from the embankments (expected to be approximately 10% of the total volume) would be placed on a small section of the former outer embankment to form a roosting island. It was noted that it would be some years before it was sufficiently stable to be fully suitable for this purpose, and in the interim the value of the site to wildlife was likely to be compromised.
In order to allow maximum flexibility for a successful contractor to identify a market for the crushed material a works duration of three winter periods (1 October to 30 April) was to be allowed.
Tenders and Contract Award
On the basis of the consultations and the content of the EIA , Planning Consent for the outline proposals to completely remove the alien material was obtained in September 1995. The Consent carried a large number of Conditions covering enabling and temporary works, programming, environmental measures relating to noise, mud and dust, aftercare and management as have been described.
For the first time the Council’s engineers now had a clear idea of exactly what would have to be incorporated into any scheme to resolve the problems at the Oysterbeds. It was now necessary to find the cost of the project to allow future budgetary provision, and it was decided on that basis to invite Tenders.
Havant has a history of carrying out works under its own Specifications and Conditions of Contract and was quite a late convert to the I CE Standard Conditions. With regard to the Oysterbeds it was considered that none of the standard Forms of Contract would meet the requirements of what was being attempted, and so documentation was drafted envisaging the award of a “quarry rights partnership” to the successful contractor. The Planning Conditions became the Conditions of Contract, these clearly setting down the hours of working and the many and various restrictions, with the expected end result of the project forming in effect a Performance Specification.
In recognition of the delicate environmental attributes of the site, non-contractual partners were invited to provide expert advice to the contractual team of Council and contractor. The project was intended to be carried out in such a way that environmental objections (in particular) could be quickly laid to rest. To this end, the project team was to be extended to include representatives from the following organisations:
- Hampshire County Council – adjacent landowners who also had a very active Countryside team managing the Coastal Path and Nature Reserves elsewhere on Hayling;
- English Nature – as the Governments statutory advisors on nature conservation officers of the Hampshire and Isle of Wight Team had been involved in evolving advice regarding the most suitable methods for carrying out the work;
- Royal Society for the Protection of Birds – adjacent owners of a large Nature Reserve in Langstone Harbour, and with expert knowledge of how birds would react to the project and how the project could encourage wildlife afteruse;
- Hampshire Wildlife Trust – managers of the Farlington Marshes Nature Reserve on the opposite shore of the harbour, again with intimate knowledge of the ecosystems and how the project would impact on them.
Invitations for expressions of interest were placed in the industry press at the end of 1995, and from the responses received a Select List of Contractors was produced taking due consideration of experience in the type of project. Preliminary meetings were held with a shortlist of four interested tenderers early in 1996 with Tender Documentation being issued to those four companies at the beginning of March, for return on 1 April 1996.
Whilst two of the group declined to submit tenders when they had seen the documentation, the others submitted tenders by the return date. Of the two, H. T. Hughes and Sons (Transport) Ltd of Fareham in Hampshire (hereafter referred to as “Hughes”, now part of the Sita Group) submitted a bid whereby the works would be carried out at no cost whatsoever to the Borough Council. After evaluation of the returned tenders, and a period of some surprise that a solution appeared achievable, a proposal was taken through the Council’s various Committees to proceed with the project rather than wait for finance to become available (this now not being necessary) and this company was duly engaged as contractor to the Borough Council during the summer of 1996.
Further Planning Consent
Some 60% of the Planning Conditions contained within the September 1995 Consent required “further information” before the contractor was able to start on site. This was not only intended to allow a successful contractor maximum flexibility in carrying out the work in a manner suitable for his own resources, but also to allow the partnership to become established “in action”. In order to satisfy the Conditions, Hughes and the Council’s engineers promoted a second Planning Application, covering the methodology by which Hughes intended to carry out the works.
Working through the summer, representatives of the Council and Hughes worked closely with the non-contractual partners and advisers and produced a comprehensive second Planning Application which was duly approved in September 1996, with further minor Conditions, allowing a start from 1 October.
Work on Site
In light of the significant environmental value of the site the Council was concerned that there was a very real possibility of action by environmental campaigners, this being around the time of Newbury. The site could hardly be more protected by environmental legislation, and some residents had been vocal in their opposition. Two critical decisions were therefore made before starting on site. The first, already described, was that the management of the project required input not only from the contractual parties but also those parties expert in matters relating to the conservation designations, thereby hopefully removing any objections on that front. The other was that the media should be fully informed of the engineering and environmental details and benefits of the project. To this end regular Press Releases were released throughout the summer informing the public of the schemes progress through the planning stage and considerable interest was shown by both local newspapers and radio stations.
When the news advising of the start on site was published, opposition was indeed mustered and for a time it did appear as though the Council was about to be faced with a “Newbury” style occupation. Fortunately nothing became of this threat and Hughes duly took access to the site on 16 October. Within two weeks the temporary works were in place, North Hayling Halt car park closed and material started to be removed from the embankments at the north of the site.
