Archived decisions

Contact: Tony Clatworthy, tel 01489 576387

email : [email protected]

1. Summary

1.1 The River Hamble Harbour Authority has been consulted and asked to comment on matters of navigational safety. As part of the Harbour Authority's statutory duties it has to grant consent permitting harbour works in the navigation of the River Hamble, including works to modernise, extend and relocate pontoons. This consent is in addition to the planning permission required.

2. Legal Implications

2.1 Consents may be granted by the Harbour Authority permitting harbour works under Section 10 of the Southampton Harbour Act 1924 and Section 48 of the Southampton Harbour Act 1949, as amended by the River Hamble Harbour Revision Order 1969 to 1989. Within the Harbour Authority's statutory duties lies the responsibility to ensure that all matters concerning navigational safety are addressed. This area of responsibility includes the area of the Marina at Crableck and Universal on the River Hamble, Southampton.

3. Harbour Master's Comments on Proposal

3.1 John Willment Marine Limited has applied to replace the worn out jetties and pontoons at Crableck, to modernise and reposition the layout at Universal and to carry out a capital dredge.

3.2 The proposal is to remove the existing worn-out jetties at both sites and to replace them with a more modern layout. In order to minimise any impact on the estuary the new layout is moved seawards at the Crableck end freeing a large area of intertidal mudflats from moored vessels.

3.3 A degree of capital dredging is required. The volume of this dredging is 22,000 cubic metres which is twice the amount that would be required to maintain the last Universal (north end) maintenance dredge. Due to the more seaward position of the new layout for the marina a number of existing mud berths and pontoons (that dry out) will be removed. This includes the existing houseboats that will be offered berths on the new marina. This will expose some 950 square metres of non-designated mudflat.

3.4 Following the Harbour Master's concerns that the proposed capital dredge may cause the migration of the main channel, and have effects on Bursledon Bend and Mercury Marina, the developer was requested to produce a digital modelling survey to investigate these concerns. Associated British Ports marine environmental research (ABPmer), on instruction from the developer, commissioned a survey report which confirmed the proposed dredging as having a negligible effect on the bathymetry of the River. The report concludes:

"The proposed capital dredge will not have an impact on water levels within the River Hamble and any changes in speed as a result of the scheme are small and are confined to the immediate area of the dredge and there is no significant change to flows estuary wide. Therefore, it is considered that the proposed scheme will have no significant impact on the main channel and its possible migration, although slightly more flow will be attracted towards the marina area on the ebb tide. These changes will not have any significant impact on the on-going changes at Bursledon Bend. There will be no adverse impact on Mercury Marina. The modelling indicates that any changes as a result of the scheme will remain local to the Universal and Crableck Marinas."

3.5 Notwithstanding paragraph 3.4, capital dredging in the River Hamble has been addressed as being among the Aims and Policies of the River Hamble Estuary Management Plan. See pages 50 and 52 C5 Policy 3 and pages 68 to 69 C11 of the River Hamble Estuary Management Plan (EMP). The proposed development requires capital dredging and then continuance of maintenance dredging.

3.6 The proposed new layout of pontooning does not increase the number of vessels from those already moored within the marina. The proposed development will provide the following moorings:

150 x 10 metre boats

70 x 12 metre boats

26 x 15 metre boats

2 x working berths plus various other small boat moorings for RIBs and tenders.

3.7 The following information has been included in this report as a background brief to overcome any concerns regarding the environmental consents process that is completed by other agencies and Government bodies before this proposed development will be given consent to proceed. The developer has applied for Coast Protection Act (CPA) 1949 and Food and Environmental Protection Act (FEPA) 1985 Part II licences and the Marine Consents and Environment Unit will be the competent authority to make the Appropriate Assessment in liaison with English Nature and the Environment Agency. The assessment will investigate the geomorphologic impacts to include changes to the intertidal mudflats and subtidal sediment areas, erosion of adjacent intertidal and subtidal areas and the changes in flow patterns due to dredging. The effects during construction of disturbance to over-wintering wildfowl and effects on fisheries due to raised sediment concentrations and disturbance from piling activities will also be investigated during this process. These procedures will satisfy the requirements of the Conservation (Natural Habitats & c.) Regulations 1994 and the Wildlife and Countryside Act 1981 (as amended) and provide sufficient information to advise on any impacts to the Sites of Special Scientific Interest. Fareham Borough Council will be responsible for local planning permission.

4. Risk Assessment

4.1 The Harbour Master has completed a risk assessment of the area under development and has concluded that there is no change to the current situation.

4.2 Only one observation was made by the Harbour Master which involved the loss of an access channel that might be looked on by some as a secondary channel. The access channel in question is located downstream off Crableck and inside the line of piles known as K piles. A safe secondary channel will remain between the J and K piles.

5. Harbour Master's Conclusion

5.1 The proposed development at Crableck and Universal Marina does not compromise the safety of navigation in the area

Recommendation

That, under Section 10 of the Southampton Harbour Act 1924 and Section 48 of the Southampton Harbour Act 1949, as amended by the River Hamble Harbour Revision Orders 1969 to 1989, conditional consent be granted to Universal and Crableck Marina for harbour works in the navigation of the River Hamble, permitting Universal and Crableck Marina to modernise, extend and relocate its pontooning at its moorings in the River Hamble, as shown on the Drawing No. 8686/10a and 8686/10b both drawings revised and dated C - 7 June, B - 23 March, A - 25 February 2004; also Drawing No. 8686/11 dated January 2005 which shows the 115 existing piles to be removed and the 93 new piles to be driven, and subject to the following conditions:

(i) the operator to establish and maintain at his expense, fixed double vertical navigation lights on each hammerhead, both upstream and downstream; to be established within one week of the completion of the works; and

(ii) all other appropriate consents being obtained.

9150report/TC