Water Situation Report Midlands Region

Monthly water situation report Midlands Region

Summary – December 2015

Rainfall – Most Midlands hydrological areas received ‘notably high/above normal’ amounts of rainfall. Soil Moisture Deficit – Normal soil moisture deficit for December. Soils are saturated across much of the Midlands. Deficits are limited to eastern parts of the region. River Flows – River flows across the Midland are ‘normal’ or greater than normal. Groundwater Levels – Most groundwater monitoring sites were ‘normal’ with the exception of Hodhill and Four Crosses (‘below normal’) and Ram Hall (‘notably high’). Reservoir Storage – At the end of December all reservoir levels were above average storage, with the exception of Charnwood (59.6%), Dove (66.5%). Carsington is also near its average storage.

Our former Midlands region is split into three areas: Midlands West is now Shropshire, Herefordshire, Worcestershire and Gloucestershire (SHWG) Area, Midlands Central is now Staffordshire, Warwickshire and West Midlands (SWWM) Area and Midlands East is now Derbyshire, Nottinghamshire and Leicestershire (DNL) Area.

Rainfall

In December rainfall totals ranged from 112% to 209% of long term average. The greatest rainfall totals were over western parts of the region (Welsh Mountains (298mm), Middle/lower Severn main channel (115.3- 126.1mm), Wye (164.9mm)) and on the high ground of the Derwent (139.7mm).

Relative to long term average (LTA) most hydrological areas received greater than average rainfall. The only exceptions were the Dove (100.1mm) and Soar (72.6mm) catchments which had ‘normal’ amounts of rain. ‘Notably high’ rainfall amounts fell in southern parts of the Midlands (Wye (164.9mm), Lower Severn (115.3mm) and Avon (93.2mm)). ‘Exceptional high’ rainfall amounts occurred in the Welsh mountains (298.7mm) with twice the LTA.

Rainfalls over the last 3 and 6 months periods were ‘normal’ or greater than normal across the Midlands. The wettest areas occurring over the Welsh mountains, Lower Severn, Avon, Wye and Derwent.

Please refer to Midlands Rainfall Map and Midlands Rainfall Charts

Soil Moisture Deficit

Soil moisture deficit across the Midlands is currently minimal. This saturation of soil is typical of December. Only the eastern parts of the region are shown to be non-saturated, the maximum deficit (11-40mm) occurring in the Trent lowlands.

Please refer to the SMD Map and the Midlands SMD Charts

River Flows

Most of the River Severn catchment had flows which were ‘above normal’ or greater. Exceptional flows occurred on the Tanat at Llanyblodwel, Severn at Bewdley and also on the Wye at Redbrook. The Trent catchment had mostly ‘normal flows’ with the exception of ‘above normal’ flows on the Derwent at Derby St Mary’s.

Please refer to Midlands River Flow Map and Midlands River Flow Charts

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 2015

Water Abstraction Restrictions (as of 07-1-2016)

Abstraction Licence Restrictions Rivers & (Stations) Restricted Thresholds Crossed

SHWG 0

SWWM 0

DNL 0

Table 1. Water abstraction licence restrictions as of 07-01-2016. Please note: The No. of thresholds crossed does not refer to the individual numbers of abstraction licences restricted. It instead relates to the number of Hands off flow thresholds that are currently in force at time of print (i.e. Primary, Secondary etc.).

River Severn Operations (as of 08-10-2015)

The River Severn is regulated to maintain a minimum flow at Bewdley gauging station. This ensures sufficient water flows along the river to support environmental and water supply requirements. Flows at Bewdley are monitored between April and mid-October and regulation instigated when flows drop below a specific threshold at Bewdley.

The end of the regulation season was confirmed on 17th November 2015 following 63 days of regulation.

River Wye Operations (as of 08-10-2015)

Flows in the River Wye at Redbrook were below the regulation threshold at the beginning of November and so regulation releases were made from the Elan reservoir up until 1 November 2015. The River Wye Regulation ceased on 2 November 2015 as the river returned above the 1209 Ml/d threshold under the winter operating conditions.

