Hydrological Summary for the General July bore all of the hallmarks of a typical British summer: sunny and occasionally very hot weather accompanied by disruptive thunderstorm activity. Most memorably, a short exceptionally hot spell in late July, driven by a strong plume of continental air, culminated on the 25th in a new record UK temperature (for any month) of 38.7°C at Cambridge Botanic Gardens. However, this was bookended by intense thunderstorms and heavy rainfall which triggered disruptive surface water and fluvial flooding, and had severe impacts in northern Britain. July rainfall totals were notably above average for the UK, particularly across most of northern and central Britain, but were generally below average further south and west. Soil moisture deficits (SMDs) were near-zero across north-west Britain but drier than average in south-east . River flows were above average in north-west Scotland, the Midlands and catchments draining the southern Pennines. In contrast, river flows in southern England and south Wales were generally below normal. Groundwater levels receded as normal for the month, and levels in the Chalk of eastern England remained notably to exceptionally low. Reservoir stocks for England & Wales were near-average for the time of year (only Roadford and Colliford were substantially below average), and for Scotland and particularly Northern Ireland were above average. Excessive summer rainfall and generally healthy reservoir stocks have alleviated water resource pressure in 2019. However, as expected, near-average summer rainfall across the Chalk aquifer of south-east England has not remedied the current notably and exceptionally low groundwater levels. As such, the water resources situation for 2020 in these areas will be influenced by the onset and magnitude of recharge over the winter half-year 2019/2020. Rainfall The first half of July was dominated by anticyclonic there were swift increases in flows across northern conditions with plenty of dry summer weather; rainfall Britain. On the 22nd, the Carron recorded its highest July was generally restricted to brief interludes (e.g. 80mm daily mean flow in a series from 1979, more than 150% at Fettercairn, Kincardineshire on the 10th), albeit of the previous maximum. River flooding on the 28th in triggering surface water flooding and impacting power localised parts of northern England was reported. The and transport networks on 11th/12th (e.g. in Manchester). Mersey recorded its two highest July daily mean flows on From mid‑month, more unsettled weather followed under record (in a series from 1976) on the 28th and 31st. Rivers a south-westerly airflow, bringing further disruption to across the southern Pennines also responded markedly to power and transport infrastructure from convective activity: exceptional rainfall on the 30th, destroying an iconic bridge on the 19th, in Aberdeen, Cheshire and south Wales; near Grinton (North ). July mean flows were on the 24th/25th, affecting up to 20,000 properties in generally above normal in northern Scotland, Yorkshire northern Britain; and on the 28th (e.g. 91mm at Rochdale and the East Midlands, and were particularly notable in in 24 hours to 9pm on the 28th), causing surface water parts of north-west England (more than twice the average flooding of properties and transport networks in Scotland on the Mersey). Further south, July mean flows were and north‑west England. Most significantly of all, on the below normal, notably