The Bedford Group of Drainage Boards John... · 2016-11-16 · Visit to Bedford Group of Drainage...
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Visit to Bedford Group of Drainage Boards Nadine Dorries MP 22 March 2010 1 The Bedford Group of Drainage Boards The Importance of Maintenance Delivery in Watercourse Management John Oldfield ADA Local Authority Seminar Thursday 17 March 2010 Great Northern Hotel, Peterborough Watercourse Maintenance It is not a new science Priestman Cub dragline, 1937 Hitachi 360 O Excavator, 2009
Transcript of The Bedford Group of Drainage Boards John... · 2016-11-16 · Visit to Bedford Group of Drainage...
Visit to Bedford Group of Drainage Boards Nadine Dorries MP
22 March 2010
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The Bedford Group of Drainage Boards
The Importance of Maintenance Delivery
in Watercourse Management
John Oldfield
ADA Local Authority SeminarThursday 17 March 2010Great Northern Hotel,Peterborough
Watercourse Maintenance It is not a new science
Priestman Cub dragline, 1937
Hitachi 360O Excavator, 2009
Visit to Bedford Group of Drainage Boards Nadine Dorries MP
22 March 2010
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Land Drainage Act 1991 Power : Duty
• 1 – Duty to general supervision over all matters relating to drainage in District• 12 - Duty to further conservation when exercising its powers.• 14 - Power to carry out maintenance, improvement and capital works.• 23 – Consent no person shall obstruct or affect flow• 64 - Power to enter onto land to carry out works. • 66 - Power to create new byelaws.
Note All rivers, watercourses and culverted watercourses are owned by the landowner
land drainage: flood risk management: surface water management
Philosophy of rarely could individuals protect themselves, so Statutory Authorities empowered for the common good of land drainage and flood risk management
Diagram of Flood DefenceOperating Authorities
??Who does what where??
Main River (Environment Agency)
Ordinary Watercourses (Local Authorities)
The sea
Ordinary Watercourses (Internal Drainage Boards)
WTW
STW
Water & Sewage Companies
1st tier Local Authorities (highways)
Visit to Bedford Group of Drainage Boards Nadine Dorries MP
22 March 2010
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Manage & Reduce Flood Risk
The need for maintenance
Visit to Bedford Group of Drainage Boards Nadine Dorries MP
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The need for maintenance
The need for maintenance
Visit to Bedford Group of Drainage Boards Nadine Dorries MP
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The need for maintenance
The need for maintenance
Visit to Bedford Group of Drainage Boards Nadine Dorries MP
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The need for maintenance
Heavily Modified WatercoursesEngineering Design
Q = V x AFlow = Velocity x Area
Manning’s roughness coefficient
Visit to Bedford Group of Drainage Boards Nadine Dorries MP
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Heavily Modified WatercoursesEngineering Design
Engineered Watercoursesno maintenance = reduced capacity
Visit to Bedford Group of Drainage Boards Nadine Dorries MP
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Access for maintenance& EA/IDB/LA Byelaws
“little and often maintenance”
9m
Must Avoid Poor Access
Visit to Bedford Group of Drainage Boards Nadine Dorries MP
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Must Avoid Poor Access
Must Avoid Poor Access
Visit to Bedford Group of Drainage Boards Nadine Dorries MP
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Risk Based Maintenance Regimeto only work where necessary
Category 1A (critical) Category 1 annualMaintenance
Category 2 2 – 6 years Maintenance
Category 3 More than 6 years
Maintenance
Asset Surveysas per
Defra review of IDBs
Visit to Bedford Group of Drainage Boards Nadine Dorries MP
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Red Amber GreenCondition Rating
Annual Works Programme on www.idbs.org.uk
Past programme Current programme
Visit to Bedford Group of Drainage Boards Nadine Dorries MP
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Development Pressures20,000 houses, jobs and infrastructure.... Bedford
35,000 (by 2016) / 68,000 (by 2031) houses..... Milton Keynes
Development Densities in MK1969 – 20 units per ha2000 – 27 units per ha
2008 - ? 50+ units per ha ?
Message to Planners and Developers Access for maintenance
Access required for machineryand dredged material
Visit to Bedford Group of Drainage Boards Nadine Dorries MP
22 March 2010
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Swales - Shallow grass channel Maintain with tractor flail
Message to Planners and Developers Access for maintenance
Ditch – deeper & wettermaintain with an excavator which requires access and can damage
metalled surfaces
Message to Planners and Developers Access for maintenance
Visit to Bedford Group of Drainage Boards Nadine Dorries MP
22 March 2010
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Dry / Wet Flood Storage Reservoircan provide amenity value and can be
maintained with an Aebi
Message to Planners and Developers Access for maintenance
Wet Flood Storage ReservoirMaintain with floating plant
Message to Planners and Developers Access for maintenance
Visit to Bedford Group of Drainage Boards Nadine Dorries MP
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2008
2000
Conservation best practicereed margins and hedgerows (on 1 bank)
Visit to Bedford Group of Drainage Boards Nadine Dorries MP
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Must balance the human environment and natural environment
Duty to protect protected species
No Duty to protect people!
Visit to Bedford Group of Drainage Boards Nadine Dorries MP
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In 1998 the Surface Waters Group decided to promote its policies through the production of the Marston ValeSurface Waters Plan. Published in 2002.
Identifies opportunities for serving developments identified in the Local and Structure Plans with strategic surface water drainage and flood risk mitigation facilities. (i.e. align development aspirations and flood risk management)
Strategic Leadership with Surface Water Management Plans
Growth and Flood Risk Problem Areas
Marston ValeSurface Waters Group
Drainage Authorities
Planning Authorities
Amenity Management
Hannah Reed
Consulting Engineers
(Local Delivery Vehicle)
Visit to Bedford Group of Drainage Boards Nadine Dorries MP
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Master PlanDetailed solution to Integrated Urban Drainage
Structure and Local Plan used to identify growth demand
Pressure to align flood risk management with growth
Surface Waters Management Plan catchment boundary
Residential
Employment
Visit to Bedford Group of Drainage Boards Nadine Dorries MP
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Message to Planners and Developers Strategic, Integrated and Maintainable Sustainable Drainage Systems (SUDS)
9m
Message to Planners and Developers Sustainable Drainage Systems (SuDS)
strategic maintainable public exceedance
30,000 cubic metres flood storage reservoir : 0.2 cubic metre water butt
Visit to Bedford Group of Drainage Boards Nadine Dorries MP
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Message to Planners and Developers Sustainable Drainage Systems (SuDS)
strategic maintainable public exceedance
Large, publicly maintained flood storage reservoir : flooded, small private reservoir
Strategic and Integrated infrastructure maintained by Public Authorities
Minimize Flood Risk with Planned and Maintained Infrastructure