Groundwater Levels

Most groundwater monitoring sites were ‘normal’, with the exception of ‘Below normal’ levels at Hodhill (Magnesian Limestone), Four crosses (Sherwood Sandstone) and ‘notably high’ level at Ram Hall.

During December winter recharge occurred at Anthony’s Cross, Hodhill Farm, Ram Hall, Rider Point and more minor increases in level at Four Crosses and Heathlanes.

Please refer to Midlands Groundwater Map and Midlands Groundwater Charts

Reservoir Storage

At the end of December all reservoirs levels were above average storage, with the exception of Charnwood (59.6%) and Dove (66.5%). Carsington & Ogston (76%) is also near (<1%) its average storage.

Clywedog, Vyrnwy, Derwent system, Tittesworth and Elan are at/or near 100% full. All other reservoirs increased in storage during December except Carsington & Ogston which had little change.

Please refer to Midlands Reservoir Charts

Environmental Impact

There are currently no flow compensation schemes in operation

Flood Alerts / Warnings

Current Flood watch/ warning status in your area can be obtained by visiting the Environment Agency Website

Weather Outlook

For an up-to-date weather outlook for the month of January in your area please visit the Met Office Website

Author: Paul A Clark Contact details: 02030252823

Regional Coverage

Please refer to map below, illustrating both the Midlands regional boundary and the Severn/ Trent hydrological boundary.

Key

---- Severn & Trent Hydrological Boundary ___ Midlands Region Boundary (including West, Central and East area boundaries)

We currently do not supply a Welsh version of the Midlands Water Situation Report. If you would like to express an interest in receiving this report in Welsh please contact us.

Midlands Hydrological Areas

Figure 1: This map shows the 12 hydrological areas that make up the Midlands region Please use the link to see Natural Resources Wales Water Situation Report.

Rainfall Map for December 2015

Figure 2. Total rainfall for hydrological areas across England for the current month, the last three months, the last six months, and the last 12 months, classed relative to an analysis of respective historic totals. Final and provisional NCIC (National Climate Information Centre) data based on the Met Office 5km gridded rainfall dataset derived from rain gauges (Source: Met Office © Crown Copyright, 2015). Crown copyright. All rights reserved. Environment Agency, 100026380, 2015.

Total Rainfall Total Rainfall Region/ Area (mm) LTA (mm) Region/ Area (mm) LTA (mm) Midlands region 102.6 71.8 Lower Severn 115.3 73.2 DNL 85.9 66.5 Upper Trent 91.5 73.4 SWWM 95.9 70.9 Tame 96.4 66.8 SHWG 119.4 76.1 Dove 100.1 89.7 Welsh Mountains 298.7 142.9 Derwent 139.7 101.5 Shropshire Plains 96.4 70.2 Soar 72.6 58.9 Mid Severn/ Teme 126.1 81.4 Lower Trent 71.2 57.3 Avon 93.2 63.3 Lower Wye 164.9 90.2 Table 2. December average rainfall totals and December LTA figures in 12 Environment Agency Hydrological areas across the Midlands region, using NCIC data. (Source: Met Office © Crown Copyright. All rights reserved. Environment Agency, 100026380, 2015).

Midlands Rainfall Charts

Above average rainfall Below average rainfall 1-Month Period for Welsh Uplands 1-Month Period for Shropshire plains

250% 250%

200% 200%

150% 150%

100% 100%

50% 50% Nov Dec Nov Dec Aug Sep Aug Sep Apr Oct Apr Oct Mar Mar Feb Feb Jul Jul May May 0% Jan Jun 0% Jan Jun ------15 15 ------15 15 15 15 - - 15 15 15 15 15 15 15 15 15 15 15 15 15 15 15 15 15 15 1-Month Period for Mid Severn/ Teme 1-Month Period for Avon to Evesham

250% 250%

200% 200%

150% 150%

100% 100%

50% 50% Nov Dec Nov Dec Aug Sep Aug Sep Apr Oct Apr Oct Mar Mar Feb Feb Jul Jul May May 0% Jan Jun 0% Jan Jun ------15 15 ------15 15 15 15 - - 15 15 15 15 15 15 15 15 15 15 15 15 15 15 15 15 15 15 1-Month Period for Lower Severn Estuary 1-Month Period for Upper Trent

