Technical Services (Engineering) Division overview approved by Cabinet Member responsible for Sustaining Our Environment.

1. General
2. Land Drainage
3. Coast Protection
4. Cliff Management
5. Summary

1. General

Bournemouth Borough Council is the Land Drainage Authority for its administrative area and is responsible for the management of the following Ordinary Watercourses:

• The Bourne Stream Partnership
• The three tributaries and the main course of the Kinson Stream, including the flood alleviation dam above Kinson Primary School
• Various minor watercourses such as the Cudnell Stream, the Alum Chine brook, the High Howe stream, ditches around the Mallard Road/Bradpole Road area and ditches in the Northbourne/Redhill area.

Bournemouth B.C. is at present responsible for flood management of the above mentioned streams. The Statutory Main River and its tributaries within the floodplain of the Dorset River Stour are the responsibility of the Environment Agency. Consequently the resolution of any flooding problems of the Mobile Home Parks at Northbourne, Redhill and Iford Bridge lies with the Environment Agency. The Council is represented by an elected Member on the Avon and Dorset Local Flood Defence Committee that manages flood defence issues in the South Wessex Area. The Land Drainage Act, 1991 Section 14(2) prevents the Council from undertaking any works in connection with a Statutory Main River.

Bournemouth B.C. is the Operating Authority for Coastal Defence management under the auspices of the Environment Agency, to whom the Council has to report annually on its performance management in conjunction with the Regional Coastal Group, the Standing Conference on Problems Associated with the Coastline (SCOPAC). The Council is required to submit regular returns to the Central Government Department charged with the responsibility for flood and coastal defence issues, the Department for Environment, Food and Rural Affairs (DEFRA).

Bournemouth B.C is a Funding Member of the Regional Coastal Zone Management Group, the Dorset Coast Forum, that provides the overview on the planning issues associated with the coastal zone, many of which do not respect local authority boundaries and have to be managed on a inter-authority basis, such as bathing water quality, coastal pollution, recreational issues.

Bournemouth B.C. is a member of the Standing Conference on Exploration for Oil and Gas in the English Channel, which is largely focussed on oil and gas issues off the Hampshire and Dorset Coasts.

2. Land Drainage

The Government has undertaken a fundamental review of flood defence issues and has recently announced some changes that may possibly impact upon some of the Council’s activities, and these are :-

• The removal from Council responsibility of the Critical Length of the Ordinary Watercourse (CROW) of the Kinson Stream – the length that is capable of causing flooding, and that is the section downstream of the flood alleviation dam. The responsibility may pass to the Environment Agency.
• The disbandment of the Avon and Dorset Local Flood Defence Committee, its role being replaced by a single tier responsibility yet to be decided by the Wessex Regional Flood Defence Committee. (An alternative proposal has been approved by the Council and forwarded to the Agency that would create a combined single tier structure based upon Avon and Dorset, as well as Hampshire and the Isle of Wight).

The Council is a member of the Bourne Stream Partnership, a funded group of organisations involving Bournemouth B.C and Poole B.C. that is tackling the water quality problems of the Bourne Stream along its entire length from its three sources in Poole, to the discharge points in the sea off the bathing beach at Bournemouth Pier. The Partnership includes the Environment Agency, Wessex Water and Bournemouth and West Hampshire Water Company and has funding sufficient to provide a project officer progressing water related issues in the catchment of the Bourne Stream. One of the key objectives of the Partnership is to reduce the level of first flush pollution in the Stream following rainfall to ensure the award of a prestigious Blue Flag at Bournemouth Pier.

Whilst not having the first responsibility for flood protection of properties within the flood plain of the River Stour, the Council has identified 14 key sites where there is an increased risk of flooding and also several sites where flood evacuation of residents has to be provided for. The Council is required under the DEFRA High Level Targets for Flood Defence to produce a Plan for Flooding, the draft of which has been produced and is currently at the second consultation stage. The final version is to be distributed to the Emergency Services and the Environment Agency as well as within the Council. It will be a controlled document under the Data Protection Act since it identifies individuals at risk.

