Monthly Water Situation Report Lincolnshire and Northamptonshire Area
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Monthly water situation report Lincolnshire and Northamptonshire Area Summary – August 2021 After near average rainfall in July, August was drier than average. This saw the soil moisture deficit increase and flows in rivers decrease. The wet winter means that groundwater levels are normal or above normal and this has supported the baseflows in the groundwater fed rivers but some of the runoff dominated rivers are now classified as below normal Rainfall Lincolnshire and Northamptonshire Area received an average of 26.1mm during August, 44% of the long term average. The lowest rainfall was in the Witham to Chapel Hill hydrological area with 22.5mm, 37% of the long term average and the highest was in the Louth Grimsby and Ancholme hydrological area with 31.6mm, 52% of the long term average. Soil Moisture Deficit/Recharge In response to the dry August soil moisture deficits are either normal or above normal for the time of year. River Flows River flows have been falling during August particularly in the runoff dominated river Welland and Nene catch- ments. Flows at 8 out of the 10 sites monitored are classified as normal for August with Brampton branch of the River Nene at St Andrews Mill and the Ashley on the River Welland classified as below normal. Groundwater Levels Groundwater levels fell in line with the seasonal trend during August but because of the wetter than average win- ter recharge period these are classified as either normal or above normal for the time of year Reservoir Storage/Water Resource Zone Stocks All reservoirs are near or above their normal operating curves. Environmental Impact There have been 2 additional cessation notice issued for the River Bain during August. The River Witham to River Ancholme Transfer has been operating during August and the River Slea augmentation was turned on at the end of August. No fluvial Flood Alerts or Flood Warning were issued during August. Forward Look Probabilistic ensemble projections for river flows at key sites September 2021: There is a reduced likelihood of exceptionally low flows this September in the River Nene. December 2021: There is an increased probability of flows below the normal range this December. Probabilistic ensemble projections for groundwater levels in key aquifers September 2021: Groundwater levels are project to be in the normal range in both the chalk and oolitic lime- stone aquifers this September. March 2022: There is reduced probability of groundwater levels being lower than below normal next March. Author: Hydrology and Operations Contact details: 03708 506506 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. © Environment Agency 2021 Rainfall August 2021 P a g e | 2 1-Month Period for Louth Grimsby and Ancholme 1-Month Period for Steeping Great Eau and Long Eau 100 120 90 100 80 70 80 60 50 60 40 40 30 20 20 10 0 0 Oct-20 Jul-21 Oct-20 Jul-21 Sep- Nov- Dec- Jan- Feb- Mar- Apr-21 May- Jun- Aug- Sep- Nov- Dec- Jan- Feb- Mar- Apr-21 May- Jun- Aug- 21 21 21 21 21 21 21 21 21 21 20 20 20 20 20 20 21 21 1-Month Period for Witham to Chapel Hill 1-Month Period for South Forty Foot and Hobhole 120 120 100 100 80 80 3 | 60 60 40 40 P a g e 20 20 0 0 Oct-20 Jul-21 Oct-20 Jul-21 Sep- Nov- Dec- Jan- Feb- Mar- Apr-21 