Environment Agency. Title. POI / Status: For File Storage / Archive Doc Title: Exeter Phase 1 NTS

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1 Doc Ref: Exeter_FDS_Non_Technical_Summary_Phase_1_Final_Volume_1[1] Exeter Flood Defence Scheme, Phase 1 Volume 1: Non-technical Summary Reference number/code Environment Agency [Sector Code] Title

2 We are The Environment Agency. It's our job to look after your environment and make it a better place - for you, and for future generations. Your environment is the air you breathe, the water you drink and the ground you walk on. Working with business, Government and society as a whole, we are making your environment cleaner and healthier. The Environment Agency. Out there, making your environment a better place. Published by: Environment Agency Rio House Waterside Drive, Aztec West Almondsbury, Bristol BS32 4UD Tel: enquiries@environment-agency.gov.uk Environment Agency All rights reserved. This document may be reproduced with prior permission of the Environment Agency. Environment Agency Exeter Flood Defence Scheme Phase 1

3 Non-technical Summary Introduction The Scheme the We, the Environment Agency, are proposing a flood defence scheme (called Scheme ) in Exeter (Figure 1), in partnership with Devon County Council and Exeter City Council, to improve flood protection over the next 100 years. The Scheme includes improvements to existing flood defences, and the construction of new defences which will increase the standard of flood protection to a 1% chance of flooding in any given year. The study area for the Scheme encompasses areas that are susceptible to flooding between Cowley Bridge in the north and Countess Wear Bridge in the south. In recognition of the potential for economic growth in Exeter and the wider region that will benefit from improved flood defences, funding is available from central government.the Scheme development has been phased. Phase 1, which is due to start in Spring 2014, comprises works that reduce flood risk and do not require planning permission. Phase 2 comprises works that are generally more complicated, involving improvements and extensions to the existing network of flood defences; these will require planning permission. The Phase 1Works will be constructed at the following sites (see Figure 2): St Davids Railway Bridge on the Exe (hereafter referred to as Exe Railway Bridge ) (Site 1a) Trews Weir Fish Pass and Trews Side Spill Weir (Site 1b) Trews Flood Relief Channel (Site 1c) Ducks Marsh (Site 1d) Planning and Environmental Impact Assessment Figure 1: Location of Scheme An Environmental Impact Assessment (EIA) has been undertaken for Phase 1of the Scheme in accordance with the requirements of the EIA (Land Drainage Improvement Works) Regulations EIA is a process to assess the likely significant environmental effects of a proposed project together with ways to avoid or reduce any negative environmental effects. The findings of the EIA are presented in the Environmental Statement. The Environmental Statement, together with this Non- technical Summary, are also being advertised in local newspapers and made publicly available through our website prior to carrying out the works. We will carry out the Phase 1works using our Permitted Development Rights (Town and Country Planning (General Permitted Development) Order 1995), and in accordance with a Certificate of Lawfulness granted by Exeter City Council on 17 September

4 Under the Marine and Coastal Access Act 2009, a marine licence will be sought from the Marine Management Organisation for the Phase 1Works that are tidally influenced i.e. works downstream of Trews Weir. An EIA of the Phase 2 Works will be carried out separately to support a planning application in late impacts of both phases of the Scheme. Need for the Scheme Both Environmental Statements consider the combined The Scheme is intended to reduce the flood risk to people and property in Exeter, while enabling adaptation to climate change. The existing flood defences were built following the disastrous floods of 1960, though there is an extensive history of flooding from the River Exe extending back to Heavy rainfall in November 2012 resulted in flooding from the River Exe which again demonstrated the disruptive effects of flooding in the city. In addition, certain sections of the existing defences are coming to the end of their design life. An estimated 3,270 properties in Exeter could be affected by a River Exe flood event with a 1% chance of happening in any given year. Parts of the city are also at risk during more frequent (smaller) flood events. In some areas, the depth of flooding could reach 2m, with high rates of flow, presenting a risk to life. The threat of climate change will increase the risk of flooding in Exeter if flood defences are not improved, resulting in more frequent inundation of the city. Scheme Objectives In addition to reducing flood risk, the Scheme has the following specific objectives: - Providing a Scheme which helps create a better place and maximises environmental gains for people and wildlife, respecting landscape, views, recreation, navigation and cultural heritage; Involving local people and organisations to assist in the process of developing the optimal value for money solution; Avoiding, minimising or reducing negative environmental effects as a result of the Scheme; Minimising negative effects on the local economy, tourism, recreation and other activities during construction; Minimising health and safety risks throughout the life of the scheme; and Supporting and contributing to the objectives of the Water Framework Directive (explained further later in this document). Alternative Options Considered We considered a range of options for reducing flood risk in Exeter. The options of doing nothing or simply maintaining the existing flood defences were discounted as both would lead to an unacceptable increase in flood risk over time. We then considered a number of different engineering solutions comprising improvements to the existing defences, the construction of new defences and an upstream flood storage option in a rural area north of the city. These options were subject to discussions with stakeholders and the public. They were also subject to appraisal of cost, engineering considerations, and social/environmental risk and opportunities. The upstream storage option was rejected in the short-term due to cost 2

