River water quality

In England the Environment Agency are responsible for monitoring the quality of water in rivers, as well as bathing waters. Since 2009 standards of river water have been measured according to standards set in the The Water Framework Directive (WFD), which was adopted on 23 October 2000.

England is covered by 10 'River Basin Districts'. Lancashire mainly lies within the North West river basin district. A very small part near Earby in Pendle district including Kelbrook and Salterforth is in the Humber river basin district. Most water bodies in Lancashire eventually flow out into the Irish Sea through the estuaries of the Ribble, Wyre and Lune rivers. Some in the south of the county flow southwards and join up with tributaries of the Mersey. It is only those water bodies in the Humber river basin district that flow eastwards into Yorkshire that finally merge with the North Sea. This is not very surprising, as parts of the boundary between the two counties follow the ridges and hilltops that act as watersheds which also define the edges of the river catchments.

The River Basin Districts are divided into 'Management Catchments' which are further divided into 'Operational Catchments' each of which have a number of 'Water Bodies' which are assessed individually. The 'Water Body' may refer to a river, lake, reservoir, canal, aquifer, or inter-tidal part of an estuary. As such the areas covered may and do overlap. Where the 'Water Body' refers to a river, a number of separate streams may be included. It would appear that the assessment is area based, which allows total coverage of England.

The quality of river water is most important for aquatic life, such as fish. Unlike bathing water quality, which has direct health implications for humans, river water quality is less critical for most residents of Lancashire. Much of the drinking water used in the county is derived from the lakes and rivers monitored by the Environment Agency, and also from the groundwater aquifers, but this water is further treated at special plants. The quality of drinking water is also sampled and tested at the point of delivery, or straight from the tap.

The General Quality Assessment (GQA) was the Environment Agency's national indicator for water quality in rivers and canals, from 1990 until 2009. These assessments were made for Biological, Chemical and Nutrients and undertaken at sample points for discrete river stretches until 2007, when testing was reduced to a smaller set of headline rivers.

The Environment Agency is aiming to achieve good status in at least 60% of waters by 2021 and in as many waters as possible by 2027.

A very searching analysis of the Water Framework Directive explains some of the complexities of achieving the highest standards can be found in this Science Direct article. A water body would fail to reach the standard if it impacted on adjoining water bodies in some way such as exceeded normal abstraction rates. Unlike bathing beaches, the water bodies tend to be directly connected. 

The national picture (2016)

Key Findings from EA State of the Environment: Water Quality
In 2016, 86% of river water bodies had not reached good ecological status. The main reasons for this are agriculture and rural land management, the water industry, and urban and transport pressures.
Pollutant loads to rivers from water industry discharges have declined in recent years, with reductions of up to 70% since 1995.
Over the last decade the number of serious water pollution incidents from water companies has remained broadly the same, with about 60 incidents each year. That is more than one a week.

The situation in the Lancashire-14 area (2016)

In terms of overall water body quality, for the 150 rivers and transitional waters catchments, 32 were good, 99 were moderate, 13 were poor and 6 bad. Of the bad, 3 were transitional waters: the Kent, Ribble and Lune estuaries. The 3 bad rivers were the Darwen, from its confluence with the Roddlesworth to the tidal limit, Skirden Beck and Leighton Beck, which forms part of the northern boundary of the county.

The Mill Brook, Longton Brook and Douglas estuary appear as bad because they are covered by the Ribble estuary catchment, rather than being classified individually.

Of the 56 lakes, three were good and 53 were moderate. The three good were Grizedale Lea Reservoir, Langthwaite Reservoir and a tiny pond on Cockerham Marsh.

Of the 6 groundwater catchments, 4 were good and 2 poor.

In terms of the ecological classification alone, the standards were mostly better than for the overall quality. While most of the chemical classification standards achieved were good, there were some that completely failed to meet the required standard. These can be seen in the Microsoft Power BI slides.

Cycle 2 is the 2nd phase of river basin planning of the WFD running from the publication of river basin plans in 2015 until 2021. Cycle 1 was the 1st cycle of river basin planning of the WFD running from the publication of river basin plans in 2009 until 2015.

Visualisation of the results

We have included slides in a Microsoft Power BI dashboard to indicate the water quality in rivers and lakes. The lakes and reservoirs appear on the second slide. The software has caused the shading to fill-in concave sections of a river's flow, and this looks slightly strange, but makes the shading symbol stand out rather better and forms a larger area for pointing at and selecting. It does not show the groundwater catchment classifications. The separate classification items for chemical, ecological and overall standards for the years 2013 to 2016 may be seen.


Our river map uses the Environment Agency catchments of water bodies to allocate data to river sections derived from a different source, namely the Ordnance Survey Strategi 1:250,000 scale mapping. Some of the tidal river sections are classified as 'Transitional', and can apply to the river estuaries rather than it's tributaries, but this is the result that appears after a rather complicated geographical overlaying process. The river catchments may overlap the transitional and groundwater aquifer catchments, so we have tried to show the sections relating to river catchments where possible. We have also not included canals, because the standards they may indicate probably only apply to the rivers in that catchment.

There are classification items for both ecological and chemical standards, and these are split into many very detailed items. All of the details can be found on the Environment Agency Catchment Data Explorer: http://environment.data.gov.uk/catchment-planning/ and standards applying to all the years the WFD has been in force can be obtained.

Page created August 2018