Research and analysis

State of the water environment indicator B3: supporting evidence

Updated 22 May 2023

Applies to England

In the 25 Year Environment Plan, water theme indicators are:

  • B1. Pollution loads entering waters
  • B2. Serious pollution incidents to water
  • B3. State of the water environment
  • B4. Bathing waters
  • B5. Water bodies achieving sustainable abstraction criteria
  • B6. Naturalness of water
  • B7. Health of freshwaters assessed through fish populations

Related indicators for water use, quantity and availability are:

  • E8. Efficient use of water
  • F3. Disruption or unwanted impacts caused by drought

F3 is also an indicator within resilience to natural hazards.

Indicators within managing exposure to chemicals and minimising waste are:

  • H3. Emissions of mercury and persistent organic pollutants to the environment
  • H4. Exposure and adverse effects of chemicals on wildlife in the environment
  • J5. Prevent harmful chemicals from being recycled

This evidence summary supports the B3 state of the water environment indicator.

State of the water environment in England: data summary

All surface waters

16% of assessed surface waters and 79% of individual tests achieve good ecological status.

Rivers

14% of assessed rivers are at good ecological status.

Biology

Fish: 42% at good status.

Invertebrates: 76% at good status.

Macrophytes and phytobenthos: 45% at good status.

Physical modification

Morphology: 49% at good status.

Flow regime: 88% at good status.

Water quality

Dissolved oxygen: 82% at good status.

Ammonia: 92% at good status.

Phosphorus: 45% at good status.

Hazardous substances

Chemical status: 0% at good status.

Chemical status excluding ubiquitous, persistent, bioaccumulative, toxic substances (uPBTs): 93% at good status.

Lakes

14% of assessed lakes are at good ecological status.

Biology

Phytoplankton: 52% at good status.

Macrophytes and phytobenthos: 29% at good status.

Physical modification

Morphology: 97% at good status.

Water quality

Total phosphorus: 25% at good status.

Total nitrogen: 45% at good status.

Hazardous substances

Chemical status: 0% at good status.

Chemical status excluding uPBTs: 100% at good status.

Estuaries

19% of assessed estuaries are at good ecological status.

Biology

Fish: 77% at good status.

Invertebrates: 67% at good status.

Saltmarsh: 36% at good status.

Seagrass: 90% at good status.

Eutrophication (combined assessment)

Rating Certain there is no problem Uncertain there is a problem Quite certain there is a problem Very certain there is a problem Total
Percentage 43% 41% 13% 3% 100%

Hazardous substances

Chemical status: 0% at good status.

Chemical status excluding uPBTs: 92% at good status.

Coastal waters

45% of assessed coastal waters are at good ecological status.

Biology

Invertebrates: 87% at good status.

Saltmarsh: 50% at good status.

Seagrass: 83% at good status.

Eutrophication (combined assessment)

Rating Certain there is no problem Uncertain there is a problem Very certain there is a problem Total
Percentage 71% 27% 2% 100%

Hazardous substances

Chemical status: 0% at good status.

Chemical status excluding uPBTs: 100% at good status.

Groundwater

Quantity: 73% at good status.

Quality: 45% at good status.

Drinking water protected areas

Surface water

47% not at risk of deterioration.

Groundwater

53% not at risk of deterioration.

Designated bathing waters

Status Excellent Good Sufficient Poor Total
Percentage 72% 21% 4% 3% 100%

Shellfish waters

Status Pass Fail Total
Percentage 26% 74% 100%

Protected nature sites

Condition Favourable Unfavourable recovering Unfavourable no change Unfavourable declining Total
Percentage 45% 43% 6% 6% 100%

About the data

Figures are percentages of water bodies assessed and where referred to as ‘at good status’ this is good or better status.

The 2019 water body classification data is published on data.gov.uk.

For other data contact enquiries@environment-agency.gov.uk

Surface waters: ecological and chemical classification

Ecological status

Ecological status is assigned using various water, habitat and biological quality tests. Failure of any one individual test means that the whole water body fails to achieve good or better ecological status or potential (the ‘one out all out’ rule).

The ‘State of the water environment in England: data summary’ section shows data for each surface water type – representative elements that are tested to assess the condition of the water body, reflecting water quality and hydromorphology.

Ecological status is measured in 5 classes (bad to high).

2019 classification results show surface water ecological status has remained stable and 16% of surface water bodies achieved good or better ecological status or potential, the same as in 2016.