5 and potential land use impacts and therefore it was decided to develop a Scheme in the city. We identified a range of alternative sub-options to deliver the Scheme in Exeter, in discussion with key stakeholders and the public and following an inspection of the river channel, its banks and the associated floodplain to understand where existing flood defences need to be improved. We considered what could be carried out to provide safe flood storage and prevent the river from bursting its banks, where it would negatively affect people and the environment. The sub-options investigated included the removal of bridges constraining the flow of the river, the removal of weirs, additional/raised defences, dredging, bypass channels and property level protection. None of these options work in isolation, but when combined can provide increased flood protection to the city. After further appraisal and refinement, we selected the most appropriate option based on effectiveness, social/environmental considerations, and economic considerations. We then considered various design sub-options for Phase 1to reduce potentially negative environmental impacts and to integrate environmental improvements. Consultation We presented the flood risk management options and the preferred Scheme to the public and key stakeholders at various events including: Three Stakeholder Workshops in 2010 and 2011, to obtain views on the options, to present the results of option assessment work, to present the preferred Scheme and to explain changes in flood risk management funding. Meetings with Network Rail, South West Water, our partners Technical Officers, Community Groups, Exeter City Council Planning/Consenting Teams, Recreation/Business Interest Groups, Fisheries Interests, and businesses. A Public Exhibition in 2010 and two more in 2013, to introduce the option appraisal process and to consult with the public on the proposed Scheme. Key issues raised during the consultation events are summarised below: Potential impact on historic buildings including the Listed Fish Market; Need to protect wildlife; Need to consider impacts on Exeter s cycle routes and walking corridor; The standard of flood protection provided by the defences; The anticipated effects of weather and climate change on flood risk; Concerns regarding home insurance, flood flows over land and vulnerability of the elderly; Technical issues relating to flood maps and predicted flows through Exeter; Changes in views (e.g. around the Quay); Property privacy; Need for dredging/clearance of channel; Changes in water levels and impacts on water-based recreation; Meeting Network Rail requirements and protection of their assets; Need to ensure that the scheme does not impact on sewers. Comments and concerns raised by the public and consultees from all consultations have been fed into the design, helping to improve and develop the Scheme. 3