The Problems – or Challenges
It was at this point that the effect of the restrictions imposed upon the site ( SSSI status etc.) became apparent. No preliminary ground investigation had been carried out since to even take the simplest mechanical plant onto the site would have required the installation of all the temporary works, diversions and closures. All parties had made assumptions (in good faith) but the material now being removed from the first embankment at the northern extremity of the site was significantly different in composition from that expected from the hearsay records of the time.
Instead of an embankment of “pure” rubble tipped cleanly onto the Victorian shingle remains, what was actually on site was a combination of two effects. Firstly, the rubble originally must have had a high proportion of soil within it, which in places had formed into an inner soil core within the embankment. Secondly, the underlying shingle had deformed over the years of burial and had migrated up into the body of the embankment. The result was that the original intention of cleanly removing all the tipped material and leaving the underlying Victorian shingle banks scraped clean, could not be achieved.
Of immediate concern was that material with which to reclaim the temporary working platform upon which to place the crusher was unsuitable for that purpose. A rapid reassessment of layout of this part of the site by the Project Team led to a decision to rotate the crusher’s orientation through 90 degrees so that instead of being wholly on the platform it could now be placed on what was the original shoreline embankment. This was composed of chalk over 60 years old and was firm enough to allow a shelf to be excavated from it to achieve the required lower elevation of the crusher as required by the Planning Conditions. The reclaimed platform would now be used solely for stockpiling crushed material ready for removal from the site.
Less immediate but potentially more serious was the effect on the economics of the project for the contractor. It was more difficult to him to remove material from the embankments, and of course a lower proportion than expected was of recyclable quality which would lower the overall income from the project. The originally expected 10% unrecyclable portion was now expected to reach 50%, or 50,000 tonnes.
Since the contractor now had complete access to the site it was agreed to carry out a programme of trial holes within the various embankments. This led to the surprising discovery that although from the outside all the embankments looked the same, under some a substantial core of rock chalk was intact, whilst within the sheltered northern lagoons embankments were composed almost exclusively of clay soils of varying quality.
The Project Team quickly realised that the chalk embankments could be left in situ once the surface covering of rubble had been cleared, and likewise the clay since its erosion would cause no damage to the harbour environment, and might in fact provide useful material to feed the surrounding mudflats.
In theory therefore a solution to the challenge which had arisen had been found. Although the expected income from the project had reduced, so too had the amount of work. The contractor volunteered to continue on a basis of no net cost to either party, and it is to his credit that he did not walk away from the site but worked hard with all the parties to secure a successful outcome. This attitude was no doubt partly due to the high level of public interest in the project but reflected a commendable commitment both to the contract and to the environment.
However matters are never so simple as they first appear. Incorporating the changes suggested above would be a significant departure from the scheme for which Planning Permission had been given (twice) and it was not just a Council decision – being within the SSSI the full list of consultees would have to give their approval.
It was now that the management arrangements for the project paid dividends. The involvement of English Nature, the RSPB , and the Hampshire Wildlife Trust on the project management team meant the resolution of the problem was developed in the presence and with the input of the major parties to the planning consultation process. In fact this presented an opportunity whereby those non-contractual partners could meet some of their aspirations for the site which perhaps the original proposals would have not met. Therefore the revised arrangements for clearing the site (which were still driven primarily by safety concerns) could now, by “taking advantage of the contractors presence”, include significant improvements to the habitats at the site.
As an example, the original plans would have seen all the embankments removed and the unrecyclable material used to recreate within one of the by then tidal lagoons, a roosting island. It would have been perhaps two or three years before vegetation had colonised the island for it to be of significant benefit to wildlife. In the new arrangements some existing embankments would be severed at their landward end with minimum disturbance to the vegetation and so would remain available uninterrupted.
Planning Permission was obtained for the third time for the changes, and works now progressed in the main according to plan. The reduced amount of material to be removed, and the eagerness of the contractor to reduce the time plant was on site, meant that the project was substantially completed on 23 May 1997, only seven months after starting; in itself a major local media event with coverage by the local newspaper and BBC and Independent Local Radio.
The final quality of surface finish to the embankments was very good considering the circumstances. Although the underlying Victorian embankments were only exposed in a very limited number of places, the Council had successfully achieved its objective of removing the dangers from the site, leaving in their place embankments which would be formed into sustainable profiles by the action of wind and wave.
The embankments have now been exposed to some severe weather events over the past few years including an exceptional event on 10th February 1997 which completed a civil engineering task scheduled to last three weeks, in 1½ hours. This profiling by natural forces has resulted in a textbook storm beach forming on the outer [harbour] edge of the embankments, with finer material overtopping and covering the more blocky material beneath. This new profile has provided excellent roosting facilities for wildlife which it was feared would be displaced from the site, with the result that overall seabird numbers are up 20% on the numbers prevailing before the work started.