NRA South West 24 LOWER BRISTOL AVON CATCHMENT MANAGEMENT PLAN CONSULTATION REPORT NRA National Rivers Authority South Western Region March 1995 E n v ir o n m e n t Ag e n c y NATIONAL LIBRARY & INFORMATION SERVICE HEAD OFFICE Rio House, Waterside Drive, Aztec West. Almondsbury, Bristol BS32 4UD NRA Copyright Waiver This report is intended to be used widely and may be quoted, copied or reproduced in any way, provided that the extracts are not quoted out of context and that due acknowledgement is given to the National Rivers Authority. Published March 1995 ENVIRONMENT AGENCY 099886 FOREWORD This is the second Catchment Management Plan Consultation Report produced in North Wessex Area and it covers the Lower Bristol Avon downstream from Avoncliff Weir near Bradford-on-Avon together with all tributaries draining to the Avon below that point. We have dealt with the Avon catchment upstream of Avoncliff Weir in a separate management plan, for which a Consultation Report was published in June 1994 and an Action Plan published in March 1995. This report describes the physical features and factors such as geology and climate, for the Lower Bristol Avon. Importantly, we set out the NRA’s Vision for the catchment. We describe: • the activities in the catchment which affect the water environment and the uses made of water • the NRA’s objectives and targets for the water environment, described under five headings - water quality, water quantity, groundwater protection, physical features and flood defence • the state of the catchment is assessed in relation to the five categories of objectives. From this comparison we identify issues which need to be addressed by the NRA and others. These issues are intended to be the focus for consultation. In the treatment of the Upper and Lower Avon, there are many issues to consider, but in both catchments there are a small number which dominate discussion. In the Upper Avon, the abstraction of water for public supply from aquifers in the Malmesbury area is a major issue and long term solutions could have implications for the Lower Avon. In August 1994 the NRA completed a two year study which examined the impact on groundwater and river flows caused by these abstractions. Together with the water companies - Bristol Water and Wessex Water - we are working to improve the situation and this is covered in the Upper Bristol Avon Action Plan. There are, however, no easy solutions. If the measures being taken over the next few years prove insufficient, one option may be to substantially reduce abstractions from the Malmesbury area and replace them with equivalent increased abstraction from the lower reaches of the river. Such a proposal would be subject to conditions to ensure there was no adverse impact on the water environment. The Government sets out a strategy for meeting national current and forecast needs for aggregates and provides guidance to the Mineral Planning Authorities (MPA). As MPA the County Councils are then responsible for the preparation of Minerals Plans which meet the needs identified by the Government, while taking account of local factors such as the water environment. Individual quarrying activity is controlled through the Town and Country Planning legislation by the County Council. As a consultee on planning applications the NRA can therefore influence but not directly control such activity. Limestone quarrying in the Mendip Hills and the consequential effects on water resources is of major concern. The East Mendip hills include some of the largest stone quarries in Britain. In 1993, six quarries in that area produced about fifteen million tonnes of aggregate. Some 90% of this was Carboniferous Limestone taken from an important aquifer which supplies high-quality drinking water to over 600,000 people in Bristol, Avon and Somerset. Mineral quarrying removes the aquifer and in the process interrupts flows from boreholes, springs and streams, and causes water pollution. This is in direct conflict with the interests of water users who rely on the aquifer to provide sustainable 1 / sources of supply. One of our key objectives is the protection of groundwater from all types of threat, and the NRA publication Policy and Practice for the Protection of Groundwater sets out a framework by which this can be achieved. However, the issue of quarrying on the Mendips is one which goes far beyond the scope of this Report. We recognise the pressure that development puts on the water environment. The County and District Planning Authorities, though the preparation of Structure Plans, Minerals Plans, Waste Local Plans, District Wide Local Plans and the planning control system have a major role to play in helping to safeguard the water environment. Some rivers in the Lower Bristol Avon have