Groundwater Levels the Majority of Groundwater Sites in Wessex Are ‘Normal’ Or ‘Above Normal’ for the Time of Year
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Monthly water situation report Wessex Area Summary – February 2016 February rainfall was 136% of the long term average (LTA) but was distributed mainly in the first 8 days and then around mid month with the last half of the month being dry. The last 3 months have all had above average rainfall resulting in the 3 month total being 132% LTA. Rivers responded to the rainfall then were predominantly in recession from mid month. Soils remain wet close to capacity. Most groundwater sites have had significant recharge and are all normal or above for the time of year. Reservoir storage is almost at its maximum; Bristol water is at 99% of the total reservoir storage and Wessex Water is at capacity. Rainfall The start of the month was wet, 63% of Februarys rainfall fell within the first eight days. The rest of the month was mostly dry apart from a couple of wet days around the 17th. The average rainfall total across the Wessex Area was 136% of LTA (88 mm). Rainfall map and graph Soil Moisture Deficit The soil is wet, as expected for the time of year. The average soil moisture deficit across Wessex on 1 March 2016 was 1.08 mm, well below the LTA of 2.96 mm. SMD graph and maps River Flows River flows across the Wessex area were ‘exceptionally high’ around 6 February and the 18 February in response to the precipitation received at the start and middle of the month. Many of the stations in the north and along the southern edge of Wessex are ‘above normal’ or experiencing flows above the LTA. At month end all river flows in Wessex were in recession. River flow map and graphs Groundwater Levels The majority of groundwater sites in Wessex are ‘normal’ or ‘above normal’ for the time of year. Two of the sites have ‘exceptionally high’ values and represent the characteristics of the aquifer. Groundwater map and graphs Reservoir Storage Reservoir levels for Wessex are almost at full capacity and have been for the duration of February. Bristol water is 99% full and Wessex Water sites are 100%. Reservoir graphs All data are provisional and may be subject to revision. The views expressed in this document are not necessarily those of the Environment Agency. Its officers, servants or agents accept no liability for any loss or damage arising from the interpretation or use of the information, or reliance upon views contained herein. www.gov.uk/environment-agency © Environment Agency 2016 Flood Warnings and Alerts Area Flood Warnings Flood Alerts Wessex 9 ( 3 were coastal) 389 (339 were coastal) Sites Providing Stream Support River Site End of Month Status River Allen Wyke Down Off Chitterne Brook Codford Road Off Gussage Stream Gussage All Saints Off Devil’s Brook Dewlish WDX Off River Piddle Briantspuddle Off South Winterbourne Winterbourne Abbas Off Pimperne Stream Pimperne Off Watergates Stream Watergates On River Wylye Brixton Deverill Off River Wylye Kingston Deverill Off Rodbourne Brook Lower Stanton St. Quinton Off Tetbury Avon Tetbury Off Sherston Avon Stanbridge Off Luckington Brook Luckington Off Gauze Brooke Hullavington Off Charlton Stream Charlton Off Chalfield Brook South Wraxall Off Chalfield Brook Little Chalfield Off Abstraction Licences Subject to Cease or Restrict Catchment End of Month Status Hampshire Avon None Dorset Frome None Stour None Piddle None Bride None Wylye None Bristol Avon None Somerset 1 cease Glossary Author: Wessex Hydrology www.gov.uk/environment-agency © Environment Agency 2016 Rainfall Figure 1.1: Total rainfall for hydrological areas across England for the current month (February), the last three months, the last six months and the last 12 months, classed relative to an analysis of respective historic totals. Final NCIC (National Climate Information Centre) data based on the Met Office 5km gridded rainfall dataset derived from rain gauges (Source: Met Office © Crown Copyright, 2016). Provisional data based on Environment Agency 1km gridded rainfall dataset derived from Environment Agency intensity rain gauges. Crown copyright. All rights reserved. Environment Agency, 100026380, 2016. Return to Summary www.gov.uk/environment -agency © Environment Agency 2016 Above 100% LTA rainfall Below 100% LTA rainfall 1-Month Period for South West - Wessex NCIC 250% 200% 150% 100% Percentage of LTA 50% Feb Feb May May Nov Nov Aug 0% Aug - - - - - - - - 14 15 14 15 14 15 14 15 Figure 1.2: Monthly rainfall totals as a percentage of the 1961 – 1990 long term average. Produced using final and provisional NCIC (National Climate Information Centre) data. (Source: Met Office © Crown Copyright, 2016). Return to Summary www.gov.uk/environment -agency © Environment Agency 2016 Soil Moisture Deficit Less than historic minimum Greater than historic maximum ..... 