May- Jun- Aug- Sep- Nov- Dec- Jan- Feb- Mar- Apr-21 May- Jun- Aug- 21 21 21 21 21 21 21 21 21 21 20 20 20 20 20 20 21 21 1-Month Period for Upper Welland and Nene 1-Month Period for Lower Welland and Nene 140 140 120 120 Environment Agency 2021 Agency Environment 100 100 © 80 80 60 60 40 40 20 20 Long Term Rainfall Average in Millimetres 0 0 Oct-20 Jul-21 Oct-20 Jul-21 Sep- Nov- Dec- Jan- Feb- Mar- Apr-21 May- Jun- Aug- Sep- Nov- Dec- Jan- Feb- Mar- Apr-21 May- Jun- Aug- 21 21 21 21 21 21 21 21 21 21 20 20 20 20 20 20 21 21 Total Rainfall in Millimetres Soil Moisture Deficit Ancholme Grimsby Louth Steeping Great Eau and Long Eau Ranking derived from data for the period Jan-1961 to Dec- Ranking derived from data for the period Jan-1961 to Dec- 2012 2012 0 0 20 20 40 40 60 60 80 80 SMD (mm) SMD (mm) 100 100 120 120 140 140 160 Sep Oct Nov Dec Jan Feb Mar Apr May Jun Jul Aug Sep Sep Oct Nov Dec Jan Feb Mar Apr May Jun Jul Aug Sep Witham to Chapel Hill South Forty Foot and Hobhole Ranking derived from data for the period Jan-1961 to Dec- Ranking derived from data for the period Jan-1961 to Dec- 2012 2012 0 0 20 20 40 40 60 60 80 80 100 SMD (mm) SMD (mm) 120 100 140 120 160 140 180 Sep Oct Nov Dec Jan Feb Mar Apr May Jun Jul Aug Sep Sep Oct Nov Dec Jan Feb Mar Apr May Jun Jul Aug Sep Upper Welland and Nene Lower Welland and Nene Ranking derived from data for the period Jan-1961 to Dec- Ranking derived from data for the period Jan-1961 to Dec- 2012 2012 0 0 20 20 40 40 60 60 80 80 SMD (mm) SMD (mm) 100 100 120 120 140 140 160 Sep Oct Nov Dec Jan Feb Mar Apr May Jun Jul Aug Sep Sep Oct Nov Dec Jan Feb Mar Apr May Jun Jul Aug Sep P a g e | 4 © Environment Agency 2021 River Flow August 2021 P a g e | 5 © Environment Agency 2021 Exceptionally high Notably high Above normal Normal - - - - Max Below normal Notably low Exceptionally low ─── Latest data - - - - Min Louth Weir, LUD Rase Bishopbridge, ANCHOLME Ranking derived from data for the period Jul-1968 to Dec-2017 Ranking derived from data for the period Jun-1967 to Dec-2012 2.0 2.5 1.8 1.6 2.0 1.4 1.2 1.5 1.0 0.8 1.0 Flow (cumecs)Flow Flow (cumecs)Flow 0.6 0.4 0.5 0.2 0.0 0.0 Nov-20 Jan-21 Mar-21 May-21 Jul-21 Sep-21 Nov-20 Jan-21 Mar-21 May-21 Jul-21 Sep-21 Claypole, UPPER WITHAM Partney, LYMN & STEEPING Ranking derived from data for the period May-1959 to Dec-2017 Ranking derived from data for the period May-1962 to Dec-2012 3.0 10 2.5 8 2.0 6 1.5 4 1.0 Flow (cumecs)Flow (cumecs)Flow 2 0.5 0 0.0 Nov-20 Jan-21 Mar-21 May-21 Jul-21 Sep-21 Nov-20 Jan-21 Mar-21 May-21 Jul-21 Sep-21 Fulsby and Fulsby Model combined, BAIN Langworth, BARLINGS EAU Ranking derived from data for the period Oct-1962 to Dec-2012 Ranking derived from data for the period Jul-1980 to Dec-2012 6.0 10 9 5.0 8 7 4.0 6 3.0 5 4 2.0 Flow (cumecs)Flow Flow (cumecs)Flow 3 2 1.0 1 0.0 0 Nov-20 Jan-21 Mar-21 May-21 Jul-21 Sep-21 Nov-20 Jan-21 Mar-21 May-21 Jul-21 Sep-21 Ashley, WELLAND Kates Bridge plus King Street, GLEN Ranking derived from data for the period Oct-1970 to Dec-2012 Ranking derived from data for the period Jan-1991 to Dec-2012 9 8.0 8 7.0 7 6.0 6 5.0 5 4.0 4 3.0 3 Flow (cumecs)Flow (cumecs)Flow 2 2.0 1 1.0 0 0.0 Nov-20 Jan-21 Mar-21 May-21 Jul-21 Sep-21 Nov-20 Jan-21 Mar-21 May-21 Jul-21 Sep-21 P a g e | 6 © Environment Agency 2021 Exceptionally high Notably high Above normal