250% 250%

200% 200%

150% 150%

100% 100%

50% 50% Nov Dec Nov Dec Aug Sep Aug Sep Apr Oct Apr Oct Mar Mar Feb Feb Jul Jul May May Jan 0% Jan Jun 0% Jun ------15 15 ------15 15 15 15 - - 15 15 15 15 15 15 15 15 15 15 15 15 15 15 15 15 15 15 1-Month Period for Tame 1-Month Period for Dove

250% 250%

200% 200%

150% 150%

100% 100%

50% 50% Nov Dec Nov Dec Aug Sep Aug Sep Apr Oct Apr Oct Mar Mar Feb Feb Jul Jul May May 0% Jan Jun 0% Jan Jun ------15 15 ------15 15 15 15 - - 15 15 15 15 15 15 15 15 15 15 15 15 15 15 15 15 15 15

Above average rainfall Below average rainfall 1-Month Period for Derwent (Midlands) 1-Month Period for Soar

250% 250%

200% 200%

150% 150%

100% 100%

50% 50% Nov Dec Nov Dec Aug Sep Aug Sep Oct Apr Apr Oct Mar Mar Feb Feb Jul Jul May May 0% Jan Jun 0% Jan Jun ------15 15 ------15 15 15 15 - - 15 15 15 15 15 15 15 15 15 15 15 15 15 15 15 15 15 15 1-Month Period for Lower Trent 1-Month Period for Lower Wye

250% 250%

200% 200%

150% 150%

100% 100%

250% 250%

200% 200%

150% 150%

100% 100%

250% 250%

200% 200%

150% 150%

100% 100%

50% 50% Nov Dec Aug Sep Apr Oct Mar Feb Apr Oct Jul May Feb Jul May Jan Jun Jan Jun Nov Dec 0% 0% Aug Sep Mar ------15 15 ------15 15 15 15 - - 15 15 15 15 15 15 15 15 15 15 15 15 15 15 15 15 15 15

Figure 3: Rainfall surplus / deficit charts for selected areas across the Midlands region of England (Source: NCIC Dataset NFFS).

Midlands Soil Moisture Deficit Map

Key: ___ Midlands Regional Boundary

Figure 4: Soil moisture deficits for weeks ending November 2015 (left panel) and December 2015 (right panel). Top row shows actual soil moisture deficits (mm) and bottom row 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, 2015). Crown copyright. All rights reserved. Environment Agency, 100026380, 2015.

Midlands Soil Moisture Deficit Charts

SMD Data Latest SMD Data Average SMD Data

Derwent Midlands - 116 Welsh Mountains 123 0 0

20 20

30 40

60 50

80 Soil moisture deficit (mm) Soil moisture deficit (mm) 70

80 100

120 100 Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Severn - 124 Upper Trent - 125 0 0

20 20

40 40

60 60

80 80 Soil moisture deficit (mm) Soil moisture deficit (mm)

100 100

120 120 Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Soar - 126 0

80 Soil moisture deficit (mm)

100

120 Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec

Figure 5: Soil moisture deficit charts for selected areas across the Midlands region of England (Source: MORECS Dataset NFFS).

Midlands Mean River Flow For December 2015

Midlands River Flow Charts

Exceptionally high Notably high Above normal Normal Below normal Notably low Exceptionally low ─── Latest data AUCKLEY, TORNE BEWDLEY US, SEVERN Ranking derived from data for the period Jun-1971 to Dec-2012 Ranking derived from data for the period Apr-1921 to Dec-2012

3 200 3

2 150

2 100

1 Flow (cumecs) (cumecs) Flow (cumecs) Flow 50 1

0 0 Mar-15 May-15 Jul-15 Sep-15 Nov-15 Jan-16 Mar-15 May-15 Jul-15 Sep-15 Nov-15 Jan-16

BUTTS BRIDGE, LUGG DERBY ST.MARYS US, DERWENT (MI) Ranking derived from data for the period Mar-1969 to Dec-2012 Ranking derived from data for the period Oct-1935 to Dec-2012

20 50

40 15

30 10 20 Flow (cumecs) (cumecs) Flow (cumecs) Flow 5 10

0 0 Mar-15 May-15 Jul-15 Sep-15 Nov-15 Jan-16 Mar-15 May-15 Jul-15 Sep-15 Nov-15 Jan-16

