Flood alleviation improvements from Acle to Great Yarmouth (Compartment 11 Bure) Public Consultation July 2007

Transcription

1 Introduction PROTECTING BROADLAND Flood alleviation improvements from Acle to Great Yarmouth (Compartment 11 Bure) Public Consultation July 2007 In May 2001 Broadland Environmental Services Limited (BESL) was awarded a long-term contract by the Environment Agency to improve and maintain flood defences in Broadland. The Agency s approach to flood alleviation in Broadland was adopted in the 1990 s and is based on a strategy consisting mainly of bank strengthening and erosion protection in order to reduce the risk of banks breaching. BESL updated this strategy and is now carrying out improvement works throughout 40 individual flood compartments in Broadland. The major improvement works will be undertaken during the first 10 years of the Project; thereafter the banks will be subject to regular condition monitoring and maintenance works as required. Consultation This leaflet has been prepared as part of an ongoing process of consultation to inform you about BESL s proposals and to seek your views on them. The purpose of this consultation document is to: Explain the range of flood defence options that BESL can consider; Outline our preferred flood defence proposals at this stage; Invite your views on these proposals; and Ensure, from the responses we receive, that we are aware of any specific local issues that ought to be considered as we go on to develop the proposals in greater detail. BESL will carefully consider any comments it receives, seeking clarification and incorporating changes where necessary before finalising its plans. The results of this consultation will play an important part in BESL s planning application for the proposals. Feedback from this consultation will be contained in the planning application documents. A questionnaire is provided with this leaflet. If you have not received one, or if you would like an electronic copy of the questionnaire by , please contact Angela Rowe at the address given at the end of this document. Alternatively, all consultation documents produced by BESL can be downloaded from the BFAP project website ( Mooring on the River Bure Six Mile House Drainage Mill River frontage Broadland Environmental Services Limited Working in partnership

2 Site description Compartment 11 Bure is located on the right bank of the River Bure from Acle boat dyke to Great Yarmouth including the south bank of Acle Dyke. The site is currently protected by 15.8km of floodbank, with reed rond and a significant amount of piling providing erosion protection. The area is mainly used for grazing and arable purposes but also contains residential properties, businesses and recreational facilities as well as the A47 trunk road and the Norwich to Great Yarmouth railway line. A public footpath runs along the top of the floodbank for the entire length of the compartment. There are no formal moorings located in the compartment, but informal moorings exist at the Pontiac Diner and Stracey Arms Mill, private mooring is located in Acle boat dyke. Need to improve existing flood defences The standard of the flood defences in Broadland has progressively reduced over time due to bank settlement and the combined effects of erosion and deterioration of piling. Tunstall, Calthorpe and South Walsham marshes are currently defended by floodbanks, sheet steel and timber piling. BESL aims to minimize the risk of breach through a combination of strengthening or setback of the banks and repiling and improving the erosion protection. A length of existing soke dyke What options did BESL consider from improvement works in this compartment? The range of flood alleviation solutions that BESL considered for these works follows the Environment Agency s and BESL s overall strategy for flood alleviation in Broadland. Specific solutions are based on up-todate survey data (assessing the condition of the existing floodbank and erosion protection), an evaluation of the level of flood defence provided and local issues including environmental considerations. The options BESL have considered are illustrated and explained in the enclosed flyer. A brief outline of some of the decision criteria leading to a particular option as the preferred solution is also given. What are BESL s specific proposals for Compartment 11 Bure? A summary of these works is as follows: Proposed works Maintain 1196 Maintain and install piling 223 Maintain and install erosion protection 77 Strengthen 7634 Strengthen and install piling 893 Strengthen and install erosion protection 241 Strengthen and maintain erosion protection 424 Rollback 3229 Setback 970 Setback and remove piles 894 A plan of the proposed works is included with this leaflet. The primary aim is to provide defences that will resist breach in the event of a high level flood event occurring, such as that which occurred on November 1st The levels will be raised in places, but not to an extent that will prevent over-topping as it is important that the improvements will not result in a change in flooding patterns at nearby locations. Material will be sourced from the soke dykes. Where the existing dyke is considered to be too close to the existing floodbank, and therefore has the potential to make the bank unstable, this will be filled and a new, wider soke dyke will be excavated. Where the soke dyke is at a suitable distance from the floodbank the existing dyke will be widened on the marsh side to provide material for the bank works. Alternatives BESL considered and discounted Length (m) The aim of these works is to strengthen and, in places, raise the level of the existing defences so that they will not breach in the event of a high level flood event. Where the existing erosion protection is failing (e.g. piling is in poor condition or the erosion protection has deteriorated), setback is usually the preferred option. The do minimum alternative would involve maintenance only to both the floodbank and existing erosion protection. However, parts of the existing floodbanks do not provide the level of protection required, as they are too low or have poor erosion protection. If the proposed works are not undertaken, there would be an increased risk of overtopping and a greater likelihood of breach. BESL and the Environment Agency do not consider the consequence of this alternative acceptable.