so in parts of East Anglia, Dorset 30th, persistent convective activity across the Peak District and south Wales. Flows on the Brue, Taw and Tawe were and Yorkshire Dales resulted in remarkable rainfall totals: around a third of average, and the Tywi registered less than 95mm at Old Spital Farm (58mm in 45 minutes) and a quarter of average. Average river flows for the summer 102mm at Arkle Town (82mm in 90 minutes). This caused so far (June-July) have been above average across Wales, severe disruption through surface water flooding of local northern and eastern Scotland, and central and north-east road networks and landslides across railway lines in the England, with exceptionally high flows on the Wharfe, Lud Yorkshire Dales. Substantially above average July rainfall and Weaver. The latter recorded three times its average totals were recorded in northern England, the Midlands flow and registered as the second highest June-July mean and much of Scotland, most notably in an area stretching flow (behind 2007) in a series from 1938. through the southern Pennines, Cheshire (which recorded July 2019 more than twice the July average) and the Midlands. Groundwater Conversely, rainfall was generally below average in Wales SMDs were drier than average across most of the Chalk (61% of average) and southern England, and notably low aquifer of south-east England. Levels fell at all of the in south-west Wales and parts of Wessex and Norfolk. Chalk boreholes (apart from Aylesby where a rise was Rainfall accumulations for the summer so far (June-July) recorded). Levels were generally below normal or were above average for the vast majority of the country, notably low, especially so in eastern England where 137% of average for the UK. Large swathes of Cheshire, Dial Farm remained exceptionally low. July levels at Lincolnshire and the Midlands received more than 170% Frying Pan Lodge, Dial Farm and Washpit Farm were their of average (already more than their entire summer average lowest since 1997. Nevertheless, Killyglen and two Chalk rainfall), in addition to parts of Northumberland and boreholes in south‑east England ended July in the normal Kent. Only parts of south Wales and south-west England range. Levels at both of the Jurassic limestone boreholes registered below average rainfall. in central England fell but remained above average. Levels in the Magnesian limestones fell and remained below River flows average. In the Carboniferous Limestone levels fell, to River flows generally began July near or below average and notably low in south Wales but remained in the normal were initially in recession through the first fortnight. One range at Alstonfield. In the Permo-Triassic sandstones, exception to this was on the 11th, when the Naver exceeded levels generally fell and remained in the normal range or its previous July peak flow record by around 10% (in a below (except at Newbridge), reflecting the variations in series from 1977). In East Anglia, the Waveney established both July rainfall and SMDs. Levels fell at Lime Kiln Way new daily flow minima for five days mid-month, and the (Upper Greensand) and were below normal. Levels at continued lack of rainfall in southern Britain led to some Royalty Observatory in the Fell Sandstone receded but sustained low flows throughout July. From mid‑month, remained in the normal range. Rainfall . . . Rainfall . . . Rainfall accumulations and return period estimates Percentages are from the 1981-2010 average.