6 Newsletters and press releases will be issued to the public in Winter 2013/14 to explain the nature and timing of the works, and likely disruption. Regular updates relating to the construction works will also be provided on our website ( agency.gov.uk\exeter), via the Exeter Citizen, Express and Echo newspaper and through Twitter. We will develop a Community Action Plan in Spring 2014 to manage public concerns and expectations during the progression of Phase 2 of the Scheme. The Scheme The Phase 1Works will take place at four main locations and in summary will include removal of vegetation in the river, changing the slope and depth of the riverbed and riverbanks, improving access to the river for future maintenance, works to various weirs, creation of fish passes and creation and enlargement of channels to take more flood water (see Figure 2). In more detail the Phase 1Works will comprise: Exe Railway Bridge, St Davids Removal of an approximately 200m long and 12m wide area of vegetation by reducing ground levels by up to 1m beneath the bridge. River bank slopes here will be changed to improve the ability of the river to take flood water and support a greater variety of vegetation Wildlife improvements include the creation of wet hollows with gently sloping sides (known as scrapes ) that are attractive to wildlife, and installation of bat boxes. Provision for safe permanent access across Network Rail land for future maintenance. Reserving river gravels for re-use in other parts of the Scheme. Trews Weir - A proportion of flood water is currently directed into Trews Flood Relief Channel via a side weir to reduce the level of flood water in the river. The works here will include: Addition of a new fish and eel pass to the main Trews Weir. Reduction in height of the adjacent side weir, to divert more flood water out of the Exe, and addition of a fish pass. Temporary (to enable construction) reduction in bed levels of the river at varying depths of up to 3m upstream of Trews Side-Spill Weir over a 0.3 hectare area. Trews Flood Relief Channel and Stilling Basin Changing the slope of Trews Flood Relief Channel over approximately 1km and deepening it by up to 2.6m. Removing the existing Check Weir at the downstream end of the Flood Relief Channel to improve the ability of the river to cope with a flood and to enable habitat creation for wildlife. Provision of a new timber clad vehicle causeway at the upstream end of the Flood Relief Channel, and an access track along the eastern side of the channel for vehicles. access across the channel will also be provided. A new pedestrian Incorporation of a new and lower level meandering channel through the centre of the Flood Relief Channel, to replace the existing ditches. Within this there will be maintenance access areas, and connected pools and bays to maximise opportunities for wildlife (including fish). 4

7 Creation of a series of planted scrapes and shallow ponds, either side of the new channel, which will be seeded with locally characteristic plants. Soils and gravels excavated during work at Trews Flood Relief Channel will be temporarily stored for use during Phase 2, in order to reduce the demand for imported soil and avoid a large increase in construction traffic. The soil will be stored on our land at the northern end of Bromham s Farm Playing Field, on the south-west side of the channel, over a 3.5 hectare area. Ducks Marsh Area Removal of approximately 2ha of vegetation under Ducks Marsh Bridge and in the adjacent woodland. Construction of underground erosion protection to the bridge and reduction of ground levels at the bridge. Incorporation of a meandering channel (approximately 0.5km long) to reinstate flows through the existing woodland area. This will enable retention of much of the mature vegetation and create new wetland habitat. Creation of public viewpoints and interpretation boards in the proposed woodland. Provision of access for maintenance if required during and after a flood. Lowering of downstream end of Ducks Marsh to create a connected pool, to provide a variety of wildlife habitats. Reserving river gravels for re-use in other parts of the Scheme. To enable construction works at some of the sites, water levels in the river will be temporarily lowered over a distance of 1.6km by up to 1.5m (and 1m at Exeter Quay). This will take approximately three months. The Phase 2 Works, due to be constructed between Summer 2015 and Summer 2017, comprise all the remaining flood defence improvements along the river from Cowley Bridge to Countess Wear, including: Provision of new and raised flood embankments and walls Adjustments to Exwick Radial Gates Individual property protection Installation of flood gates New flood defences (likely to be self-raising) at the Quay New and improved habitat for wildlife and fisheries together with improvements to recreation and amenity facilities. 5

8 Doc Ref: Exeter_FDS_Non_Technical_Summary_Phase_1_Final_Volume_1[1] Figure 2: Phase 1 Works 6 Printed On: 08-Jun :47 WET Nr. Comments : ---