3 Will the proposals have any impacts on flora, fauna and designated sites? What changes to the local landscape will the work cause and how will historic built structures be protected? To what extent will the proposed work affect navigation? What impacts will there be on other informal recreation? What are the implications for landowners and business as a result of the proposed improvement works? What other flood defence works are planned for this part of the Bure? What is the proposed timing of these works? Surveys for water voles, otters, bats, reptiles, scarce plants and dyke vegetation have been undertaken to identify measures that need to be taken to avoid or minimise impacts during construction. There will be a slight loss of grazing marsh but increases in rond and soke dyke habitat following construction. Full details of the proposed mitigation measures will be provided in the Environmental Statement that will be submitted with the planning application. Hydraulic modelling results have informed what solutions can be used without increasing the amount of saline intrusion further up the system. A number of changes to the view across the landscape are anticipated as a result of the proposed works notably where setback banks are built. However, the majority of changes are temporary, such as the view of bare ground until vegetation re-establishes on the floodbank, folding and within the soke dykes. Five historic mills are located within the compartment. BESL will follow the Project s Protection of Built Heritage Mitigation Practice Note when designing and implementing solutions close to these structures. Completion of the flood alleviation works will provide long-term protection of the Broads landscape and from the damaging effects of flooding. The majority of the construction works will be carried out from land. Waterbased work such as re-piling and other erosion protection will be completed in the winter months. There is a public footpath on the floodbank that runs the entire length of the compartment. The footpath will need to be closed temporarily whilst the works are in progress. Where possible an alternative route will be provided at the upstream end of the compartment from Tunstall Dyke to Stracey Arms Drainage Mill. Upon completion of the works in this area the path will be reinstated along the crest of the floodbank. During the works there will be some loss of land for grazing and access. BESL contact landowners early in the design process to ensure their views are taken into account. There will be a small net loss of grazing and arable fields for which compensation payments will be made. Early consultation is ongoing with businesses in the works area so that disruption can be minimized. Works are already underway in Compartment 10 (Stokesby and Mautby) on the opposite side of the river. It is expected that these will be completed in Looking across a reed rond towards Old Hall Drainage Mill