Classification Description Percentage in status
High Natural or almost natural state with no, or only minor evidence of distortion. Less than 1%
Good Slight change from natural state as a result of human impact. 16%
Moderate Moderate change from natural state as a result of human impact. 63%
Poor Major change from natural state as a result of human activity. 17%
Bad Severe change from natural state as a result of human activity. 3%

Chemical status

Chemical status is calculated by assessing 52 different chemical elements (individual and groups of chemicals). Water bodies are classified as good or failing.

For 2019 chemical classifications, new assessments for uPBTs were included, as well as new standards, improved techniques and methods.

This resulted in 0% surface water bodies meeting the criteria for achieving good chemical status in 2019, compared to 97% pass in 2016.

If we exclude the new assessments for uPBTs then only 6.2% of surface water bodies fail the chemical tests and 93.8% pass.

Current data is shown as ‘Hazardous substances’ in the ‘State of the water environment in England: data summary’ section. This shows the water body results for rivers, lakes, estuaries and coasts for chemical status with and without the uPBTs.

The 2019 water body classification data is published on data.gov.uk.

Check how to find information in the 2022 update to the river basin management plans.

You can use the Catchment Data Explorer to find and download data.

Surface waters: new monitoring approach and data for future reporting

Under our current approach to monitoring and reporting water status, it is hard to separate out the evidence of environmental change over time from the evidence associated with identifying problems and targeting solutions. A fresh approach to assessing environmental change in the water environment is needed.

To enable us to do that, the government has funded the Natural Capital and Ecosystem Assessment programme (NCEA).

The NCEA will provide a set of robust environmental monitoring networks and integrated assessments designed to evaluate and track changes in the environment’s natural capital, at national and regional scales.

The data and evidence from the new networks will be included in 25 Year Environment Plan and new Environmental Improvement Plan 2023 reporting on the condition of the water environment in future.

Surface water quality and quantity data will be provided by the River Surveillance Network and equivalent networks being developed for small streams, lakes and estuaries and coasts.

There will also be a groundwater network which will provide condition data for this water category.

This is a large and complex programme which is taking time to develop and phase in over the next few years.

Groundwater: ecological and chemical classification

Nitrate is the most common cause of groundwater test failure.

2015 2019
Failure of trend test due to nitrate 25.5% 26.9%
Failure of any test due to nitrate 36.9% 39.8%

Groundwater quantitative classification

Net increase in the number of groundwater bodies meeting good quantitative status.

Year Poor Good Total
2009 40% 60% 100%
2015 31% 69% 100%
2019 27% 73% 100%
2022 27% 73% 100%

Groundwater chemical classification

Net decrease in the number of groundwater bodies meeting good chemical status.

Year Poor Good Total
2009 42% 58% 100%
2015 47% 53% 100%
2019 55% 45% 100%

Substances causing failure for 2019 across all tests and groundwater bodies

Substance Test failure figure
Nitrate 108
Orthophosphate 36
Copper 35
Chloride 35
Zinc 34
Sulphate 34
Iron 34
Manganese 33
Nickel 22
Ammoniacal nitrogen 14
Solvents 12
Lead 11
Electrical conductivity 9
Aluminium 9
Pesticides 8
Cadmium 8
Arsenic 8
Boron 6
Sodium 3
Other metals 2
Mecoprop 2
Hydrocarbons 2
Bromate 2
Polycyclic aromatic hydrocarbons (PAHs) 1
Per- and polyfluoroalkyl substances (PFAS) 1
Fluoride 1
Chromium 1
Antimony 1

Groundwater classification status and objectives data is published on data.gov.uk.

Drinking water protected areas

Reservoirs, lakes, rivers and groundwater, from which raw water is abstracted for human consumption at a rate of 10 m3 per day or more or serving more than 50 people are Drinking Water Protected Areas (DrWPAs). These criteria are defined in the Water Environment (Water Framework Directive) (England and Wales) Regulations 2017. Safeguard zones are areas connected to the DrWPA where pollution needs to be reduced to protect the drinking water resource.

For surface water DrWPAs the safeguard zones cover the upstream catchment areas which can include more than one DrWPA. For groundwaters the DrWPA is a large underground aquifer which may include multiple safeguard zones to protect springs or boreholes.

Safeguard zones can cover more than one pollutant type and are established when raw water quality is deteriorating, or is likely to deteriorate in the future (that is ‘at risk of deterioration’). Measures aiming to avoid deterioration, reducing the level of water treatment required to produce drinking water, are set out in Safeguard Zone Action Plans.

Surface water

There are 450 surface water DrWPAs.

There are 240 at risk of deterioration.

There are 148 surface water safeguard zones.

Reasons for establishing surface water safeguard zones:

  • pesticides: 50%
  • sediment: 22%
  • algae: 19%
  • nitrate: 5%
  • microbiology: 2%
  • other: 2%

Groundwater

There are 271 groundwater DrWPAs.