9 Construction, Operation and Maintenance Managing our impact on the environment We are committed to protecting the environment and people during the construction of the Scheme. Some disruption is unavoidable, but we will do all we can to minimise and manage this through the application of mitigation measures. All of the mitigation measures identified in the Environmental Statement will be incorporated into the construction contract documents by means of an Environmental Action Plan. The Environmental Action Plan will be used to ensure that the environmental mitigation and improvement measures are fully implemented as the works are built and operated. A dedicated Environmental Clerk of Works will be appointed to monitor compliance with the Environmental Action Plan. Upon completion of Phase 1Works, the affected areas of land (with the exception of the soil storage area adjacent to Trews Flood Relief Channel) will be reinstated. The reinstatement of all remaining land, together with the replanting of native tree species and vegetation, will be carried out upon completion of the Phase 2 Works. We will produce a manual indicating the monitoring, routine maintenance and other maintenance activities that will be undertaken. Managing traffic during construction We will carefully select the routes to be used by construction vehicles, in liaison with Exeter City Council and Devon County Council s Highways Department. We will also take other highway management measures (e.g. planning deliveries in advance, keeping the roads clean and temporary signage) to minimise disruption to local users and maintain maximum possible access during construction. These measures will be defined in a Traffic Management Plan. Our Phase 1construction programme We have programmed construction to minimise disruption to residents, tourists and businesses in Exeter, particularly those using the Riverside Valley Park, and to avoid impacting on protected species and fish. Tree felling and shrub clearance will be undertaken in Winter 2013/14 to avoid the bird breeding season. Further clearance of long grass is programmed for Spring 2014 to discourage reptiles from using these areas. The earthworks will be undertaken outside of the wetter winter period. The lowering of water levels at Exeter Quay will be undertaken between Autumn 2014 and Spring 2015 to avoid visual and navigation impacts on recreational users at the Quay during the summer months. Working hours are likely to be 8.00am to 6.00pm Mondays to Fridays with no weekend working. Quiet operations will be permitted between the hours of 7:00am and 7:00pm Monday to Friday. Deliveries and certain other activities will be further restricted to avoid peak commuting times as described in the Environmental Statement. Environmental impacts and the action we will take Local Community The overall Scheme (Phase 1and Phase 2 Works) will benefit the local community by reducing the flood risk to approximately 3,270 (rising to 5,730 in 100 years time) residential and commercial properties, infrastructure and recreational assets. We will 7

10 also create amenity features e.g. interpretation boards and viewpoints overlooking Ducks Marsh. The works will result in the loss of existing access across Trews Flood Relief Channel; however, a pedestrian access will be provided at the site of the existing vehicle access point to the allotment gardens and recreational areas. A new crossing for vehicles will be provided at the northern end of Trews Flood Relief Channel. As with most construction works, there will be some unavoidable but temporary disruption (notably noise and access disruption) during vegetation clearance and construction works. Some temporary closures of footpaths and cycleways will be required but will be minimised as far as possible. Measures to minimise any nuisance to nearby residents, recreational users and businesses have been identified and we will keep the local community fully informed of the nature and timing of the works. Lowering the water level at Exeter Quay is programmed to avoid the main tourist season. Biodiversity (Wildlife) The Scheme has been designed to significantly improve the river corridor for wildlife. The combined Phase 1and Phase 2 Works are designed to create, restore and reconnect wildlife areas, and to help meet national and county level biodiversity commitments. Approximately 2.4 hectares of woodland and scrub will be removed from river banks and the channel, some of which lies within the locally important Countess Wear and Exwick Weir County Wildlife Sites. These losses will be offset by a gain of 5.2 hectares of grazing marsh and wetland habitat, thus an overall net gain of 2.8 hectares of wetland habitat, in Trews Flood Relief Channel and at Ducks Marsh. The creation of over 6 hectares of woodland is proposed for Phase 2. Surveys have identified that birds, bats, reptiles, amphibians, badgers and otters could be present in the Phase 1sites. All of these species are legally protected and we have therefore taken precautionary measures to minimise risks to them. We will use good practice procedures for work near water to ensure that no contaminants or silt are released that could affect wildlife or their habitats. developed by qualified ecologists. These measures have been The River Exe supports important fish populations including migratory salmon and eels. The proposed works will not obstruct fish passage and care will be taken to ensure no pollution of to the river and ditches. New fish passes at Trews Weir and Trews Side Spill Weir will improve fish migration, and removal of the downstream check weir will reduce the risk of fish becoming trapped in the Flood Relief Channel after high flows recede. Invasive terrestrial and aquatic weed species have been identified within the Phase 1 sites. We have prepared a plan to control the spread of these species within the working areas and manage them where they extend beyond the site boundaries. Landscape and Visual Issues Changes to the local landscape and townscape will be inevitable during construction due to: the loss of vegetation and trees at Exe Railway Bridge, Trews Flood Relief Channel and Ducks Marsh; the construction of fish passes; and the presence of large equipment and general construction machinery. This will result in changes in views for those living or working close by, affecting some residential properties in Brunel Close, Weirfield Road, Weirfield Place, Cotfield Street, Gabriel s Wharf and Exe View 8

