Ely Internal Drainage Boards

Ely Group of Internal Drainage Boards

The Drainage Office, Main St, PRICKWILLOW, Nr Ely, Cambridgeshire, CB7 4UN

Swaffham Conservation Statement

Internal Drainage Boards are established in low lying areas of England and Wales where flood protection and land drainage are necessary to sustain both agriculture and developed land use.

There are around 250 I.D.B.s covering an area of some 1.2 million hectares. A high proportion of this area requires pumped drainage to evacuate surplus land drainage water.

The functions of the I.D.B.s and the Environment Agency do not overlap and are specified clearly in The Land Drainage Act 1991 and The Water Resources Act 1995.

Internal Drainage Boards have a duty under S.14 of The Land Drainage Act 1991 to exercise supervision of all matters relating to drainage of land within their Districts.


The Swaffham Internal Drainage District is situated north east of the City of Cambridge, part of the “South Level Fens”.

The District boundary encloses an area of 5,234ha with a total pumped catchment of 6,273ha.

The eastern boundary of the District is formed by the River Cam. The District extends to the Wicken Ridge in the north and to the edge of the fen in the east, where the peat fen runs into the chalk slopes and high sandy heath land of Suffolk.

The District is dissected by the “lodes” – Wicken, Burwell, Reach, Swaffham and Bottisham which form seven distinct and separate catchments which are drained to the Board’s single pumping station site at Upware.

The District comprises mainly of high grade agricultural land much of which is below mean sea level and considerably below “flood level” and is therefore totally reliant on pumped drainage for its existence as it has been for many years.

The Board undertake their drainage/water level management responsibilities by designating and maintaining a network of 83.8km of drains which gravitate to the Board’s Upware Pumping Station. Water levels are terraced/controlled from the upper reaches, at a number of structures in the Board’s drains to the Upware Pumping Station where surplus land drainage water is discharged to the River Cam.

The Board have to deal with a considerable input of spring water which outcrops in the District from the chalk upland in addition to any surplus caused by precipitation.

Areas of significant habitation tend to lie on the areas of high ground on the District boundary from Wicken in the north Burwell and the Swaffhams in the east and the City of Cambridge in the south. However, the District contains a low concentration of private dwellings and agricultural properties and buildings that support many highly productive agricultural operations within the District.

The District also contains all infrastructure necessary to support domestic properties, business and agriculture such as gas, electricity and water supplies as well as means of access to other areas such as roads.
The quality of life of people living and working within the District is dependent upon the efficient effective operation of the Board.

This statement is an all embracing one and recognises the need for a positive move to identify and safeguard the existing nature conservation resource, assess proposed and future developments and enhance the environment in relation to both maintenance and capital works carried out by the Board. The Board are committed, wherever possible, to adopting such practices, where they are possible and economically viable and at all times comply with the legislative requirements of English Nature.


Section 12 of The Land Drainage Act 1991 obliges the Internal Drainage Board and ministers to :-

(a) further the conservation and enhancement of natural beauty, consistent with any enactments relating to their functions;

(b) further the conservation of wildlife and geological and physiograpical features of special interest, consistent with any enactments relating to their functions;

(c) have regard to the desirability of;

(i) protecting and conserving buildings, sites and objects of archaeological, architectural or historical interest; and

(ii) preserving public rights of access to areas of mountains, moor, heath, down, cliff or foreshore and other places of natural beauty; and

(d) take into account the effects of any proposals on the preservation of rights of access and on the beauty or amenity of an area, or on wildlife, features, buildings, sites or objects.

Section 100 of the Environment Act 1995 redefines the term drainage to include:-

Defences against water (including sea water), irrigation other than spray irrigation, warping and the carrying on, for any purpose, of any other practice which involves the management of the level of the water in a watercourse.

The Environmental Impact Assessment (Land Drainage Improvement Works) Regulations 1999 (SI No. 1783) obliges the Board to carry out an environmental assessment or undertake a consultation process with various statutory consultees, to include English Nature, English Heritage and the Countryside Agency and publish a notice in the local press that they do not intend to carry out an environmental assessment, before carrying out any improvement works.


(a) Special Areas of Conservation (SACs) designated or proposed for designation under the European Community’s Habitat Species Directive (92/43/ECC);

(b) Ramsar Sites (wetlands of international importance);

(c) Special Protection Areas (SPAs) designated or proposed for designation under the European Community’s Council Directive 79/409/EEC on the conservation of wild birds;

(d) Species protected under the Wildlife and Countryside Act 1981 (as amended);

(e) Sites of Special Scientific Interest

(f) County Wildlife Sites

(g) Environmentally Sensitive Areas

(h) National and Local Nature Reserves

(i) Listed Buildings, archaeological sites, (scheduled) ancient monuments

(j) National Parks

(k) Structure plans and local plans incorporating county designations of nature conservation sites

(l) Public Rights of Way

(m) Any other sites of environmental interest that may be adversely affected by the blanket application of Board’s Byelaws

(n) Other sites of particular note

(o) A.D.A. “Find a drain” scheme

Attached map shows target areas in or adjacent to the District (excludes rights of way and listed buildings).

(e) Site of Special Scientific Interest

* Shippea Hill S.S.S.I. – water level management plan prepared by the Board and
agreed with all consultees
Stallode Wash S.S.S.I.

