y , D A O f n i ENVIRONMENT AGENCY E n v i r o n m e n t SOUTH WEST REGION A g e n c y 1998 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 En v ir o n m e n t Ag e n c y NATIONAL LIBRARY & INFORMATION SERVICE SOUTH WEST REGION Manley House, Kestrel Way, Exeter EX 2 7LQ Ww+ 100 •1 -T ' C o p y V ENVIRONMENT AGENCY SOUTH WEST REGION 1998 ANNUAL HYDROMETRIC REPORT Environment Agency Manley House, Kestrel Way Sowton Indutrial Estate Exeter EX2 7LQ Tel: 01392 444000 Fax: 01392 333238 ENVIRONMENT AGENCY uiiiiiiiiiin047228 TABLE OF CONTENTS HYDROMETRIC SUMMARY AND DATA FOR 1998 Page No. 1.0 INTRODUCTION........................................................................... ................................................. 1 1.1 Hydrometric Staff Contacts............................................................................................................1 1.2 South West Region Hydrometric Network Overview..............................................................3 2.0 HYDROLOGICAL SUMMARY.................................................................................................... 6 2.1 Annual Summary 1998....................................................................................................................6 2.2 1998 Monthly Hydrological Summary........................................................................................ 7 3.0 SURFACE WATER GAUGING STATIONS............................................................................ 12 3.1 Network Overview.......................:.................................................................................................12 3.2 Station Listings and Summary Statistics...................................................................................12 4.0 GROUNDWATER STATIONS....................................................................................................13 4.1 Network Overview......................................................................................................................... 13 4.2 Station Listings...............................................................................................................................13 5.0 RAINFALL STATIONS................................................................................................................13 5.1 Network Overview.........................................................................................................................13 5.2 Station Listings and Summary Statistics..................................................................................14 6.0 STANDARD REPORTING OPTIONS.......................................................................................14 6.1 Introduction......................................................................................................................................14 6.2 Surface W ater.........................................................................................................;.......................14 6.3 Groundwater....................................................................................................................................15 6.4 Rainfall............................................................................,...........*................................................... 15 7.0 ADDITIONAL SOURCES OF INFORMATION.......................................................... ..........15 7.1 Scope.................................................................................................................................................15 7.2 M.O.R.E.C.S...................................................................................................................................15 7.3 Reservoir Storages.........................................................................................................................16 7.4 Water Situation Reports...............................................................................................................16 TABLES FIGURES MAPS TABLES 1.0 South West Region Statistical Summary.......................................................................................4 2.0 Comparison of 1998 Mean Monthly Flows with Long-term averages..................................17 3.0 Surface Water Gauging Stations - Currently Operating Sites................................................. 19 3.1 Chart Recorders-Level Only Sites............................................................................................... 28 3.2 Surface Water Gauging Stations - Further Summary Statistics.............................................. 29 4.0 Special Investigation Sites............................................................................................................58 4.1 Groundwater Stations - Currently Operating Sites...................................................................59 5.0 Areal Rainfall Totals in South West Region for 1997/1998....................................................71 5.1 Rainfall Stations - Currently Operating Sites & Summary Statistics....................................72 FIGURES 1.0 Spatial Variation in Annual Areal Rainfall Totals......................................................................5 2.0 Variation in Soil Moisture Deficits during 1998.......................................................................84 3.0 Variation in Reservoir Storages during 1998.................................:..........................................85 4.0 Devon & Cornwall Surface Flow Annual Reports and Flow Duration Curves....................86 4.1 Examples of Devon & Cornwall R143 Annual Summary and R106 Monthly Summary Reports........................................................................................................110 4.2 Wessex Monthly Mean Summary Reports and Flow Duration Curves...............................112 MAPS 1 Map to show Location of Current Surface Water Gauging Stations....................................148 2 Map to show Location of Current Groundwater Stations......................................................149 3 Map to show Location of Current Rainfall Stations............................................................... 150 Foreword The 1998 Hydrometric Report is the fourth document of its kind to be published since the Environment Agency assumed responsibility for hydrometric data in the South West Region. The document is one of a series of reports produced on an annual basis, by the staff of the Environment Agency. The report is designed to act as a reference for the year and to give an indication of the type and availability of data that can be obtained from established measurement stations. The document provides listings of river level and flow stations, groundwater boreholes and rainfall gauges maintained by the region, with maps to identify their locations. Only sites where hy drome trie staff are responsible for data collection and processing have been included in this report. A brief hydrometric review, list of key hydrometric contacts and details of reporting options available to users, are also covered, to help staff tailor information requests. The hydrometric data quoted in the report represents the combined efforts of the hydrometric field staff, who maintain the stations and undertake vital calibrations and staff involved with processing and archiving the data for future use. Hydrometric data can be provided to members of the public and external organisations by writing to the Environment Agency or by telephone request. Requests or advice regarding the provision of data not included within this report should be directed to Area hydrometric staff or to the Regional Hydrological section at Exeter. Please forward any comments regarding the content or format of this report to Tamsin Howels (Telephone 01392-44-2086) or Keith Garrett (Telephone 01392 442079). 1.0 INTRODUCTION Feedback from the 1997 Annual Report evaluation questionnaires suggest that some content and structural changes are required in order to meet new challenges. Changes to the report will be programmed into a running schedule over the next few years, a chapter will summarise this strategy in the 1999 report. Due to the varying data requirements of report recipients, it was concluded that the document should be divided into an historic reference catalogue, delivered every other year, and an annual summary. The 1998 Report focuses on currently operating sites only. The reference catalogue is to be developed for the 1999 issue, with a view to including additional site summary data and closed surface water gauging site listings and locational maps. Additional features of subsequent reports are to include isohyetal rainfall charts, notable flooding/low flow events, catchment boundaries and the availability of naturalised flow records. The ‘Notable Flows’ list has been removed from the 1998 report, as has the gauging station classification list which at present has a low level of accuracy. A number of new initiatives were implemented in 1998, including the migration of hydrometric site reference data into the Geographical Information System (G.I.S.) Arcview. This data is available to G.I.S. users across the Region and staff with access to MapExplorer. Convergence of Hydrolog, Rainark and Gaugeman archiving systems continued, regional accessibility of Hydrometric information has further been enhanced by the migration of Hydrolog