ENVIRONMENT AGENCY SOUTH WEST REGION 1997 ANNUAL HYDROMETRIC REPORT Environment Agency Manley House, Kestrel Way Sowton Industrial Estate Exeter EX2 7LQ Tel 01392 444000 Fax 01392 444238 GTN 7-24-X 1000 Foreword The 1997 Hydrometric Report is the third document of its kind to be produced since the formation of the Environment Agency (South West Region) from the National Rivers Authority, Her Majesty Inspectorate of Pollution and Waste Regulation Authorities. The document is the fourth in a series of reports produced on an annua! basis when all available data for the year has been archived. The principal purpose of the report is to increase the awareness of the hydrometry within the South West Region through listing the current and historic hydrometric networks, key hydrometric staff contacts, what data is available and the reporting options available to users. If you have any comments regarding the content or format of this report then please direct these to the Regional Hydrometric Section at Exeter. A questionnaire is attached to collate your views on the annual hydrometric report. Your time in filling in the questionnaire is appreciated. ENVIRONMENT AGENCY Contents Page number 1.1 Introduction.............................. .................................................... ........-................1 1.2 Hydrometric staff contacts.................................................................................. 2 1.3 South West Region hydrometric network overview......................................3 2.1 Hydrological summary: overview 1996............................................................6 2.2 1995 Monthly hydrological summary............................ :.......... .................... 15 2.3 Notable flows during 1996................................................................................ 20 3 Surface water gauging stations........................................................................ 31 3.1 Introduction.......................................................................................................... 31 3.2 Station listings and summary statistics...........................................................31 4 Groundwater stations ..........................................................................................80 4.1 Introduction..........................................................................................................80 4.2 Station listings...................................................................................................... 80 5 Rainfall stations................... .............................................................................122 5.1 Introduction........................................................................................................122 5.2 Station listings and summary statistics.........................................................122 6 Standard reporting options from current systems...................................... 171 6.1 Introduction........................................................................................................171 6.2 . Surface water................. ....................................................................................171 6.3 Groundwater..................................................,...................................................234 6.4 Rainfall.................................................................................................................234 7 Other sources of information..........................................................................234 7.1 Scope....................................................................................................................234 7.2 M ORECS.......................:....................................................................................234 7.3 Reservoir storage’s...;........... .................................... .......................................234 7.4 Water situation reports.............!....................................................................... 235 List of Tables 1 South West Region Statistical Summary..........................................................4 2 Areal rainfall totals in South West Region for 1995/1996............................ 8 3 Comparison of 1996 mean monthly flows with long term averages... 11/12 4 Surface water gauging stations - currently operating sites......................... 33 4b Chart Recorders-Level Only S ites...................................................................41 5 Surface water gauging stations * further summary statistics....................... 43 List of Tables (cont.) 5a Gauging station classification listing............................................................... 72 5b Special investigation sites........................................ :......................................81 6 Groundwater stations - currently operating sites ......................................... 82 6a Groundwater stations - historic sites..............................................................94 7 Rainfall stations - currently operating sites & summary statistics...........123 7a Rainfall stations - historic sites.......................................................................136 List of Figures 1 Spatial variation in annual areal rainfall totals................................................. 5 2a Cumulative regional rainfall totals for selected years...................................... 9 2b Spatial variation in rainfall totals during the 1995/96 winter.......................10 2c Variation in soil moisture deficits during 1996.............................................. 13 3 Variation in reservoir storages during 1996............................................... 14 4 Map to show location of current surface water gauging stations................ 42 5 Map to show location of current groundwater stations............................. 121 6 Map to show location of current rainfall stations.......................................122 7 Devon & Cornwall surface flow annual reports and flow duration curves........................!..................................................................................... 172 8 Examples of Devon & Cornwall R143 annual summary and R106 monthly summary reports.............;............................. ................................ 196 9 Wessex monthly mean summary reports and flow duration curves........198 1.1 Introduction This report is the fourth document of its kind to cover all the hydro metric stations in the South West Region. The report reviews the weather conditions and notable hydrological events during 1997. The current site listings of surface water gauging, groundwater and rainfall stations present reference information for each site, together with the Area offices responsible for data collection and processing. Summary statistics for 1997 and updated long term averages have also been compiled for each current station. Hydrometric staff contacts within each area and regional office are listed for information. Only sites where hydrometric staff are responsible for data collection and processing have been included in this report. An additional feature of the 1997 annual report is the inclusion of site listings and location maps for historic groundwater and rainfall sites. The location maps have been produced using the G.I.S. system Arcview. The themes for current gauging stations and both current and historic groundwater and rainfall sites are to be stored on the G.I.S. servers in order to be available to G.I.S. users and those with access to Mapexplorer across the region. The data archiving systems and standard reports for data analysis, and presentation are briefly outlined to help staff tailor their information requests. Convergence of systems has continued with all Areas within the South West region using Hydrolog, Rairiark and Gaugeman. All Areas will be using the Gaugeman systems and a common spot flow gaugings database (SFM) will store current meter gaugings from all 4 Areas and be available to all users with Access 97. Additional hydrometric reports and sources of information are.also included for reference in section 6. A Service Level Agreement for the provision of hydrometric data is in operation between hydrometric staff and the Client Board. The Service Level Agreement specifies the sites at which data will be available on the archives with set timescales and also specifies the accuracy of the data from sites. Further information relating to the SLA is available from the Senior Hydrologist and members of the Client Board whose chairman is Bill Grigg. The regional hydrometric section, has compiled this annual hydrometric report with support from Area hydrometric colleagues, notably with the compilation and verification . of the hydrometric site inventories. 1.2 Hydrometric Staff Contacts The Hydrometric staff in the South West Region are listed below in alphabetical order by office. The principal points of contact in each office are the Team Leaders of each Area Water Resources section and the Senior Hydrologist at the Regional office. Water 1 Resources staff involved in hydrometry are listed alphabetically in each Area Water Resources section. Area and Regional Hvdrometric Contacts, Cornwall Area: Graeme Boyce Water Resources Team Leader Roger Bailey Water Resources Officer Stephen Marks Hydrologist Ian Barker Hydrometric Officer Adam Gilbert Hydrometric Officer Chris Ridge Hydrometric Officer Gill Skinner Water Resources Licensing Assistant