water abstraction getting the balance right The Colne Catchment Abstraction Management Strategy December 2007 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: 08708 506506 Email: [email protected] www.environment-agency.gov.uk © Environment Agency All rights reserved. This document may be reproduced with prior permission of the Environment Agency. Colne Rivers CAMS area overview River Ver HARPENDEN River Gade HEMEL HEMPSTEAD ST ALBANS HATFIELD BERKHAMSTED River Bulbourne River Colne CHESHAM River Chess AMERSHAM WATFORD River Misbourne RICKMANSWORTH BEACONSFIELD River Colne CHALFONT COMMON SLOUGH Legend Towns The Colne CAMS area N CAMS Rivers Other rivers Grand Union Canal (c) Crown Copyright. All rights reserved. Environment Agency 100026380, (2006) 0105 20 Kilometres Environment Agency Catchment Abstraction Management Strategy 1 Contents Section 1 Your Local CAMS 4 Section 2 The Colne CAMS area 6 2.1 Introduction to CAMS area 6 2.2 Hydrology and geology 6 2.3 Conservation 7 2.4 Ecology and fisheries 7 2.5 Industry and agriculture 7 2.6 Water quality 7 2.7 Water abstraction 7 2.8 Recreation and tourism 8 Section 3 Main principles of abstraction licensing in the Colne catchment 9 3.1 National principles 9 3.2 Catchment water resource availability 13 Section 4 Abstraction licensing strategy 15 4.1 Significant Local Issues for Licensing – Thames Q50 Constraint 15 4.2 Water Resource Management Unit 1 – Upper and Mid-Colne 16 4.3 Water Resource Management Unit 2 – Lower Colne 18 Section 5 Strategy actions 20 Glossary 22 List of Abbreviations 29 Appendix 1 Outline structure and information in technical document 30 2 Environment Agency Catchment Abstraction Management Strategy – Consultation Document Document structure and accompanying documents What are CAMS? Sections 1 and 2 outline what this strategy is for and the area that it covers. The abstraction licensing strategy This is the main part of the document. If you are an existing water abstraction licence holder it is this section that outlines what this strategy will mean for you. If you want to abstract water it outlines where water is available for further abstraction. Section 3 of this document outlines the main principles of abstraction licensing that we follow in the catchment. Section 4 outlines in more detail our abstraction licensing strategy for each part of the catchment. Section 5 outlines how we are going to implement the strategy. Technical information The detailed technical information used to develop this strategy and information about how we made our decisions is included in Appendix 1. If you would like a copy of the CD, please contact the Water Resources Officer (details on page 5). Updates to this strategy We will update this strategy every year. The update will be published on our website at www.environment-agency.gov.uk/cams. Please contact us on 08708 506506 if you want more information. Environment Agency Catchment Abstraction Management Strategy – Consultation Document 3 1.0 This strategy sets out how we will manage water resources in the catchment and provides you with information about how we will manage existing abstraction licences and the availability of water for further abstraction. Your local CAMS This is the Catchment Abstraction Management Strategy Gade, Bulbourne, Chess and Misbourne, and their (CAMS) for the Colne catchment. It sets out how we will tributaries. The Colne flows into the River Thames manage water abstraction until 2014. It outlines where upstream of Teddington Lock. Throughout the water is available, and also, if relevant, where we need catchment the Grand Union Canal interlinks with the to reduce current rates of abstraction. We also outline Colne, Gade and Bulbourne rivers. our policy on time-limited licences and whether existing The north and west sections of the catchment lie within licences should be renewed and, if so, on what terms. the Chilterns. This is characterised by chalk streams, If water is available we will give you an indication of the rural landscapes and traditional towns. The Chilterns reliability of a potential abstraction licence. are designated as an Area of Outstanding Natural Once you have read this strategy, if you want to abstract Beauty (AONB) in recognition of their exceptional water, you should contact us to find out if you need an landscape qualities. Approximately half of the Chiltern abstraction licence. If you do require a licence we will AONB is located within the Colne CAMS Area. The advise on the likely reliability of a proposed abstraction central, south and eastern parts of the catchment are and any issues that could affect the likelihood of a more densely populated and urban. These areas have licence being issued. been