Jul Region Rainfall Jun 19 – Jul 19 Feb 19 – Jul 19 Nov 19 – Jul 19 Aug 18 – Jul 19 2019 RP RP RP RP United mm 89 200 522 828 1122 Kingdom % 118 137 8-12 112 5-10 101 2-5 99 2-5 England mm 68 178 397 624 819 % 111 145 8-12 110 2-5 101 2-5 97 2-5 Scotland mm 133 235 688 1083 1528 % 141 133 8-12 113 10-15 98 2-5 101 2-5 Wales mm 55 214 647 1107 1489 % 61 123 2-5 115 5-10 107 2-5 105 2-5 Northern mm 87 199 571 878 1107 Ireland % 106 126 5-10 118 10-15 106 2-5 97 2-5 England & mm 66 183 431 690 912 Wales % 101 141 5-10 111 2-5 102 2-5 99 2-5

North West mm 137 259 639 954 1303 % 158 156 10-20 129 25-40 108 2-5 106 2-5 Northumbria mm 94 207 471 643 877 % 140 156 10-20 124 10-15 101 2-5 101 2-5 Severn-Trent mm 76 214 424 611 788 % 127 174 20-30 122 5-10 107 2-5 101 2-5 Yorkshire mm 86 189 416 622 804 % 141 147 8-12 113 2-5 101 2-5 96 2-5 Anglian mm 47 152 289 427 571 % 90 142 8-12 102 2-5 95 2-5 92 2-5 Thames mm 43 138 303 495 650 % 84 135 2-5 98 2-5 95 2-5 91 2-5 Southern mm 43 135 316 583 752 % 86 136 2-5 99 2-5 101 2-5 94 2-5 Wessex mm 36 130 354 647 821 % 63 114 2-5 97 2-5 100 2-5 93 2-5 South West mm 51 158 463 915 1169 % 65 106 2-5 93 2-5 100 2-5 95 2-5 Welsh mm 55 211 626 1066 1433 % 63 126 2-5 115 5-10 107 2-5 105 2-5 Highland mm 132 244 778 1218 1809 % 131 127 5-10 109 5-10 92 2-5 100 2-5 North East mm 102 190 529 791 1045 % 140 133 2-5 123 10-15 108 2-5 103 2-5 Tay mm 115 210 616 971 1309 % 139 132 5-10 114 5-10 99 2-5 98 2-5 Forth mm 118 214 567 842 1121 % 145 135 8-12 114 8-12 96 2-5 93 2-5 Tweed mm 109 207 542 761 1040 % 141 140 8-12 125 10-20 102 2-5 101 2-5 Solway mm 140 231 723 1187 1592 % 143 126 5-10 122 25-40 111 8-12 107 5-10 Clyde mm 182 296 793 1287 1803 % 158 140 15-25 111 5-10 98 2-5 99 2-5 % = percentage of 1981-2010 average RP = Return period Important note: Figures in the above table may be quoted provided their source is acknowledged (see page 12). Where appropriate, specific mention must be made of the uncertainties associated with the return period estimates. The RP estimates are based on data provided by the Met Office and reflect climatic variability since 1910; they also assume a stable climate. The quoted RPs relate to the specific timespans only; for the same timespans, but beginning in any month the RPs would be substantially shorter. The timespans featured do not purport to represent the critical periods for any particular water resource management zone. For hydrological or water resources assessments of drought severity, river flows and/or groundwater levels normally provide a better guide than return periods based on regional rainfall totals. Note that precipitation totals in winter months may be underestimated due to snowfall undercatch. All monthly rainfall totals since January 2018 are provisional. 2 Rainfall . . . Rainfall . . . July 2019 rainfall June 2019 - July 2019 rainfall as % of 1981-2010 average as % of 1981-2010 average

170 170 150 150 130 130 110 110 90 90

70 70

% of average of % % of average of % 50 50 30 30

MORECS Soil Moisture Deficits* July 2019

The Hydrological Outlook provides an insight into future hydrological conditions across the UK. Specifically it describes likely trajectories for river flows and groundwater levels on a monthly basis, with particular focus on the next SMD (mm) three months. 0 - 10 10 - 30 The complete version of the Hydrological Outlook UK can 30 - 50 50 - 70 be found at: www.hydoutuk.net/latest-outlook/ 70 - 90 90 - 110 110 - 130 Period: from August 2019 Over 130 Issued: 08.08.2019 * For a grass cover using data to the end of July 2019

The outlook is for a continuation of below normal river flows across southern England and East Anglia throughout August. Over the next three months, flows in this area are likely to be normal to below normal. Conversely, in central England, flows in the majority of catchments are likely to be above normal for August, and normal to above normal over the three month period August-October. Elsewhere across the northern and western parts of the UK, flows are expected to be within the normal range. Groundwater levels across the southern and eastern Chalk aquifer are likely to be below normal for August. Elsewhere, groundwater levels are most likely to be within the normal range for August.

©© NERCNERC 20 1(CEH)8. © Crow n2019 copyrigh t©. Crown copyright. 3 River flow . . . River flow . . .

Naver (!170 June 2019 - Inver (!136 (!121 Helmsdale July 2019 Ewe (!147 (!151 Oykel Spey Deveron !136 151 (!159 (!139 ( (! 137 Ythan Carron Ness (! (!131 Dee (!152 Nevis Tay (!142 Luss (!130 Earn (!86 Tyne (!117 (!79 (!166 Tweed Clyde