There are 127 at risk of deterioration.

There are 251 groundwater safeguard zones.

Reasons for establishing groundwater safeguard zones:

  • nitrate: 73%
  • pesticides: 13%
  • solvents: 8%
  • microbiology: 3%
  • sediment: 1%
  • other: 2%

European protected nature sites for water and wetlands

Underlying SSSI unit condition by habitat

Rivers

Condition Favourable Unfavourable recovering Unfavourable no change Unfavourable declining Total
Percentage 9.9% 51.3% 36.6% 2.2% 100%

Lakes

Condition Favourable Unfavourable recovering Unfavourable no change Unfavourable declining Total
Percentage 58.8% 13% 19.9% 8.3% 100%

Estuaries and coasts

Condition Favourable Unfavourable recovering Unfavourable no change Unfavourable declining Total
Percentage 59.4% 31.9% 2.6% 6.1% 100%

Wetlands

Condition Favourable Unfavourable recovering Unfavourable no change Unfavourable declining Total
Percentage 13.3% 73.2% 10.4% 3.1% 100%

Condition change: all SSSI units underlying water-dependent habitats

Favourable:

  • 240,179 hectares (ha)
  • 45%

Unfavourable recovering:

  • 229,298ha
  • 43%

Unfavourable no change:

  • 29,860ha
  • 6%

Unfavourable declining:

  • 32,229ha
  • 6%

About the data

This data on European protected nature sites for water and wetlands:

  • includes rivers, lakes, wetlands, estuaries and coasts, and other water-dependent habitats
  • includes sites designated for birds that may be in favourable condition without assessment of water quality
  • excludes adverse condition reasons that are unrelated to Water Framework Directive drivers
  • was retrieved in November 2022
  • is a derived analysis, not a published dataset

For more information on this data contact Natural England.

Key issues and sectors affecting water bodies in England

Sector Physical modifications Pollution from waste water Pollution from towns, cities and transport Changes to natural flow and levels of water Non-native invasive species Pollution from rural areas Pollution from abandoned mines
Agriculture 12.9% 0.1% 0.1% 1.3%   40%  
Industry 1.9% 0.5% 3.4% 0.4%      
Mining and quarrying 0.1%   0.1%       3.2%
Navigation 1.9%     0.1%      
Urban and transport 10.9% 0.6% 10.1%        
Water industry 7.9% 35% 0.8% 9.8%      
Local and central government 14.3% 0.2%   0.2%      
Domestic general public 0.3% 1.1% 6.4%        
Recreation 2.9%   0.2% 0.1%      
Waste treatment and disposal   0.1% 0.3%        
No sector responsible 0.1%   0.1%   23%    

Percentage of water bodies impacted by each issue

Issue Percentage of water bodies impacted
Physical modifications 41%
Pollution from waste water 36%
Pollution from towns, cities and transport 18%
Changes to natural flow and levels of water 15%
Non-native invasive species 23%
Pollution from rural areas 40%
Pollution from abandoned mines 3%

Percentage of water bodies impacted by each sector

Sector Percentage of water bodies impacted
Agriculture 45%
Industry 6%
Mining and quarrying 3%
Navigation 2%
Urban and transport 18%
Water industry 44%
Local and central government 14%
Domestic general public 8%
Recreation 3%
Waste treatment and disposal 0.3%
No sector responsible 23%

Sectors and challenges preventing good water quality in England

Most of the data used to produce the tables in the ‘Key issues and sectors affecting water bodies in England’ section are taken from the 2019 set of probable and confirmed reasons for not achieving good status (RNAGs), linked to 2016 WFD classifications. This is with the exception of the following.

  1. Changes to the natural flows and levels of water. The data are for those water bodies that do not have sustainable levels of abstractions. The sector contributions include suspected, probable and confirmed RNAGs.

  2. Invasive non-native species. This uses Environment Agency monitoring data and are for water bodies that have specific invasive non-native species present which we consider to be contributing to the water body not achieving good ecological status.

‘No sector responsible’ covers those situations where it is not possible to assign the failure to achieve good status to the activities of a specific sector. We have used this category mainly for invasive non-native species. Whilst the speed of their spread can be increased by poor practice, it is not possible to say whether their presence in a particular water body is ‘natural’ or due to someone’s actions.

Around 6% of water bodies have one or more RNAGs where the sector responsible is still under investigation. Around 5% of water bodies have one or more RNAGs caused by a different sector to those listed in the table. These are mainly where the issue is physical modification.

For more information on this data please contact the Environment Agency.