1961-1990 long term average ── Latest data ── 2014 0 20 40 60 80 100 Soil moisture deficit (mm) deficit moisture Soil 120 140 160 Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Figure 2.1: Latest soil moisture deficit compared to previous year, maximum, minimum, and 1961 – 1990 long term average. Weekly MORECS data for real land use (Source: Met Office © Crown Copyright, 2016). Return to Summary www.gov.uk/environment -agency © Environment Agency 2016 Figure 2.2: Soil moisture deficits for week ending 01 February 2016. Top map shows actual soil moisture deficits (mm). Bottom map shows the difference (mm) of the actual from the 1961-90 long term average soil moisture deficits. MORECS data for real land use (Source: Met Office © Crown Copyright, 2016). Crown copyright. All rights reserved. Environment Agency, 100026380, 2016. Return to Summary www.gov.uk/environment -agency © Environment Agency 2016 River Flow Figure 3.1: Monthly mean river flows at indicator sites for February 2016, expressed as a percentage of the respective long term average and classed relative to an analysis of historic February monthly means (Source: Environment Agency). Crown copyright. All rights reserved. Environment Agency, 100026380, 2016. Return to Summary www.gov.uk/environment -agency © Environment Agency 2016 Exceptionally high Notably high Above normal Normal Below normal Notably low Exceptionally low ─── Latest data Tone at Bishops Hull Yeo at Pen Mill Ranking derived from data for the period 01/02/1961 to 31/12/2012 Ranking derived from data for the period 31/10/1963 to 31/12/2012 20 February mean flow 25 February mean flow 8.394 cumecs 18 5.078 cumecs 158% LTA 119% LTA 16 20 14 12 15 10 8 10 6 4 5 Daily Mean Flow (cumecs) Daily Mean Flow (cumecs) 2 0 0 29-Apr-15 29-Jun-15 29-Aug-15 29-Oct-15 29-Dec-15 29-Feb-16 29-Apr-15 29-Jun-15 29-Aug-15 29-Oct-15 29-Dec-15 29-Feb-16 Upper Brue at Lovington Bristol Avon at Bathford Ranking derived from data for the period 01/10/1964 to 31/12/2012 Ranking derived from data for the period 27/10/1969 to 31/12/2012 12 140 February mean flow February mean flow 3.813 cumecs 46.4 cumecs 121% LTA 120 130% LTA 10 100 8 80 6 60 4 40 Daily Mean Flow (cumecs) 2 Daily Mean Flow (cumecs) 20 0 0 29-Apr-15 29-Jun-15 29-Aug-15 29-Oct-15 29-Dec-15 29-Feb-16 29-Apr-15 29-Jun-15 29-Aug-15 29-Oct-15 29-Dec-15 29-Feb-16 Somerset Frome at Tellisford Bristol Avon at Great Somerford Ranking derived from data for the period 01/09/1961 to 31/12/2012 Ranking derived from data for the period 16/12/1963 to 31/12/2012 25 February mean flow February mean flow 7.738 cumecs 20 9.185 cumecs 126% LTA 154% LTA 20 15 15 10 10 5 5 Daily Mean Flow (cumecs) Daily Mean Flow (cumecs) 0 0 29-Apr-15 29-Jun-15 29-Aug-15 29-Oct-15 29-Dec-15 29-Feb-16 29-Apr-15 29-Jun-15 29-Aug-15 29-Oct-15 29-Dec-15 29-Feb-16 Middle Stour at Hammoon Dorset Frome at East Stoke Combined Ranking derived from data for the period 01/03/1968 to 31/12/2012 Ranking derived from data for the period 01/10/1965 to 31/12/2012 25 February mean flow February mean flow 60 14.001 cumecs 14.877 cumecs 124% LTA 136% LTA 20 50 40 15 30 10 20 5 Daily Mean Flow (cumecs) 10 Daily Mean Flow (cumecs) 0 0 29-Apr-15 29-Jun-15 29-Aug-15 29-Oct-15 29-Dec-15 29-Feb-16 29-Apr-15 29-Jun-15 29-Aug-15 29-Oct-15 29-Dec-15 29-Feb-16 Return to Summary www.gov.uk/environment -agency © Environment Agency 2016 Exceptionally high Notably high Above normal Normal Below normal Notably low Exceptionally low ─── Latest data Piddle at Baggs Mill Wylye at South Newton Ranking derived from data for the period 01/01/1964 to 31/12/2012 Ranking derived from data for the period 01/01/1967 to 31/12/2012 10 16 February mean flow February mean flow 8.584 cumecs 9.334 cumecs 9 196% LTA 14 120% LTA 8 12 7 10 6 5 8 4 6 3 4 2 Daily Mean Flow (cumecs) Daily Mean Flow (cumecs) 2 1 0 0 29-Apr-15 29-Jun-15 29-Aug-15 29-Oct-15 29-Dec-15 29-Feb-16 29-Apr-15 29-Jun-15 29-Aug-15 29-Oct-15 29-Dec-15 29-Feb-16 Upper Hampshire Avon at Amesbury Stour at Throop Ranking derived from data for the period 01/02/1965 to 31/12/2012 Ranking derived from data for the period 01/01/1973 to 31/12/2012 12 80 February mean flow February mean flow 6.477 cumecs 37.129 cumecs 107% LTA 70 149% LTA 10 60 8 50 6 40 30 4 20 Daily Mean Flow (cumecs) 2 Daily Mean Flow (cumecs) 10 0 0 29-Apr-15 29-Jun-15 29-Aug-15 29-Oct-15 29-Dec-15 29-Feb-16 29-Apr-15 29-Jun-15 29-Aug-15 29-Oct-15 29-Dec-15 29-Feb-16 Lower Hampshire Avon at Knapp Mill Washford at Beggearn Huish Ranking derived from data for the period 01/01/1975 to 31/12/2012 Ranking derived from data for the period 01/01/1967 to 31/12/2012 100 5.0 February mean flow February mean flow 37.9 cumecs 2.555 cumecs 90 4.5 100% LTA 170% LTA 80 4.0 70 3.5 60 3.0 50 2.5 40 2.0 30 1.5 20 1.0 Daily Mean Flow (cumecs) Daily Mean Flow (cumecs) 10 0.5 0 0.0 29-Apr-15