The UK Water Resources Portal

The UK Water Resources Portal is an interactive tool to monitor the UK hydrological situation in (near) real-time at a range of spatial scales.

The portal brings together rainfall, river flow, soil moisture and groundwater data in one place, and showcases the use of live river flow data from the Environment Agency and COSMOS-UK soil moisture data.

Data are available in their raw format (e.g. millimetres for rainfall, metres cubed per second for river flows etc.) and standardised indices. The table below summarises what data are available. Note that standardised indices are not available for the COSMOS-UK soil moisture data due to the short data record lengths (the earliest records start in 2014).

Important notes

River flows:

  • Daily river flow data are available in England on a real-time basis using the Environment Agency's live data API for over 800 gauging stations. This means that daily flows are available in real-time.
  • Daily river flows received each month through the National Hydrological Monitoring Programme are also available in the UK Water Resources Portal, these include an extra 64 gauging stations across the UK.
  • Daily river flow data are shown as a solid black line for checked data and a dashed line for unchecked data, please note that unchecked data may be erroneous, but all data should be assumed to be provisional, and should not be directly used for decision-making.


  • The areal estimates of rainfall are based on a relatively sparse network and may yield different areal averages to results from higher density networks used by regulators/measuring agencies.

Soil moisture:

  • An equivalent standardised index for soil moisture is not included here. Since the COSMOS-UK records start from 2014 onwards, they are not yet long enough to compute a standardised index.


  • You can view up to four graphs at a time — if you change the data type, time scale or standardised index accumulation period, the graphs will also update if the data are available (if data aren't available the graph will blank).
  • Not all graph types are available for all data types — if you select a graph type and data type which aren't available for a particular site an error message will appear explaining this.

Data available in the UK Water Resources Portal

Variable Raw data — daily & monthly (unit) Standardised indices (name of index)
Rainfall — 5km grid    
(Standardised Precipitation Index, SPI)
Rainfall — catchments  
(Standardised Precipitation Index, SPI)
Rainfall — river basins    
(Standardised Precipitation Index, SPI)
River flows  
(Standardised Streamflow Index, SSI)
Soil moisture  
(volumetric water content %)
Groundwater levels  
(m above ordnance datum, maod)
(Standardised Groundwater Index, SGI)

Standardised Indices

The standardised indices have been added to the portal as they are commonly used to monitor droughts around the world — in fact the World Meteorological Organization recommend the use of the Standardised Precipitation Index for monitoring meteorological droughts.

In the UK Water Resources Portal we show standardised indices for rainfall (Standardised Precipitation Index), river flows (Standardised Streamflow Index) and groundwater (Standardised Groundwater Index) — see the table above.

The standardised indices show, for a given location and month, how much the variable (i.e. rainfall, river flows or groundwater) deviate from the long-term average. This means the indices can be compared between localities with very different rainfall regimes (comparing, say, a wet catchment in upland Scotland with a dry catchment in low-lying East Anglia), and between times of year.

The indices do not have a unit (i.e. they are dimensionless) with negative values indicating that rainfall, flows or levels are lower than average, whilst positive values show that conditions are above average. Extreme conditions are indicated by values greater than 2 (extremely wet) or less than -2 (extremely dry). The more extreme the values the more severe the conditions, but also less likely they are to occur.

Another benefit of these indices is that you can calculate them for different accumulation periods, so you can look at the deficits (or excesses) in rainfall or river flows over 1, 3 or 12 months etc. depending on your interest. Due to the slow response, or memory, in groundwater data for SGI only one accumulation period is shown for each site.

The standardised indices are sensitive to aspects of its formulation, for example the choice of statistical distribution or the standard period used to average the data. As such the results could vary when compared with other applications of the SPI, SSI or SGI. For more information on testing appropriate distributions for UK rainfall and river flow data, see Svensson et al. 2017. Note that a statistical distribution is not used in the derivation of the SGI (see Bloomfield and Marchant, 2013 for more information).

More information on each of the standardised indices is provided below.