4 What are the potential issues associated with this work? The Strategic Environmental Framework (SEF) process, developed by BESL with extensive stakeholder input, sets out environmental standards for maintenance, flood defence improvements and first-time defences for undefended communities. The scheme details are consistent with these environmental standards. The table on the previous page identifies some of the key issues associated with these proposals. We would welcome your comments on these and any other issues that you think should be included. What is the proposed timing of the works? A planning application will be submitted in autumn 2007 with a view to the river based works beginning winter 2007 and main construction earthworks in spring It is expected that the works will be completed in Vegetation clearance will be required in winter 2007/2008. What are the next steps? Thank you for taking the time to read through this information leaflet and answering the associated questions in the accompanying questionnaire. BESL is keen to find out what you think of these proposals. We will collate your replies and consider all comments made; these will help to inform us as we develop the proposals in more detail. If you have any queries regarding either these proposals, or those elsewhere in Broadland, please phone Angela Rowe (BESL Project Administrator) on: Concrete wall defences Contact us If you wish to reply we would encourage you to your response to Angela Rowe at: Halcrow@edmund-nuttall.co.uk Please mark the subject line of your with: Compartment 11 Bure Consultation Alternatively, our freepost address is: Broadland Environmental Services Limited Freepost ANG20504 Norwich NR1 1ZW Both the consultation document and accompanying questionnaire can be downloaded from the project website at: BESL would like to reduce the amount of paper we consume. In future can we you notification of the consultation documentation being on the web? If you are happy for us to do this please confirm, via , the best address for us to send the notification to. Please try to ensure that all replies are received by: 22nd August 2007 Replies can be considered after this date but please contact us first if you need an extension. List of consultees In addition to landowners/residents we will contact: Acle Parish Council British Dragonfly Society Broads Angling Strategy Group Broads Authority Broads IDB Broads Hire Boat Federation Broads Society CPRE Environment Agency Great Yarmouth Borough Council Halvergate Parish Council Mautby Parish Council National Association of Boat Owners Natural England Norfolk and Suffolk Boating Association Norfolk Anglers Conservation Association Norfolk Area Ramblers Norfolk County Council Norfolk Landscape Archaeology Norfolk Wildlife Trust Norfolk Windmills Trust Open Spaces Society Reed and Sedge Cutters Association RSPB Stokesby and Herringby Parish Council

5 Plan of the entire project

6 Plan of the project ³ Damgate Marshes, Acle Decoy Carr, Acle Legend Extent of Flood Compartment Proposed Works Sites of Special Scientific Interest Maintain Maintain & install sheet piling Maintain & install erosion protection Strengthen Strengthen & install sheet piling ,000 Metres This map is reproduced from Ordnance Survey material by Halcrow on behalf of the Environment Agency with the permission of the Controller of Her Majesty's Stationery Office. Crown Copyright. Unauthorised reproduction infringes Crown copyright and may lead to prosecution of civil proceedings. Licence Number GD03177G Strengthen & install erosion protection Strengthen & maintain erosion protection Setback Rollback Halvergate Marshes Setback & remove piles Flood Defence Proposals for Acle to Great Yarmouth (Compartment Number 11 River Bure )

7 Plan of the project ³ Legend Extent of Flood Compartment Proposed Works Sites of Special Scientific Interest Maintain Maintain & install sheet piling Maintain & install erosion protection Strengthen Strengthen & install sheet piling ,000 Metres This map is reproduced from Ordnance Survey material by Halcrow on behalf of the Environment Agency with the permission of the Controller of Her Majesty's Stationery Office. Crown Copyright. Unauthorised reproduction infringes Crown copyright and may lead to prosecution of civil proceedings. Licence Number GD03177G Strengthen & install erosion protection Strengthen & maintain erosion protection Setback Rollback Setback & remove piles Flood Defence Proposals for Acle to Great Yarmouth (Compartment Number 11 River Bure )

8 Plan of the project ³ Legend Extent of Flood Compartment Proposed Works Sites of Special Scientific Interest Maintain Maintain & install sheet piling Maintain & install erosion protection Strengthen Strengthen & install sheet piling ,000 Metres This map is reproduced from Ordnance Survey material by Halcrow on behalf of the Environment Agency with the permission of the Controller of Her Majesty's Stationery Office. Crown Copyright. Unauthorised reproduction infringes Crown copyright and may lead to prosecution of civil proceedings. Licence Number GD03177G Great Yarmouth North Denes Strengthen & install erosion protection Strengthen & maintain erosion protection Setback Rollback Setback & remove piles Flood Defence Proposals for Acle to Great Yarmouth (Compartment Number 11 River Bure )