EBLEY MILL, FROME (GLOS) EVESHAM, AVON (MI) Ranking derived from data for the period Apr-1969 to Dec-2012 Ranking derived from data for the period Jan-1970 to Dec-2012

8 90 7 80 6 70

5 60 50 4 40 3 30 Flow (cumecs) (cumecs) Flow 2 (cumecs) Flow 20 1 10 0 0 Mar-15 May-15 Jul-15 Sep-15 Nov-15 Jan-16 Mar-15 May-15 Jul-15 Sep-15 Nov-15 Jan-16

Exceptionally high Notably high Above normal Normal Below normal Notably low Exceptionally low ─── Latest data HAW BRIDGE, SEVERN KEGWORTH US, SOAR Ranking derived from data for the period Jul-1971 to Dec-2012 Ranking derived from data for the period Mar-1991 to Dec-2012

40 350 35 300 30 250 25 200 20

150 15 Flow (cumecs) (cumecs) Flow (cumecs) Flow 100 10

50 5

0 0 Mar-15 May-15 Jul-15 Sep-15 Nov-15 Jan-16 Mar-15 May-15 Jul-15 Sep-15 Nov-15 Jan-16

LLANYBLODWEL, TANAT MARSTON ON DOVE, DOVE (MI) Ranking derived from data for the period Jun-1973 to Dec-2012 Ranking derived from data for the period Jul-1965 to Dec-2012

40 25 35

20 30

25 15 20

10 15 Flow (cumecs) (cumecs) Flow (cumecs) Flow 10 5 5

0 0 Mar-15 May-15 Jul-15 Sep-15 Nov-15 Jan-16 Mar-15 May-15 Jul-15 Sep-15 Nov-15 Jan-16

NORTH MUSKHAM, TRENT REDBROOK, WYE (HEREFORDSHIRE) Ranking derived from data for the period Oct-1968 to Dec-2012 Ranking derived from data for the period Oct-1969 to Dec-2012

300

200 250

150 200

150 100 100 Flow (cumecs) (cumecs) Flow (cumecs) Flow 50 50

0 0 Mar-15 May-15 Jul-15 Sep-15 Nov-15 Jan-16 Mar-15 May-15 Jul-15 Sep-15 Nov-15 Jan-16

STARETON, AVON (MI) TENBURY, TEME Ranking derived from data for the period Oct-1962 to Dec-2012 Ranking derived from data for the period Oct-1956 to Dec-2012

9 8 50 7 40 6

5 30 4 20 3 Flow (cumecs) (cumecs) Flow (cumecs) Flow 2 10 1 0 0 Mar-15 May-15 Jul-15 Sep-15 Nov-15 Jan-16 Mar-15 May-15 Jul-15 Sep-15 Nov-15 Jan-16

Exceptionally high Notably high Above normal Normal Below normal Notably low Exceptionally low ─── Latest data WALCOT, TERN WEDDERBURN BRIDGE, LEADON Ranking derived from data for the period Oct-1960 to Dec-2012 Ranking derived from data for the period Jul-1961 to Dec-2012

20 8 7

15 6 5

10 4 3 Flow (cumecs) (cumecs) Flow (cumecs) Flow 5 2 1 0 0 Mar-15 May-15 Jul-15 Sep-15 Nov-15 Jan-16 Mar-15 May-15 Jul-15 Sep-15 Nov-15 Jan-16

WORKSOP, RYTON YOXALL, TRENT Ranking derived from data for the period Jun-1970 to Dec-2012 Ranking derived from data for the period Oct-1959 to Dec-2012

2 40

2 35 2 30 1 1 25 1 20

1 15 Flow (cumecs) (cumecs) Flow Flow (cumecs) (cumecs) Flow 1 10 0 0 5 0 0 Mar-15 May-15 Jul-15 Sep-15 Nov-15 Jan-16 Mar-15 May-15 Jul-15 Sep-15 Nov-15 Jan-16

Figure 7: Monthly mean river flows for the past 10 months at selected gauging stations (Source: Environment Agency)

*Please note: In order to make use of historic river flow data at each site; long term averages are based non standardised periods of record. As a result sites will not be comparable.