(f) County Wildlife Sites

Ely Ouse/Ten Mile River
River Lark
Little Ouse River

(o) A.D.A. “Find a drain” scheme

White House Road Drain


The Board recognises the significance of drains and watercourses within the District as wildlife habitat. The Board will consult with English Nature and the Wildlife Trust with regard to carrying out maintenance and capital works. This does not preclude any other conservation body that may have a positive and helpful input to achieving positive enhancement in connection with the Board’s operation.

Consultations with regard to the above operations will be primarily directed through English Nature.

English Nature has been provided with information with respect to the Board’s maintenance operations and they will be further consulted should advice be required on areas of alternative working practices should they wish these to be adopted. This is in addition to informal liaison and discussion taking place on a regular basis.

Maintenance Work

Maintenance works are defined as the operations carried out by the Board to maintain the efficient, designated function of the existing drainage system. This includes desilting and “batter removal” to ensure bed width, drain capacity and gradient are maintained. This work is normally carried out with excavating plant with work taking place from September to March.

Maintenance of the main drain system is undertaken to a predetermined long term programme adjusted on an annual basis to take into account emergency and improvement works.

In addition to maintenance works the Board also carries out weed control. The Board employs the following methods at present on an annual basis.


Flailmowing is undertaken ahead of excavator work to trim batters to allow operators to see their work. Some flailmowing is undertaken on small drains to “tidy up” but cosmetic flailmowing which has little effect on the function/capacity of drains is avoided. However, most drains are flailmowed at least once every two years. Leaving batters uncut has a benefit to flora fauna and wildlife. Work normally takes place from August to February.

Excavator mounted weedcutting bucket/rake

The weedcutting bucket with cutting knives attached to the leading edge, cuts and removes weeds from the wetted channel area of the drain. Work normally takes place from August to February.

Weedcutting boat

The weedcutting boat starts work in May and cuts the larger main pumping drains, as necessary, through to September. It is necessary to cut these drains during the summer for these drains to convey pumping flows. Cut weeds are removed from these drains with the hydraulic lift/rake attached to the front of the boat to prevent deoxygenisation of watercourses through decaying weeds. Access for the weedcutting boat is assessable to approximately 19km. of main drain.

Herbicide Use

Only herbicides cleared for aquatic use are used to control weed in the Board’s drains. Herbicide is only applied when other forms of weed control have been considered and the application of herbicide is considered necessary. They will only be used under the Control of Pesticide Regulations 1986 and the Food and Environment Protection Act 1985. They will only be used after application to/agreement with, the Environment Agency, who monitor all applications to watercourses.

Over recent years Glysophate in the form of an approved aquatic herbicide has been used to control (not eradicate) common reeds (phragmites comminus) with applications made with a weed wiper or hand held sprayer. Other approved aquatic herbicides have been used in the District over recent years but on a diminishing scale.

Trees, bushes, hedgerows

The Board’s Byelaws preclude the planting of trees, bushes and hedgerows within 9.0m of the top edge of any designated main drain. The Board discourage the planting of new trees, bushes and hedgerows within the Byelaw limit to maintain existing access for maintenance works. The Board support the planting of trees, bushes and hedgerows in other areas of the District.

Where these features exist, adjacent to a designated main drain, the Board manage such features (where it is their responsibility) to maintain existing access. Where a riparian owner is responsible for maintaining such features the Board require maintenance is carried out by the owner, under the Board’s Byelaws to maintain access for maintenance works to the Board’s drains.

All staff will be educated/supplied with information/training to allow them to undertake their duties with suitable consideration of the environment.

This description of the Board’s maintenance works is not exhaustive.

Capital Works

Capital works are works carried out to improve the existing drainage system of the District. This would include the cutting of new drains, improvement of existing drains and new works such as the construction of a new pumping station.

Schemes that involved widening and deepening an existing drain, where excavation into the sub-soil, or hard bed, of any drain was proposed, would be included.

All improvement works are subject to the requirements of The Environmental Impact Assessment (Land Drainage Improvement Works) Regulations 1999 (SI No. 1783) and are only undertaken by the Board after the requirements of this Act have been fulfilled.

Capital works can be undertaken, as programmed, at any time of the year. Works will be assessed to include guidelines to be incorporated into work programmes to minimise any risk to and safeguard (and enhance if possible) any existing nature conservation resource affected by such works.

Operational Staff

All staff will be educated/supplied with information/training to allow them to undertake their duties with suitable consideration of the environment.

Back to top

Land drainage is the primary function of the Board. However, consideration of positive enhancement of the environment with respect to the Board’s works is now a pre-requisite with respect to operation and a major vehicle for achieving this enhancement is water level management. Wherever the principle of water level management can be applied without putting at risk life, property or livelihood it should be adopted with agreement of all interested parties.

The Board recognises the Government’s commitments to biodiversity action plan targets and acknowledges that water habitats within the District will form a key component of such plans. The Board have made positive moves towards maintaining and improving the biodiversity of the District in the management of the District in accordance with this statement and, for example, the preparation and implementation of water level management plans for sites of special scientific interest, as detailed under Target Conservation Headings and the designation of White House Road Drain as a Conservation Area under the A.D.A. “Find a drain” scheme.


The Board’s operations are undertaken with a view to sustainable management of the District. The Board need to consider the financial implications of all works undertaken and the effect on the ratepayers of the District.


Water vole surveys being undertaken in cooperation with the Wildlife Trust ahead of maintenance works.

Consultation with the Hawk and Owl Trust in respect of erection of owl boxes at some pumping station sites.