Additional basemap layers

Two basemap layers are provided in addition to satellite or street maps:

More information on the standardised indices

Standardised Precipitation Index (SPI)

The SPI is calculated initially on a 5km grid, based on rainfall data from the UK Met Office. The 5km rainfall is aggregated up catchments and to river basins from UKCEH’s Integrated Hydrological Units (IHU) dataset at the group scale showing 405 whole river catchments of around 400km2 across the UK. The Standardised Precipitation Index is calculated using the Gamma distribution and a standard period of 1961–2010. For more information on the SPI see McKee et al. 1993, and the references below for more information on the UK SPI datasets.

Standardised Streamflow Index (SSI)

The SSI is calculated using average monthly river flows for each catchment using the Tweedie distribution and standard period of 1961–2010. For more information on the SSI see Vicente-Serrano et al. 2011, and its application in the UK see Barker et al. 2016.

Standardised Groundwater Index (SGI)

The SGI is calculated by standardising over the period of record available at each borehole. For more information on the SGI see Bloomfield & Marchant, 2013.

More information about the UK Water Resources Portal

For more information on major flood and drought events see the occasional reports of the National Hydrological Monitoring Programme.

If you would like to submit feedback about the UK Water Resources Portal, please send it to

We plan to add the following datasets/types to the UK Water Resources Portal in the future:

  • Further rainfall datasets (e.g. gridded and gauged rainfall)
  • Satellite data such as the Vegetation Condition Index
  • Gridded soil moisture (either modelled or from satellites)

The UK Water Resources Portal is a development of the UK Drought Portal which has been updated each month since June 2017. The UK Drought Portal however, showed only a commonly used drought index — the Standardised Precipitation Index. Within ENDOWS we worked with South West Water and the Environment Agency in Devon and Cornwall to develop a prototype portal for the south west of England to work out how these different datasets can be brought together and how data can be presented to work alongside existing monitoring tools such as Environment Agency Water Situation Reports.

We know a number of users are still using the UK Drought Portal so the UK Water Resources Portal will run in parallel with the UK Drought Portal. We hope that the UK Water Resources Portal will replace the UK Drought Portal in the (near) future.


The UK Water Resources Portal was primarily developed in the ENDOWS project (Engaging diverse stakeholders and publics with outputs from the UK Drought and Water Scarcity Programme), funded by the Natural Environment Research Council award number NE/L01016X/1. Additional funding was provided by the Natural Environment Research Council award number NE/R016429/1 as part of the UK-SCAPE programme delivering National Capability.

NRFA river flow and BGS groundwater level data provided by the Environment Agency (for England), Natural Resources Wales, the Scottish Environmental Protection Agency and Department of Infrastructure - Rivers in Northern Ireland.


Barker, L J, Hannaford, J, Chiverton, A, and Svensson, C. From meteorological to hydrological drought using standardised indicators, Hydrology and Earth System Sciences, 20, 2483–2505, 2016.

Bloomfield, J P and Marchant, B P. Analysis of groundwater drought building on the standardised precipitation index approach, Hydrol. Earth Syst. Sci., 17, 4769–4787, 2013.

McKee, T B, Doesken, N J, and Leist, J. The relationship of drought frequency and duration time scales, 8th Conference on Applied Climatology, 17–22 January 1993, Anaheim, California, 179–184, 1993.

Svensson, C, Hannaford, J, and Prosdocimi, I. Statistical distributions for monthly aggregations of precipitation and streamflow in drought indicator applications, Water Resources Research, 53, 999–1018, 2017.

Vicente-Serrano, S M, López-Moreno, J I, Beguería, S, Lorenzo-Lacruz, J, Azorin-Molina, C, and Morán-Tejeda, E. Accurate computation of a streamflow drought index, Journal of Hydrologic Engineering, 17, 318–332, 2011.

SPI Datasets

Tanguy, M, Fry, M, Svensson, C, Hannaford, J. 2017. Historic Gridded Standardised Precipitation Index for the United Kingdom 1862-2015 (generated using gamma distribution with standard period 1961–2010) v4. NERC Environmental Information Data Centre.

Tanguy, M, Fry, M, Svensson, C, Hannaford, J. 2017. Historic Standardised Precipitation Index time series for IHU Hydrometric Areas (1862–2015) v2. NERC Environmental Information Data Centre.

Tanguy, M, Fry, M, Svensson, C, Hannaford, J. 2017. Historic Standardised Precipitation Index time series for IHU Groups (1862–2015) v2. NERC Environmental Information Data Centre.