Monthly Groundwater Levels For December 2015

Figure 8: Groundwater levels at the end of December 2015, classed relative to an analysis of historic December groundwater levels. © Crown Copyright. All rights reserved. Environment Agency, 100026380, 2015.

Midlands Groundwater Charts

Exceptionally high Notably high Above normal Normal Below normal Notably low Exceptionally low ─── Latest data ANTHONYS CROSS CROSSLEY HILL Ranking derived from data for the period Jan-1973 to Dec-2012 Ranking derived from data for the period Dec-1969 to Dec-2012

50 28

49 28

48 27

47 27

46 26

45 26 Level (mAOD) Level (mAOD) Level 44 25

43 25

42 24 Mar-13 Jul-13 Nov-13 Mar-14 Jul-14 Nov-14 Mar-15 Jul-15 Nov-15 Mar-13 Jul-13 Nov-13 Mar-14 Jul-14 Nov-14 Mar-15 Jul-15 Nov-15

FOUR CROSSES HEATHLANES - 23 Ranking derived from data for the period Jul-1969 to Dec-2012 Ranking derived from data for the period Jul-1971 to Dec-2012

116 64

115 63

114 62

114 62 Level (mAOD) Level (mAOD) Level 113 61

113 61

112 60 Mar-13 Jul-13 Nov-13 Mar-14 Jul-14 Nov-14 Mar-15 Jul-15 Nov-15 Mar-13 Jul-13 Nov-13 Mar-14 Jul-14 Nov-14 Mar-15 Jul-15 Nov-15

HODHILL FARM RAM HALL Ranking derived from data for the period Feb-1972 to Dec-2012 Ranking derived from data for the period Sep-1973 to Dec-2012

107 108

106 107 105 106 104 105 103 104 Level (mAOD) Level 102 (mAOD) Level

101 103

100 102 Mar-13 Jul-13 Nov-13 Mar-14 Jul-14 Nov-14 Mar-15 Jul-15 Nov-15 Mar-13 Jul-13 Nov-13 Mar-14 Jul-14 Nov-14 Mar-15 Jul-15 Nov-15

Exceptionally high Notably high Above normal Normal Below normal Notably low Exceptionally low ─── Latest data RIDER POINT VIA GELLIA WATCH HILL Ranking derived from data for the period Jan-1976 to Dec-2012 Ranking derived from data for the period Oct-1969 to Dec-2012

178 72

173 71 168 70 163 69 158 68 Level (mAOD) Level 153 (mAOD) Level

148 67

143 66 Mar-13 Jul-13 Nov-13 Mar-14 Jul-14 Nov-14 Mar-15 Jul-15 Nov-15 Mar-13 Jul-13 Nov-13 Mar-14 Jul-14 Nov-14 Mar-15 Jul-15 Nov-15

Figure 9: End Month Groundwater Levels over a 34 month time series at selected observation boreholes (Source: Environment Agency).

*Please note: In order to make use of historic groundwater data at each site; long term averages are based on non standardised periods of record. As a result sites will not be comparable.

Midlands Major Reservoirs

Please Note: Lake Vyrnwy, Llyn Clywedog and Elan Valley Reservoirs are located within Natural Resources Wales (NRW). However, as they are important to Midlands’ water resources they remain within the Midlands Water Situation Report.

Midlands Reservoir Stocks Current Reservoir Storage Reservoir Average Reservoir Storage Reservoir

Clywedog Vyrnwy

100.00 100

90.00 90

80.00 80

70.00 70 capacity 60.00 60

50.00 50

40 40.00 Percentage of live of Percentage live capacity Percentage of live live of Percentage 30 30.00

20 20.00

10 10.00

0 0.00 Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Draycote Derwent Reservoirs

100 100

90 90

80 80

70 70

60 60

50 50

40 40 Percentage of live of Percentage live capacity of Percentage live capacity 30 30

20 20

10 10

0 0 Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Carsington and Ogston Tittesworth Reservoir

100 100

90 90

80 80

70 70

60 60

50 50

40 40 Percentage of live of Percentage live capacity of Percentage live capacity 30 30