The Council has been working with the Environment Agency in order to determine the worthwhileness of possible flood alleviation schemes for the following sites that have a history of river flooding :

1. Longham Bridge, Ringwood Road and Millhams Road;
2. Stour Park Mobile Home Park;
3. Redhill, Wheatplot and Kingfisher Mobile Home Parks;
4. Iford Bridge Mobile Home Park.

At the present time, none of the mobile home park sites meet the Government’s economic criteria set by the H.M. Treasury for the use of public funding of flood defences. The Council has indicated that it would be willing to assist residents at Iford Bridge Mobile Park, who are pursuing a policy of self-build flood defences, with scrap kerb stones and off-cuts of hardwood timber from groyne construction works. In addition, some residents have already funded themselves the raising of their properties to 1 in 20 year flood levels as advised by the Agency in order to secure buildings insurance cover.

3. Coast Protection

Bournemouth B.C. currently operates coast protection policies established after many years of practical experience and maintenance, following close collaboration with the Government’s research organisation, the Hydraulics Research Station, now operating in the private sector as H R Wallingford Limited.  DEFRA (previously the Ministry of Agriculture, Fisheries and Food (MAFF)) have grant-aided the Council’s programmes of coast protection works as follows :

• Beach renourishment and primarily hardwood timber groynes along the formal man-made coastline between the Boundary with Poole and the end of the Promenade at Point House Cafe, Southbourne.
• Beach renourishment, timber and rock groynes along the natural coastline between Point House Cafe and Double Dykes.
• Managed retreat with maintenance of the beach width (limited intervention) using beach renourishment using shingle between Double Dykes and the Hengistbury Head Long Groyne.
• Rock groynes and revetment between the Long Groyne and the root of the Mudeford Sandbank, including rock armour to the Long Groyne itself.

The Council’s policies were re-affirmed in the consultation and production process that formulated the Shoreline Management Plan (SMP) for Poole and Christchurch Bays. The SMP was adopted by the Council as part of the requirement of MAFF who grant-aided the work undertaken by the Council’s consultants, Halcrow Maritime. The Council acted as Lead Authority for this work on behalf of Purbeck D.C., Poole B.C., Christchurch B.C. and New Forest D.C. The Management Group included representatives from Dorset C.C. and Hampshire C.C., Poole Harbour Commissioners, English Nature and the Environment Agency.

The DEFRA High Level Targets for Flood and Coastal Defence require the Council to produce a Statement of the Council’s Policies and this was produced in February, 2001. This Statement is currently being revised and a draft is in preparation for Cabinet consideration and approval, following the outcome of the present Strategy Studies for Poole Bay and Harbour.

The SMP had highlighted areas requiring further and more detailed studies and the DEFRA grant-aided Strategic Studies are now at the completion stage, ready for presentation to the general public, stakeholders and elected Members in the three Councils involved in the preparation. Revisions in National Flood and Coastal Defence policies driven by the impacts of flooding in the latter part of 1999 have had to be included in the Strategic Studies, primarily the impacts of global warming, sea level rise and increased storminess.

Accordingly, predictions of the state of the future coastline as a reaction to the above mentioned changes in climate have lead to revisions in the future coast protection policies necessary to protect the Bournemouth coastline. In optimising the most economic solutions for the future coast protection of the coastline, alternative defences have been examined and costed, together with an assessment of the level of benefits if such defences were to be implemented. The consultant was asked to examine the use of conventional coast protection measures as well as innovative systems such as patented artificial reefs whose World-wide licencing arrangements are held by Professor Kerry Black.

The needs for extensive consultation have been overcome by the consultant already consulting the 140 organisations that have responded to the initial consultation process, these mainly represent the specialist interest groups with environmental interests or extensive users of the marine environment in sports and recreation fields.