influenced by gravel extraction and urban fragmentation. However pockets of the lower Colne You can get more information about water availability Valley retain a rural character and the rivers, reservoirs and how to apply for an abstraction licence by and gravel pits provide a green corridor. contacting us on 08708 506506. There are nine water-dependent Sites of Special We are now using CAMS to manage water resources at a Scientific Interest (SSSIs) in the Colne catchment, in local level. They allow us to consult with the local addition to the Habitats Directive site of South West community and other interested parties in our work to London Waterbodies Special Protection Area (SPA). balance the needs of abstractors and other water users with those of the water environment. Our consultation A technical document for the Colne CAMS, which process will result in a local licensing strategy and a contains the detailed technical information on which decision on whether time-limited licences should be we have based this strategy, is available on CD. You can renewed and on what terms. All catchments in England also view a printed copy of this document at the and Wales will have a CAMS. The Colne CAMS covers an address overleaf. area of approximately 1014 km2 to the north-west of The document Managing Water Abstraction: The Greater London. The catchment covers parts of Catchment Abstraction Management Strategy Process Bedfordshire and Hertfordshire in the north, and sets out both the national policy and the regulatory Buckinghamshire and Middlesex in the south. The framework within which CAMS operates. If you would catchment contains six main rivers: the Colne, Ver, 4 Environment Agency Catchment Abstraction Management Strategy like to be sent a paper copy of Managing Water Abstraction please contact us at the following address: Water Resources Officer Apollo Court 2 Bishops Square Business Park St Albans Road West Hatfield Herts AL10 9EX Tel: 08708 506506 Fax: 01707 632500 Email: [email protected] Office hours: 9am–5pm Environment Agency Catchment Abstraction Management Strategy 5 2.0 The Colne CAMS contains the catchments of the Rivers Ver, Gade, Bulbourne, Chess and Misbourne all of which are tributaries of the River Colne which is itself a tributary of the River Thames. The Colne CAMS area 2.1 Introduction to CAMS area catchment, the topography slopes steeply away from the Chiltern Hills towards the south east. Within the An overview of the Colne CAMS area is shown in Map 1. easterly and southerly areas of the catchment, where The Colne CAMS covers an area of approximately 1014 the majority of the rivers converge or meet the River 2 km to the north-west of Greater London, and Colne, the topography is lower lying with a gentle slope incorporates parts of Bedfordshire and Hertfordshire towards the south. in the north, and Buckinghamshire and Middlesex in the south. The north and west sections of the The Colne catchment is dominated by Unconfined Chalk catchment border the southerly edge of the Chilterns which outcrops over a large area in the north of the and are predominantly rural whilst the central, south catchment. The upper reaches of the Colne’s main and east sections are more densely populated in the tributaries are dependent on the Unconfined Chalk as a urban areas of for example St Albans, Hemel source of groundwater for a constant water supply. Hempstead and Watford. Groundwater levels in the unconfined aquifer fluctuate seasonally in response to recharge from rainfall. 2.2 Hydrology and geology Where the Chalk aquifer is buried beneath a substantial clay cover, which forms an impermeable cap, this is The Colne CAMS catchment contains six main rivers and known as confined. Within the southern area of the their tributaries: the Colne, Ver, Gade, Bulbourne, catchment, London Clay overlies the Chalk. The Chess and Misbourne. These drain in a south-easterly Confined aquifer does not receive direct recharge and and southerly direction. They are typical chalk streams groundwater levels do not show the seasonal and their sources are subject to seasonal and annual fluctuations seen in the Unconfined aquifer. climatic variations. The Colne catchment receives an average annual rainfall of 716 mm. Groundwater moves south eastwards towards London and continues to flow in the Chalk as it extends under The River Colne rises near Hatfield and flows south the London Clay. westwards to Denham where it splits into a number of tributaries and drains that are interlinked in several The Chalk is the most significant aquifer of southern places before flowing into the Thames west of Staines, England and is of regional and national significance in upstream of Teddington Lock.