20 20

10 10

0 0 Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec

Current Reservoir Storage Reservoir Average Reservoir Storage Reservoir

Blithfield Reservoir Dove Reservoir

100 100

90 90

80 80

70 70

60 60

50 50

40 40 Percentage of live of Percentage live capacity Percentage of live of Percentage live capacity 30 30

20 20

10 10

0 0 Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Charnwood Reservoir Elan Reservoir

100 100

90 90

80 80

70 70

60 60

50 50

40 40 Percentage of live of Percentage live capacity of Percentage live capacity 30 30

20 20

10 10

0 0 Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec

Figure 11: 30 month reservoir stocks (Source: Severn Trent Water Plc. & South Staffordshire Water Plc).

*Please note: Long term averages are based non standardised periods of record.

Glossary

Rainfall Classification Method Explained

Previously, rainfall totals for the preceding month were reported as a percentage of the long term average (1961-90). The rainfall maps showed each hydrological area coloured according to a classification based on percentage of the LTA.

The new water situation report shows monthly (and cumulative monthly) rainfall totals in two ways; both as a percentage of the 1961-90 LTA (depicted as a value on the map) and classified according to the Cunnane bands (exceptionally low etc.) which provide the colours for the maps. The percentage of LTA and the Cunnane band are calculated for each hydrological area, and each time period independently and therefore direct comparisons between these two reporting methods cannot be made between months, cumulative time periods or across hydrological areas.

Using the Cunnane method provides a better illustration of whether the current or cumulative months rainfall totals can be considered to be normal etc. based on historic totals for given months, and using the full period of record for comparison. It also brings the reporting of rainfall status in line with river flows, using the same method as used for monthly mean river flows.

The Cunnane classes are defined by ranking historic monthly (or cumulative monthly) totals, using the full period of record. The ranked data are then used to define the category boundary values, according to the probabilities shown below. For example there is a 44% probability that rainfall will be defined as ‘normal’, yet only a 5% probability that rainfall will be either exceptionally high or exceptionally low.

Term Definition

Aquifer A geological formation able to store and transmit water.

Areal average rainfall The estimated average depth of rainfall over a defined area. Expressed in depth of water (mm).

Artesian The condition where the groundwater level is above ground surface but is prevented from rising to this level by an overlying continuous low permeability layer, such as clay.

Artesian borehole Borehole where the level of groundwater is above the top of the borehole and groundwater flows out of the borehole when unsealed.

Cumecs Cubic metres per second (m3s-1)

Effective rainfall The rainfall available to percolate into the soil or produce river flow. Expressed in depth of water (mm).

Flood Alert/Flood Warning Three levels of warnings may be issued by the Environment Agency. Flood Alerts indicate flooding is possible. Flood Warnings indicate flooding is expected. Severe Flood Warnings indicate severe flooding.

Groundwater The water found in an aquifer.

Long term average (LTA) The arithmetic mean calculated from the historic record, usually based on the period 1961-1990. However, the period used may vary by parameter being reported on (see figure captions for details). mAOD Metres Above Ordnance Datum (mean sea level at Newlyn Cornwall).

MORECS Met Office Rainfall and Evaporation Calculation System. Met Office service providing real time calculation of evapotranspiration, soil moisture deficit and effective rainfall on a 40 x 40 km grid.

Naturalised flow River flow with the impacts of artificial influences removed. Artificial influences may include abstractions, discharges, transfers, augmentation and impoundments.

NCIC National Climate Information Centre. NCIC area monthly rainfall totals are derived using the Met Office 5 km gridded dataset, which uses rain gauge observations.

Recharge The process of increasing the water stored in the saturated zone of an aquifer. Expressed in depth of water (mm).

Reservoir gross capacity The total capacity of a reservoir.

Reservoir live capacity The capacity of the reservoir that is normally usable for storage to meet established reservoir operating requirements. This excludes any capacity not available for use (e.g. storage held back for emergency services, operating agreements or physical restrictions). May also be referred to as ‘net’ or ‘deployable’ capacity.

Soil moisture deficit (SMD) The difference between the amount of water actually in the soil and the amount of water the soil can hold. Expressed in depth of water (mm).