Naver (!117 Coquet (!119 Cree (!88 Nith 197 Mourne Bush Eden Tyne (! 115 111 (!153 (! 119 (! Inver (! Tees (!143 Derwent (!124 !111 (!163 (Helmsdale (!105 189 Ewe (! Leven 114 Annacloy (! 149 Spey Deveron 112 Wharfe (! Oykel Lune(! (!77 187 (! Derwent (!134 Ribble 113 (!115 (!111 Aire (! 173 141 Mersey (! ! Don ( 119 136 Ythan Conwy (! (! (!169 178 Lud Carron Ness Derwent (! 302 (!124 Erch !146 (! 95 Dee ( 180 (! (!111 Weaver (!138(! (!135 Dee (!130 Witham (!141 Dove Trent Nevis (!150 Soar (!60 Tay Severn Stringside (!51 128 (!224 (! Teifi Great Little (!79 Ouse Luss 130 (!142 (!145 Avon Ouse (! 128 (!Yscir Colne 67 Earn Tywi (!72 Coln (! 82 (!132 69 66 (! Tyne 81 (! (!Lee (! (!71 Wye Thames 60 Tawe ! Lambourn 74 87 ( 117 (! 63 Tweed Cynon (!(! Great (! (!76 Brue Avon (!106 (!84 64 Blackwater Stour Taw 60 (! Medway Clyde 92 (! (!76 (! (!93 Itchen (!99 123 Tone Warleggan (! (!62 Ouse (!70 Coquet 116 67 Exe Stour ! 61 (! 67 ( Cree 79 (! (! (!Nith Kenwyn Dart Mourne Bush Eden Tyne (!88 Tamar 111 114 (! 100 !78 © NERC 2019. © Crown copyright. (! (! ( © NERC (CEH) 2019 © Crown copyright. Tees Derwent (!91 156 (!51 (! Annacloy Leven (!101 74 Wharfe Lune(! (!58 149 July 2019 (! Derwent 103 Ribble (! Aire(!117 Mersey Don 113 Conwy (! (!229 147 Lud Derwent (! Key 177 (!132 Erch (!95 (! 117 (!68 Weaver (!102(! % of long-term average (!59 Dee (!123 Witham 25 Dove Trent (record figure when circled) (!155 Soar (!57 Severn Stringside 43 (!73 (! Exceptionally high flow Teifi Great Little (!62 Ouse (!59 (!99 Avon Ouse (!44 Yscir Colne 54 Notably high flow Tywi(!24 Coln (! (!69 77 61 31 (! (!Lee (! (!46 Wye Thames Above normal Tawe Lambourn 73 82 (!75 Cynon (!(! Great Brue Avon (!97 (!73 Normal range 60 Blackwater Stour Taw 35 (! Medway 65 (! !35 (! 87 Itchen 88 ( (! (! Below normal 53 Tone Warleggan (! (!51 Ouse 47 Exe Stour Notably low flow (!51 (!(!47 Kenwyn Dart 74 (! Tamar Exceptionally low flow ©© NERC NERC 2(CEH)019. © 2019.Crown ©co pCrownyright. copyright. Based on ranking of the monthly flow* River flows *Comparisons based on percentage flows alone can be misleading. A given percentage flow can represent extreme drought conditions in permeable catchments where flow patterns are relatively stable but be well within the normal range in impermeable catchments where the natural variation in flows is much greater. Note: the averaging period on which these percentages are based is 1981-2010. Percentages may be omitted where flows are under review.

4 River flow . . . River flow . . .

River flow hydrographs *The river flow hydrographs show the daily mean flows (measured in3 m s-1) together with the maximum and minimum daily flows prior to August 2018 (shown by the shaded areas). Daily flows falling outside the maximum/minimum range are indicated where the bold trace enters the shaded areas. The dashed line represents the period-of-record average daily flow.

5 River flow . . . River flow . . .

6 Groundwater . . . Groundwater

Groundwater levels (measured in metres above ordnance datum) normally rise and fall with the seasons, reaching a peak in the spring following replenishment through the winter (when evaporation losses are low and soil moist). They decline through the summer and early autumn. This seasonal variation is much reduced when the aquifer is confined below overlying impermeable strata. The monthly mean and the highest and lowest levels recorded for each month are displayed in a similar style to the river flow hydrographs. Note that most groundwater levels are not measured continuously and, for some index wells, the greater frequency of contemporary measurements may, in itself, contribute to an increased range of variation. 7 Groundwater . . . Groundwater

Alstonfield

8 Groundwater . . . Groundwater

Key

Monthly rank/Period of record J1/25 (record figure when circled) (! Exceptionally high levels (! Notably high levels (! Above normal

(! Normal range (! Below normal (! Notably low levels (! Exceptionally low levels