11 Cottages, a student block off Bonhay Road, two public houses, users of canal side allotments and pedestrians/cyclists. We have programmed construction in amenity areas around Trews Weir, to avoid the main tourist season as far as possible. We will retain as much vegetation as possible and protect existing vegetation from damage. The construction of an access across Trews Flood Relief Channel will change the engineered characteristics of the channel. Upon completion of Phase 1, other permanent changes in landscape will include the clearance of woodland adjacent to Exe Railway Bridge and at Ducks Marsh, the new fish passes at Trews Weir, the lowering of ground levels at Trews Flood Relief Channel, and the removal of the check weir. However, the Phase 1Works will also provide landscape improvements through the creation of wetland habitat as replacement landscape features. The management of existing woodland at Exe Railway Bridge will soften the appearance of the channel. The changes to the slope of the river bank and channel at Exe Railway Bridge, Trews Flood Relief Channel and Ducks Marsh will create a natural appearance and support a variety of wetland vegetation. These landscape changes will have limited impacts on views for the local community upon completion of Phase 1. Some slight improvements in views may be experienced by residents of the student block off Bonhay Road and rail passengers. People using the Riverside Valley Park and local cycle route across Ducks Marsh Bridge may notice a slight visual deterioration as visibility along the river will be increased and pylons become visible. Water There is potential for accidental spillages of fuels, oils and other materials during construction, which could pollute the River Exe and groundwater. Additionally, earth moving activities could release soil and sediment into the river, affecting water quality and wildlife. Our contractors will follow strict guidance on pollution prevention to avoid causing contamination during construction, especially when working near water. Landscaping and re-planting to stabilise soils will be undertaken as soon as practicable following earthworks. The soil stockpile at Trews Flood Relief Channel will be above the 1% flood level. We have assessed the Scheme for its compliance with the Water Framework Directive, which sets environmental quality objectives for all surface waters (e.g. River Exe, Exeter Ship Canal) and groundwaters. This has concluded that the Scheme is compliant and makes a positive contribution to the quality of the Exe by creating and improving wetland habitats for wildlife and fish. The Historic Environment There are two listed buildings within 100m of the Phase 1sites, Trews Weir Cotton Mill and Old Match Factory both located near Trews Weir. As there will be no construction traffic past these, no significant impacts are anticipated. Construction activities will directly affect the locally important and post-medieval Trews Weir through the construction of a fish pass. We will carry out detailed archaeological recording at these weirs and archaeological supervision of the works will take place to record any significant deposits exposed. Soils will be stored on Bromham s Farmstead archaeological site but disturbance will not extend below the previously disturbed ground and therefore no impact will occur. No other known archaeological sites are anticipated to be impacted by the works. 9