The previous SMP consultations have involved the following activities :

• Production of a colour leaflet distributed to Seafront Information Centres, Public Libraries and relevant Council Departments
• Public Exhibitions held at appropriate venues with full access for disabled persons, with the Consultants present to explain their findings to interested parties
• Presentations to Council Members in adjoining Towns by the Consultants
• Presentations to the specialist interest groups by the Consultants.

4. Cliff Management

The Council had previously adopted the report of the Borough Engineer and Surveyor entitled "Stability of the Bournemouth Cliffs – between Borough Boundary with Poole and Solent Beach, Hengistbury Head – Situation in Spring, 1991" that set out a programme of cliff management and stabilisation works to be undertaken along the length of the coastal cliffs in Bournemouth, focussing on those areas providing the highest risk of cliff falls and where the Council was proposing seafront development of sites proving to be of commercial interest.

The programme of works came to a halt in 1991 with the conclusion of the programme of installing vertical sand drains along the length of the East Overcliff Drive on the East Cliff up to the western approach to Boscombe Pier. Apart from isolated local cliff slippages and mud slides, no major cliff falls had taken place along the length of the Bournemouth Cliffs in the period 1991 – 2000. However, following a period of exceptional rainfall in autumn and winter of 2000/2001, loose and unstable material, weakened as a result of the continuous driving rain, fell from cliff slopes beneath the Highcliff Hotel, west of the West Cliff cliff lift. The cliff fall revealed three levels of groundwater flow and the fallen material, as well as the accumulated saturated cliff material required the removal of beach huts at Promenade level for safety reasons.

Initial remedial works included the installation of 35m deep vertical sand drains around the northern edge of the slipped area, surface water drainage repairs and installation of cliff movement monitoring equipment. The effect of the vertical sand drains has been to control groundwater and gradually dry out the active cliff slip zone, thus stabilizing the previous mobile mud, sand and gravel.

Whilst the Council chose to implement the necessary remedial cliff works, it also decided not to take the opportunity to update the previous Cliff Stability Report dated 1991, especially as seafront development had already taken place at Promenade level beneath unstablised cliffs and in front of old retaining walls supporting the base of such cliffs. Ad-hoc redevelopment had been implemented without the benefit of a comprehensive review of the Victorian and Edwardian walls, particularly on the West Undercliff Promenade.

At the moment the following key areas have cliff instability or retaining wall issues :

• the West Undercliff Promenade from the Aquarium to the western extent of the West Beach Bathing Station, now known as Happylands.
• the Boscombe Cliffs, east of Honeycombe Chine up to Manor Bay

5. Summary

The Council may possibly pass the responsibility for management of the Critical Section of the Ordinary Watercourse known as the Kinson Stream to the Environment Agency.

The Council will be producing its Local Plan for Flooding under the DEFRA High Level Targets.

The Council, if required, will be providing assistance to owners of properties within the Iford Bridge Home Park who are proposing to self build their own low cost flood defences.

The Council will be losing representation on the Avon and Dorset Local Flood Defence Committee, but may gain representation on a new single tier flood defence committee.

The Council will maintain its membership of the following groups :

• The Standing Conference on Problems Associated with the Coastline (SCOPAC)
• The Dorset Coast Forum
• The Standing Conference on Oil and Gas Exploration in the English Channel
• The Bourne Stream Partnership

The Council will conduct appropriate consultation in connection with the publication of the findings of the Strategic Studies undertaken in connection with the Shoreline Management Plan for Poole and Christchurch Bays.

The Council’s consultants have given a presentation of their findings to Council’s Scrutiny Panel for Safeguarding Our Environment.

The Council’s existing programme of timber groyne rebuilding and beach renourishment is ongoing.  With the coast protection policies for the Bournemouth coastline being subject to the recommendations of the SMP Strategy Studies as adopted by the Council.

The Council will be producing a revised Statement of its Coast Protection policies following the adoption of the Strategic Studies recommendations.

The Council will need to make financial provision for and undertake a comprehensive review of the stability of the Bournemouth Cliffs and associated cliff retaining walls since the last update of the situation was undertaken in 1991.