Ouse and Derwent Internal Drainage Board - Policy Statement

Flood Protection and Water Level Management



1.1    This policy statement has been prepared by Ouse and Derwent Internal Drainage Board to provide a public statement of the Board's approach to its management of flood risk and water levels in its area.


1.2    The Department of the Environment, Food and Rural Affairs has policy responsibility for flood and coastal defence in England. However, delivery is the responsibility of a number of flood and coastal defence "operating authorities" which includes the Ouse and Derwent Internal Drainage Board.

1.3    The Government has published a policy aim and three objectives for flood and coastal defence (1). To ensure a more certain delivery of the aim and objectives by the individual operating authorities the Government has published a series of high level targets (2). The first target requires each operating authority to publish a policy statement setting out their plans for delivering the Government's policy aim and objectives in their area. This will include an assessment of the risk of flooding in their area, and what plans they have to reduce that risk.

1.4    This policy statement fulfils that requirement.We are providing a copy to the Department of the Environment, Food and Rural Affairs, the Environment Agency and the local authorities within the Board’s area. Copies are available from the Board's offices at Derwent House, Crockey Hill, York, YO19 4SR.


2.1    The Ouse and Derwent Internal Drainage Board supports the Government aim and objectives for the management of flood risk and water levels. The Board’s policy will be consistent with them.

Policy Aim

To reduce the risk to people and the developed and natural environment from flooding and coastal erosion by encouraging the provision of technically, environmentally and economically sound and sustainable defence measures.
            Section 3 below sets out the Board’s plans for reducing or managing the flood risk in the Board’s District

Objective (a)

To encourage the provision of adequate and cost effective flood warning systems.

The Board will assist the Environment Agency wherever possible in its provision of adequate and cost effective flood warning systems. The Board will co-operate with the Agency in response to flood emergencies and participate, as necessary, in exercises to develop and test emergency response procedures.

Objective (b)

To encourage the provision of adequate economically, technically and environmentally sound and sustainable flood defences.

In meeting its obligations the Board will consider its activities within the wider natural and developed environment seeking to ensure the avoidance of any adverse impact. It will equally co-operate with other drainage authorities and organisations to ensure adverse impacts do not arise as a result of other activities.

The Board will carry out its maintenance and improvement works in an efficient and cost effective way. Where appropriate using best practice and accessing appropriately qualified advice when necessary.

To achieve this the Board will encourage the provision of adequate, economically, technically and environmentally sound and sustainable flood protection and water level management measures and seek to control that development which could increase the risk of flooding.

Within the Board’s District a significant part the area is at some risk of flooding and the Board will seek to maintain this risk at acceptable levels through appropriate improvements and the implementation of a sound maintenance strategy. They will also seek to ensure that the Environment Agency maintains, at a satisfactory standard any flood defences which also afford protection to the District.

Objective (c)

To discourage inappropriate development in areas at risk from flooding and coastal erosion.

The potential impact on flood risk through future development in the Drainage District, or in the wider catchment draining to the District, is fully recognised by the Board. It will take an active role in the assessment of structure planning, local plans and individual applications to ensure flood risk is not increased. Where appropriate the Board will secure from Developers contributions to cover the cost of both immediate and longer-term works necessary in ensuring that any potential increase in flood risk is removed


3.1    Key Details

As mentioned in Section 2, a significant part of the Board’s District is at some risk to flooding. That risk is substantially controlled although varying standards of protection apply. The following are the key details of the District:

            Catchment Area draining to and including the District                             19800ha
            Total area of the District                                                                           19800ha
            Area of Agricultural Land                                                                         17594ha
            Area of other land including property,
            Highways, etc.                                                                                          2206ha

3.2    Board Maintained Infrastructure

            Pumping Stations                                                            5 No.                                                                
            Watercourses                                                               264km

3.3    Regulation of Activities

The Board will exercise as required its powers under the Land Drainage Act 1991 and its Byelaws to ensure that its activities in and alongside its drainage system do not reduce flood protection standards and unnecessarily increase flood risk.

3.4    Standard of Protection

Through the operation and maintenance of pumping stations and the channel system the Board will seek to maintain a general standard capable of providing flood protection to agricultural land and developed areas of 1 in 10 and 1 in 50 years respectively. This likely return period can not be taken literally and should be considered as a chance of some overspilling from the system taking place each year as being 10% and 2% respectively.

3.5   Management of Flood Risks

The Board monitors the condition of its pumping station and watercourses; particularly those designated as critical, overspilling from which could affect property. Consistent with the established need a routine maintenance programme is in place to ensure that the condition of the assets is commensurate with the standards of protection which are sought.

Where standards are not at the policy level, improvement works, where they can be demonstrated to meet with DEFRA criteria, will be considered and undertaken as appropriate.

The Board welcomes from its agricultural ratepayers, special levy councils and members of the public any comments on the condition of its system, which could lead to any increased flood risk.

3.6   Publicity

The Board will seek to promote the need for works in its District and create a rational understanding among people who live and work in it as to what the flood risk is and the efforts made to control it. They will also seek to achieve directly and through local councils a culture within which the watercourses are seen as vital to controlling flood risk, whilst providing an interesting aquatic habit and dissuade abuse of them through dumping waste or obstructing flows in other ways.


4.1   The Ouse and Derwent IDB has nature conservation duties under the Land Drainage Act 1991, the Wildlife and Countryside Act 1981 and as a competent authority under the Conservation (Natural Habitats C) Regulation 1994. The Board will fulfil these in a positive way.

Much of the Boards watercourse maintenance work of vegetation control and de-silting is a vital and routine requirement. whilst inevitably some short term impact will arise, this management is essential also to maintain the diverse aquatic habitat in the district. The Board maintains only a small proportion of the total watercourse length in the district, the significant majority being the responsibility of the riparian landowners.

When carrying out works, be it maintenance or improvement, and consistent with the need to maintain satisfactory flood protection standards, we will aim to: -
a) avoid any unnecessary or long-term damage to all the natural habitats
b) take appropriate opportunities to enhance habitats.

4.2    The Board will play its role in sustaining any Water Level Management Plans prepared for SSSI sites within the District and, in conjunction with English Nature and other interested parties, review the plan in accordance with DEFRA guidance.


Ouse and Derwent IDB will review this Policy Statement within a period not extending beyond 5 years.


1    Strategy for Flood and Coastal Defence in England and Wales DEFRA and Welsh Office, September 1993
2    High Level Targets for Flood and Coastal Defence Operating Authorities and Elaboration of the Environment Agency's Flood Defence Supervisory Duty DEFRA, Nov 1999.

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