Normal - - - - Max Below normal Notably low Exceptionally low ─── Latest data - - - - Min Upton Mill Total, NENE (KISLINGBURY BRANCH) St.Andrews total, NENE - BRAMPTON BRANCH Ranking derived from data for the period Jan-1970 to Dec-2017 Ranking derived from data for the period Jan-1970 to Dec-2012 8 7.0 7 6.0 6 5.0 5 4.0 4 3.0 3 Flow (cumecs)Flow Flow (cumecs)Flow 2.0 2 1 1.0 0 0.0 Nov-20 Jan-21 Mar-21 May-21 Jul-21 Sep-21 Nov-20 Jan-21 Mar-21 May-21 Jul-21 Sep-21 P a g e | 7 © Environment Agency 2021 Groundwater Levels August 2021 Exceptionally high Notably high Above normal Normal - - - - Max Below normal Notably low Exceptionally low ─── Latest data - - - - Min Dunholme Road, Scothern Castlethorpe Bridge Ranking derived from data for the period Nov-1979 to Dec-2017 Ranking derived from data for the period Nov-1996 to Dec-2017 23 3.0 22 2.5 21 2.0 20 19 1.5 18 1.0 17 0.5 Level (mAOD) Level Level (mAOD) Level 16 0.0 15 14 -0.5 13 -1.0 Nov-18 Mar-19 Jul-19 Nov-19 Mar-20 Jul-20 Nov-20 Mar-21 Jul-21 Nov-18 Mar-19 Jul-19 Nov-19 Mar-20 Jul-20 Nov-20 Mar-21 Jul-21 P a g e | 8 © Environment Agency 2021 Exceptionally high Notably high Above normal Normal - - - - Max Below normal Notably low Exceptionally low ─── Latest data - - - - Min Leasingham Exploratory - LINCS LIMESTONE Grange Farm, Aswarby - LINCS LIMESTONE Ranking derived from data for the period Sep-1972 to Dec-2017 Ranking derived from data for the period Dec-1970 to Dec-2017 22 23 20 21 19 18 17 16 15 14 13 12 11 Level (mAOD) Level (mAOD) Level 10 9 8 7 6 5 Nov-18 Mar-19 Jul-19 Nov-19 Mar-20 Jul-20 Nov-20 Mar-21 Jul-21 Nov-18 Mar-19 Jul-19 Nov-19 Mar-20 Jul-20 Nov-20 Mar-21 Jul-21 Greatford Hanthorpe - LINCS LIMESTONE Ranking derived from data for the period Jul-1974 to Dec-2017 Ranking derived from data for the period Jul-1972 to Dec-2017 20 17 18 15 16 13 14 11 12 9 10 7 8 5 Level (mAOD) Level Level (mAOD) Level 6 3 4 1 2 -1 0 Nov-18 Mar-19 Jul-19 Nov-19 Mar-20 Jul-20 Nov-20 Mar-21 Jul-21 Nov-18 Mar-19 Jul-19 Nov-19 Mar-20 Jul-20 Nov-20 Mar-21 Jul-21 Grainsby - LINCS CHALK Horkstow Road, Barton-upon-Humber Ranking derived from data for the period Oct-1977 to Dec-2017 NORTH LINCS CHALK Ranking derived from data for the period Apr-1980 to Dec-2017 24 22 9 20 18 7 16 14 5 12 3 Level (mAOD) Level Level (mAOD) Level 10 8 1 6 4 -1 Nov-18 Mar-19 Jul-19 Nov-19 Mar-20 Jul-20 Nov-20 Mar-21 Jul-21 Nov-18 Mar-19 Jul-19 Nov-19 Mar-20 Jul-20 Nov-20 Mar-21 Jul-21 P a g e | 9 © Environment Agency 2021 Reservoir Stocks August 2021 Rutland Pitsford 100 100 90 90 80 80 70 70 60 60 50 50 40 40 30 30 Percentage of live live capacitiy of Percentage Percentage of live live capacitiy of Percentage 20 20 10 10 1996-1997 0 0 Jan Mar May Jul Sep Nov Jan Mar May Jul Sep Nov Jan Mar May Jul Sep Nov Jan Mar May Jul Sep Nov Combined Ravensthorpe and Hollowell Covenham 100 100 90 90 80 80 70 70 60 60 50 50 40 40 30 30 Percentage of live live capacitiy of Percentage Percentage of live live capacitiy of Percentage 20 20 10 10 0 0 Jan Mar May Jul Sep Nov Jan Mar May Jul Sep Nov Jan Mar May Jul Sep Nov Jan Mar May Jul Sep Nov Normal Operating Curve ------ Drought Curve ---- 1995-1996 - - - - 2020-21 ------ P a g e | 10 © Environment Agency 2021 Forward Look – River Flows Exceptionally high or low levels are those which would typically occur 5% of the time within the historic record.