Royalty 10/29 Observatory(! Aquifer

Chalk

Newbridge (!20/27 Jurassic limestones Killyglen (!16/35 Skirwith Aycliffe Permo-Triassic sandstones 20/40 (! (!12/43 Magnesian Limestone Carboniferous Limestone Wetwang (!6/48 Brick House Dalton Holme Farm (!8/38 (!16/131

(!8/40 Aylesby Alstonfield Llanfair D.C. New Red (!18/48 (!21/46 Lion Weir Farm (!47/56 (!11/35 Washpit (!8/70 Farm 9/44 Frying Pan (! (!4/47 Lodge Redlands Nuttalls Dial Farm Hall Farm!2/51 (!4/54 ( Ampney 13/132 Greenfield Garage Crucis (! Pant y Therfield Rectory (!3/26 Lladron 51/61 Stonor (! Park (!5/59 (!3/24 (!18/87 Tilshead Rockley 15/76 Chipstead 7/50 (! West (! 16/49 (! Little Woodyates Houndean Bucket Manor 20/73 Bussells (! 13/185 (!11/43 Farm No.7a (! 14/50 12/48 (! !29/78 Westdean No.3 (! Chilgrove ( 13/46 Lime (! House Kiln Ashton Way Farm ©© BGS NER NERCC 2019 2019.

Groundwater levels - July 2019 The calculation of ranking has been modified from that used in summaries published prior to October 2012. It is now based on a comparison between the most recent level and levels for the same date during previous years of record. Where appropriate, levels for earlier years may have been interpolated. The rankings are designed as a qualitative indicator, and ranks at extreme levels, and when levels are changing rapidly, need to be interpreted with caution.

9 Reservoirs . . . Reservoirs . . . Guide to the variation in overall Comparison between overall reservoir stocks for England and reservoir stocks for England and Wales Wales in recent years

Percentage live capacity of selected reservoirs at end of month

Capacity 2019 2019 2019 Jul Min Year* 2018 Diff Area Reservoir (Ml) May Jun Jul Anom. Jul of min Jul 19-18 North West N Command Zone • 124929 67 69 61 -2 23 1984 41 20 Vyrnwy 55146 97 100 91 15 45 1984 69 22 Northumbrian Teesdale • 87936 85 84 80 6 45 1989 61 20 Kielder (199175) 91 90 90 0 66 1989 77 13 Severn-Trent Clywedog 49936 100 99 96 11 50 1976 72 24 Derwent Valley • 46692 77 81 66 -7 43 1996 52 14 Yorkshire Washburn • 23373 84 95 81 8 50 1995 57 24 Bradford Supply • 40942 73 88 70 -1 38 1995 52 19 Anglian Grafham (55490) 90 93 86 -4 66 1997 83 2 Rutland (116580) 94 96 95 9 74 1995 89 6 Thames London • 202828 88 95 84 -3 73 1990 80 4 Farmoor • 13822 98 98 99 2 84 1990 98 0 Southern Bewl 31000 92 89 82 6 45 1990 84 -2 Ardingly 4685 95 94 79 -6 65 2005 80 -1 Wessex Clatworthy 5364 89 100 85 12 43 1992 59 26 Bristol • (38666) 90 86 78 3 53 1990 71 7 South West Colliford 28540 83 75 65 -13 47 1997 75 -10 Roadford 34500 73 70 59 -18 46 1996 70 -11 Wimbleball 21320 94 95 85 8 53 1992 73 13 Stithians 4967 93 89 77 7 39 1990 67 11 Welsh Celyn & Brenig • 131155 93 94 91 2 65 1989 71 20 Brianne 62140 90 98 89 -1 67 1995 71 18 Big Five • 69762 85 87 75 -2 41 1989 58 17 Elan Valley • 99106 93 97 85 3 53 1976 62 23

Scotland(E) Edinburgh/Mid-Lothian • 97223 88 85 81 -2 51 1998 81 0 East Lothian • 9317 100 100 100 10 72 1992 83 17 Scotland(W) Loch Katrine • 110326 88 91 87 12 53 2000 62 24 Daer 22494 85 83 81 0 56 2013 64 17 Loch Thom 10798 88 97 98 14 59 2000 83 15