12 There is a low risk of encountering archaeologically interesting soils associated with former channels of the river during the works at Exe Railway Bridge, Ducks Marsh and Trews Weir. We will ensure that there are clear reporting mechanisms if any sites of interest are identified during the works. The completed Scheme will provide an improved standard of flood protection to a variety of sites of historic interest, including Listed Buildings, Conservation Areas, Scheduled Monuments and over 50 non-designated heritage assets. Traffic and Transport Construction will require deliveries of materials and construction plant, which will increase traffic flows on Station Road, the A377 and A379 Bridge Road. We have selected the main access routes to avoid busy shopping areas and minimise the use of narrow residential streets, and deliveries will be restricted to avoid weekends and peak commuting hours. We will prepare a plan outlining how we will minimise truck traffic, restrict deliveries to quieter times of day, keep highways clear of mud and debris, and minimise access restrictions. With these measures in place, the impacts on road and river users during construction will be slight, but cannot be eliminated completely. The completed Scheme will have significant benefits for roads, the railway and public access by reducing the risk of disruption due to flooding. Soil, Geology and Hydrogeology There are no protected geological sites or soils with high sensitivity within the Phase 1 sites. There are however, likely to be localised impacts on ground conditions and soil structure as a result of changes in land and soil-stripping for construction of site compounds, storage areas and working areas. Soils stored at Bromham s Farm Playing Field will only be stored to an approximate height of 1.5m to avoid soil compaction. There are no historical landfills in the area of proposed works and there is limited potential for encountering historic contamination as the land was used for agriculture prior to the construction of the existing flood defence scheme. The Scheme will provide an improved standard of protection against flooding for existing land uses including landfills within the floodplain, thereby helping to prevent pollution. Natural Resources and Sustainability We have incorporated environmentally sustainable techniques and materials into the design of the Scheme. In particular, excavated soils from ground lowering and works to channels will be re-used for landscaping, to improve wildlife habitats and the visual appearance of the Scheme. Any gravels removed from the river during dredging will be re-used elsewhere in the river for habitat creation. Some of the felled timber will be made available to the local community, used for biodiversity improvements outside of the floodplain or re-used during Phase 2 of the Scheme. We will ensure that our contractor uses well-maintained equipment and implements construction procedures that minimise vehicle emissions and ensures the sustainable use and disposal of materials. 10

13 Cumulative impacts An assessment has been undertaken of the potential for cumulative impacts (e.g. combined impacts) related to the various components of Phase 1, the components of both Phases 1and 2, and other plans and projects. The in-combination impacts as a result of Phase 1are outlined in earlier sections of this Non-technical Summary. No additional cumulative impacts have been identified because the negative impacts during Phase 1will be localised, affecting only those in close proximity to the working areas. Due to the separate timing of the Phase 1and 2 Works, and some geographical separation, there is little potential for cumulative construction impacts (e.g. combined impacts of dust, noise, visual disturbance). The temporary storage of stockpiled soils, which will be retained for use during Phase 2, will minimise waste and reduce vehicle movements related to importing and exporting materials from the site. There will be significant beneficial cumulative impacts associated with both phases of the Scheme through combined improvements to recreational facilities and access, an overall net gain of habitat, improved fish passage and combined benefits to the local economy from the prevention of flooding. A proposed hydro-electricity scheme by Exeter City Council could be co-located with Trews Weir fish pass and we are currently working with the council to ensure that the scheme does not negatively affect any possible hydro-electricity plans. Conclusions Building the Scheme will cause temporary disruption to the local community, as well as to wildlife and other environmental features. The disruption will last from Winter 2013 until Spring Some riparian vegetation loss resulting from Phase 1works will be permanent, although larger areas of riparian habitat will be created elsewhere. Through consultation and by undertaking an EIA, we have sought to avoid or minimise these impacts to an acceptable level. The flood defence scheme is expected to bring significant long term benefits to Exeter by reducing (but not eliminating) the risk of flooding to large areas of the city containing housing, businesses, transport links, public spaces as well as areas of high historic and amenity heritage value. The Scheme will not only improve protection to people, property and the environment from flooding but also deliver significant habitat creation, improved landscapes and improved amenity. The amenity improvements in Phase 2 will bring further benefits for tourism and also provide improved access and recreational features for local residents, businesses, tourists, commuters and recreational users. Comments Copies of the Environmental Statement together with copies of the plans and supporting information will be made available for inspection on our website (to be confirmed) and at the following address during normal office hours: Environment Agency Manley House Kestrel Way Exeter EX2 7LQ 11

14 Copies of this Non-technical Summary are available at the same address. Comments can be made by writing to Julian James at the same address within 28 days of publication of the Environmental Statement. We will publish an advert in two local papers and also on our website consultation page ( The Environmental Statement will be a supporting document to this advert, and comments relating to the likely environmental impacts of these works should be made to the address stated on the advertisement, within 28 days of the publication date. 12

15 Would you like to find out more about us, or about your environment? Then call us on (Mon-Fri 8-6) or visit our website incident hotline (24hrs) floodline Environment first: This publication is printed on paper made from 100 per cent previously used waste. By-products from making the pulp and paper are used for composting and fertiliser, for making cement and for generating e nergy.