suffered from the effects of past development and we will seek to ensure that Development Plans contain suitable policy options to allow environmental matters to be fully considered along with economic and social factors. This report identifies thirty seven issues affecting the Lower Bristol Avon. In addition to the concerns outlined above, it covers all aspects of the water environment which we need to consider if we are to succeed both in protecting the water environment and aspiring towards a goal of sustainable development. We invite your comments and welcome your views on our treatment of the catchment. If there are omissions from the list please let us know. After a three month public consultation period we will prepare an Action Plan based on the issues arising from the report and public consultation. CHRIS BIRKS Area Manager, North Wessex 2 YOUR VIEWS The Lower Bristol Avon Catchment Management Plan Consultation Report is the NRA’s initial analysis of the issues facing the catchment. We want to hear your views. * Have we identified all the issues? * Have we identified all the options for solutions? * Have you any comments on the issues and options listed? If so, we would like to hear from you. Comments on the Lower Bristol Avon Catchment Management Consultation Report are best sent in writing and should be received by 30 June 1995, To comment, please write to: Alan Turner North Wessex Area Catchment Planner NRA South Western Region Rivers House East Quay Bridgwater Somerset TA6 4YS Tel: Bridgwater (01278) 457333 Ext 4765 Environment Agency information Centre Head Office Class N o Accession No .. .B. ,A.X V. THE NATIONAL RIVERS AUTHORITY The NRA’s mission and aims are as follows: We will protect and improve the water environment by the effective management of water resources and by substantial reductions in pollution. We will aim to provide effective defence for people and property against flooding from rivers and the sea. In discharging our duties we will operate openly and balance the interest of all who benefit from and use rivers, groundwaters, estuaries, and coastal waters. We will be businesslike, efficient and caring towards our employees. AIMS • Achieve a continuing overall improvement in the quality of rivers, estuaries and coastal waters, through the control of pollution. • Manage water resources to achieve the right balance between the needs of the environment and those of the abstractors. • Provide effective defence for people and property against flooding from rivers and the sea. • Provide adequate arrangements for flood forecasting and warning. • Maintain, improve and develop fisheries. • Develop the amenity and recreational potential of inland and coastal waters and associated lands. • Conserve and enhance wildlife, landscape and archaeological features associated with inland and coastal waters of England and Wales. • Improve and maintain inland waters and their facilities for use by the public where the NRA is the navigation authority. • Ensure that dischargers pay the costs of the consequences of their discharges, and, as far as possible, to recover the costs of water environment improvements from those who benefit. • Improve public understanding of the water environment and the NRA’s work. • Improve efficiency in the exercise of the NRA’s functions and to provide challenge and opportunity for employees and show concern for their welfare. LOWER BRISTOL AVON CATCHMENT MANAGEMENT PLAN CONTENTS PAGE NUMBER FOREWORD A YOUR VIEWS 3 NRA MISSION AND AIMS STATEMENT 4 LIST OF APPENDICES 7 1.0 INTRODUCTION 1.1 The National Rivers Authority 9 1.2 Scope and Process of Catchment Management Planning 9 1.3 Limitations 11 2.0 CATCHMENT DESCRIPTION/OVERVIEW 2.1 Introduction 13 2.2 Climate 14 2.3 Hydrology 17 2.4 Geology, soils, hydrogeology 18 2.5 River water quality 21 2.6 Catchment facts 22 2.7 NRA Vision 23 3.0 CATCHMENT USES, ATTRIBUTES AND ACTIVITIES 3.1 River corridor and catchment land use 25 3.2 Town and Country planning strategy 31 3.3 Catchment urbanisation 39 3.4 Catchment drainage 43 5 PAGE NUMBER 3.5 Water abstraction and supply 51 3.6 Mineral Extraction and Waste Disposal 57 3.7 Effluent disposal 67 3.8 Fisheries - game and coarse 73 3.9 Conservation, landscape, wildlife and archaeology 79 3.10 Water based recreation and amenity 89 4.0 OBJECTIVES/TARGETS 4.1 Water quality targets 95 4.2 Water quantity objectives 100 4.3 Groundwater protection 103 4.4 Physical features objectives 107 4.5 Flood defence objectives 111 5.0 STATE OF THE CATCHMENT AND CATCHMENT ISSUES 5.1 State of catchment water quality 115 5.2 State of catchment water quantity 129 5.3 Physical features 139 5.4 Flood defence 150 6.0 ISSUES LIST 154 6 APPENDICES 1 Standards For The Five River Ecosystem Use Classes 2 EC Directive