Northern Total+ • 56800 93 93 87 9 54 1995 68 19 Ireland Silent Valley • 20634 96 96 87 13 42 2000 64 23

( ) figures in parentheses relate to gross storage • denotes reservoir groups *last occurrence + excludes Lough Neagh

Details of the individual reservoirs in each of the groupings listed above are available on request. The percentages given in the Average and Minimum storage columns relate to the 1988-2012 period except for West of Scotland and Northern Ireland where data commence in the mid-1990s. In some gravity-fed reservoirs (e.g. Clywedog) stocks are kept below capacity during the winter to provide scope for flood attenuation purposes. Monthly figures may be artificially low due to routine maintenance or turbidity effects in feeder rivers. © NERC (CEH) 2019. 10 Location map . . . Location map

Shetland Isles

# Naver Helmsdale Orkney # Inver Isles # # Oykel

E # w Western e Isles # on rr e Ca si on s # er # # # Lo ev D Yth Highland North East s an s Scotland e ey # N Sp Don# Tay #Dee Forth B e rv # Nevis ie # Clyde Tweed Northumbrian Ta#y Solway Northern Earn # Ireland " Katrine North For Luss # # th West Yorkshire East England Leven Lothian G West e # yn C Lothian T " Thom l # yd " Whiteadder e # #! Royalty Observatory

eed Midlands " Edinburgh/ Tw Nith Anglian Mid-Lothian C G oqu et # Welsh " Daer #Bush Braden # Kielder G Thames Faughan # Lower C ! Newbridge # re Bann #e # Tyne # ! # South Killyglen # E Wessex Mourne d South West e Southern n Tyne England C # amowen n # Skirwith ! Aycliffe ga# Derwent # ! La " " " # Northern Haweswater & es # Teesdale Te Annacloy Thirlmere D Command n o e v Zone v e Silent Valley e e # n # L Wharfe " u

L Bradford Supply # " Wetwang Washburn # ! " # O D

u e

r # s w le e ! b ! e Dalton ib Brick n # R House Farm # t Holme " Aire Pennines ! on# Aylesby Derwent D sey # Valley Mer " d

Lu#

t n

D e # r W

e T Celyn & Llanfair r # r i e w Dover th # v a Brenig ! ! e a m D.C. Alstonfield n Beck New Erch Conwy e " t # # # # W # Red Dee Lion # D # ! # Weir Farm ove G Vyrnwy ! ! We nsu fi # m y Washpit D r G # S ! a Rutland Farm eve o # Clywedog rn S # Stringside G Nuttalls ! Frying Pan # Lodge Farm Waveney Elan # Littl e Ou Brianne Valley Grafham G se " use Teme von t O ! Dial # A # rea G W G Farm Y ye Redlands Hall # s # ! c # i ! i r Therfield # w Gauging Station(River name) Teifi y # T Rectory # # U C Coln Greenfield s o e k l ! e " n Farmoor Groundwater index well Garage w # # a Big Ampney # " ! T Cy Stonor # no Five Crucis! Mimram Lee n # Park G Reservoir - individual ! Pant y La London Rockley m Pa Thames y Lladron bo n " wa u g # B ed ! r l M " ! n # a # Reservoir - group (general location only) Bristol # c # k " Kennet w a ! Chipstead # Wimbleball A t Great Clatworthy Tilshead e # Br ! v r M Chalk ue o t o # Stour ! n s l Little Bucket West # e e T Farm G # Woodyates Itchen G G Compton Ardingly G O Bewl Jurassic limestones # # Manor us ! # House #e T Tone # a S !! Chilgrove Houndean w Exe to ! Permo-Triassic sandstones ! Lime P ur # House Bottom # r id # Roadford ! te Kiln Way dl ! t e # W G Bussells O a Westdean # ! # L lli Magnesian Limestone y ng No.3 Colliford No.7A m to in n G # Ashton g # # to Carboniferous Limestone Tamar # Farm n Gannel Warleggan D a r Minor aquifers have been omitted # t G Kenwyn © NERC (CEH, BGS) 2019 © Crown copyright Stithians

© NERC (CEH, BGS) 2019. © Crown copyright.

