SALMON’S BROOKFLOOD ALLEVIATION SCHEMEPlanning Panel9th July 2012Highlands School, Grange Park, Enfield
Presentation team Graham Cowell (Environment Agency) Steve Whipp (Environment Agency) Mike Gara (Environment Agency) Roland Grzybek (Halcrow) Windsor Young (Volker Stevin Mike Ferens (MMA)
Flooding in Enfield• Enfield has a history of flooding• Most recently in October 2000• 192 properties flooded• Approximately 2000 properties at risk• 5% chance of flooding in any year Flooding, October 2000Flooding in Granville Road, October 2000
Flood Alleviation Scheme Objectives Reduce the risk of flooding to 1393 properties (2587 households), of which 727 properties will be protected from a 1.3% (1 in 75) AEP flood. Reduce the risk of flooding from Saddlers Mill stream coming up through the manholes in Montagu Road. Provide environmental and amenity enhancements to the area as part of the works. Benefit – cost ratio of 6.2 for a 1.3% standard of protection. Aim to start construction in 2012/13
Flood Alleviation Scheme Elements Saddlers Mill Flood Storage at Stream Boundary Ditch Enfield Golf Course Raised defences Sandhurst Road & Falcon along Salmons Walk FieldsEnfield Golf Course & New culvert routeCheyne Walk OpenSpace under Montagu Road Montagu Flood Storage at Road Recreation Ground Montagu Road Salmons Walk Recreation Ground & Salmons environmental Brook improvements Localised Measures Montagu Road to address Saddlers Mill stream
Flood Maps Pre & Post Scheme –Saddlers Mill stream area 1 in 75
Flood Maps Pre & Post Scheme –Montagu Road Area 1 in 75
Enfield Golf Course Enfield Golf Flood embankment Club Cheyne Walk Allotments Open Space Access tracks Store flood water temporarily Provide an environmentally sensitive design Mitigate any impacts on the Golf Course Provide a structure that is safe to operate with minimal maintenance Conform to the Statutory Reservoirs Act 1975 No increase in flood risk to those properties upstream of the structure
Enfield Golf Course What the proposed flood embankment will look like at Cheyne Walk Open Space What the proposed flood embankment will look like at Enfield Golf Course
Montagu Road Area Montagu Road Recreation Ground, environmental improvements amenity creation & new flood storage Montagu Road, new culvert route Salmons Walk, raised defences along walk
Salmons Walk Require raised defences along Salmons Walk - approx 1m x 550m both banks Provide the appropriate environmental enhancements Enhance the path to a combined footpath and cyclewayAn artist’s impression of Salmons Walk after the scheme – looking towards standard.Montagu Road
Montagu Road Recreation Ground Store flood waterNew paths Shaped river temporarily banks Provide Concrete removed environmental Pavilion enhancements to the New open watercourse and channel surrounding area in a restored river setting New fixedNew trees structures to Meet the current control water needs of users of the Football Pitch Raised ground and open space Conform Existing new shrubs to the Statutory flood New Reservoirs Act 1975 storage embankments
Montagu Road Recreation Ground An artist’s impressions of Montagu Road Recreation Ground after the scheme << Looking towards Zambezi Drive from near the pavilionLooking southfrom near thepavilion >>
Construction Access – Enfield GolfCourse – proposed routeConstraints Open space access via Uplands way Cheyne walk would require car parking restrictions along its whole length Pinch points – vehicles unable to exit safely at Landra Gardens due to traffic restrictions (bollards etc) School hours
Construction Access – Salmons Walk– proposed routeConstraints Linear site – access required at both ends. Only entrances to Salmons Walk. Limited access from Plevena Road Main access Montagu road
Construction Access – Bury StreetWest – proposed route
Access during construction – EnfieldGolf Course & Cheyne Walk OpenSpace Golf course will remain open with all holes playable - slightly shortened 9th hole (although localised improvements within the golf course currently being considered with EGC may cause more temporary disruption). Cheyne Walk • Pedestrian access at all times to allotments and open space. • Vehicular access available at evenings and weekends. Vehicular by arrangement with contractor in special circumstances during working hours. Deliveries ok by arrangement Barnabas Court – pedestrian access and vehicular access all times.
Access during construction –Salmons Walk Due to our legal health and safety obligations for a working construction site to protect members of the public we cannot allow access during the works. We will sign an alternative route. e.g. Cemetery Walk and local roads. Post scheme – Salmons Walk will be provided with a new combined cycleway and footpath.
Access during construction –Montagu Road Access to current play areas, community centre and sports field will be maintained during the works. The minimum space possible will be occupied on the recreation ground to allow access to the open space during construction. Temporary traffic lights will be required while the culvert is constructed on the edge of Montagu Road To deliver materials to Salmons Walk there will be some construction traffic across Montagu Road.
Access during construction – BuryStreet West Site currently closed to general public – no change in access No impact on Enfield Council depot for day to day operations Works are very small-scale localised in-channel works. Construction duration estimated at a few weeks.
Planned Extent and duration of theworks Enfield Golf Course and Cheyne Walk Site set up and utilities diversions – 5 months Flume structure – 5 months Delivery clay – 3.5 months Embankment construction – 3.5 months Landscaping & finishing – 3.5 months Grass seeing – 1 month
Planned Extent and duration of theworks Salmons Walk Site set up and surveys – 1 month Flood defence wall right bank d/s – 11 months Flood defence wall left bank d/s – 11 months Sheet piling – 3 months
Construction noise and disturbanceGeneral Works will use construction best practice for which we have won numerous construction awards. We will operate under the Considerate Contractors Scheme – audited by an independent body. We will operate in standard working hours. We have planned our deliveries outside the rush hour and school run. We will operate within the requirements for noise levels. Plant and design has been chosen to minimise disturbance as much as possible. We will use modern anti-noise anti vibration construction machinery with appropriate silencing mechanisms. Condition surveys will be undertaken where required. We do not envisage that the works and associated site traffic will cause any structural damage to the properties along the proposed route.
These activities from previous projectshave not caused damage to properties
Stakeholder consultation to date: Stakeholder consultation to date includes: Public exhibitions, 2004, 2008, 2012. Public newsletters 2004, 2005, 2008, 2011 (council & MP), 2012 Area Forums 2010, 2012 Presentation Meetings Cemeteries Enfield Golf Club Enfield Council
Communication during construction Dedicated community liaison officer Local residents forum Local schools engagement 24 hour hot line Regular progress update
Flood Alleviation Scheme Benefits Best opportunity to reduce flood risk in the Lower Lee valley. Included by defra in their funding announcement for flood alleviation schemes for the last 2 years. Reduce the risk of flooding to 1393 properties (2587 households), of which 727 properties will be protected from a 1.3% (1 in 75) AEP flood. Reduce the risk of flood water from Saddlers Mill Stream coming up through the manholes in Montagu Road and in to properties. Provide bio-diversity, habitat creation and amenity enhancements to the area as part of the works. Prevent £156.2 million of damage in the 1.3% chance flood event.
Questions? Steve Whipp, Environment Agency, Senior User – Client Mike Gara, Environment Agency, Project Manager email@example.com.