11 NHMP

The National Hydrological Monitoring Programme Water; supplementary rain gauges are operated by the (NHMP) was started in 1988 and is undertaken jointly by Met Office. The Met Office NCIC monthly rainfall series the Centre for Ecology & Hydrology (CEH) and the British extend back to 1910 and form the official source of UK areal Geological Survey (BGS). The NHMP aims to provide an rainfall statistics which have been adopted by the NHMP. authoritative voice on hydrological conditions throughout The gridding technique used is described in Perry MC and the UK, to place them in a historical context and, over Hollis DM (2005) available at time, identify and interpret any emerging hydrological http://www.metoffice.gov.uk/climate/uk/about/methods trends. Hydrological analysis and interpretation within the Programme is based on the data holdings of the National Long-term averages are based on the period 1981-2010 and River Flow Archive (NRFA; maintained by CEH) and are derived from the monthly areal series. National Groundwater Level Archive (NGLA; maintained by BGS), including rainfall, river flows, borehole levels, The regional figures for the current month in the hydrological and reservoir stocks. summaries are based on a limited rain gauge network so these (and the associated return periods) should be regarded The Hydrological Summary is supported by the as a guide only. Natural Environment Research Council award number NE/R016429/1 as part of the UK-SCAPE programme The monthly rainfall figures are provided by the Met Office delivering National Capability. NCIC and are Crown Copyright and may not be passed on to, or published by, any unauthorised person or organisation.

Data Sources For further details on rainfall or MORECS data, please contact the Met Office: The NHMP depends on the active cooperation of many data Tel: 0870 900 0100 suppliers. This cooperation is gratefully acknowledged. Email: [email protected] River flow and groundwater level data are provided by the Environment Agency (EA), Natural Resources Wales - Cyfoeth Naturiol Cymru (NRW), the Scottish Environment Protection Agency (SEPA) and, for Northern Ireland, the Enquiries Department for Infrastructure - Rivers and the Northern Ireland Environment Agency. In all cases the data are Enquiries should be directed to the NHMP: subject to revision following validation (high flow and low flow data in particular may be subject to significant Tel: 01491 692599 revision). Email: [email protected]

Details of reservoir stocks are provided by the Water A full catalogue of past Hydrological Summaries can be Service Companies, the EA, Scottish Water and Northern accessed and downloaded at: Ireland Water. http://nrfa.ceh.ac.uk/monthly-hydrological-summary-uk The Hydrological Summary and other NHMP outputs may also refer to and/or map soil moisture data for the Some of the features displayed on the maps contained in UK. These data are provided by the Meteorological Office this report are based on the following data with permission Rainfall and Evaporation Calculation System (MORECS). of the controller of HMSO. MORECS provides estimates of monthly soil moisture deficit in the form of averages over 40 x 40 km grid squares i. Ordnance Survey data. © Crown copyright and/or over Great Britain and Northern Ireland. The monthly time database right 2005. Licence no. 100017897. series of data extends back to 1961. ii. Land and Property Services data. © Crown copyright and database right, S&LA 145. Rainfall data are provided by the Met Office. To allow iii. Met Office rainfall data. © Crown copyright. better spatial differentiation the rainfall data for Britain are presented for the regional divisions of the precursor All rights reserved. Unauthorised reproduction infringes organisations of the EA, NRW and SEPA. The areal crown copyright and may lead to prosecution or civil rainfall figures have been produced by the Met Office proceedings. National Climate Information Centre (NCIC), and are based on 5km resolution gridded data from rain gauges. Text and maps in this document are © NERC (CEH) 2019 The majority of the full rain gauge network across the UK unless otherwise stated and may not be reproduced without is operated by the EA, NRW, SEPA and Northern Ireland permission.

08/2019 12