Derwent Derbyshire management catchment: baseline length of rivers and estuaries polluted by abandoned metal mines
Published 12 March 2025
Applies to England
© Crown copyright 2025
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This is one of 20 reports, one for each polluted management catchment, on the water quality monitoring undertaken by the Environment Agency to determine the baseline length of rivers and estuaries considered polluted by any of the Environment Act target substances from abandoned metal mines in 2022.
A length of river or estuary is considered polluted where the concentration of one or more of the 6 target substances (arsenic, cadmium, copper, lead, nickel and zinc) exceeds the relevant Environmental Quality Standard (EQS). EQS concentrations are based on ecotoxicology data and set by government at a level that should prevent harmful environmental impacts. When the concentration of a substance in a water sample is higher than the EQS, adverse impacts on the aquatic ecosystem can be expected. The relevant EQS for each target substance are set out in The Water Framework Directive (Standards and Classification) Directions (England and Wales) 2015.
The purpose of calculating this baseline was to enable measurement of the statutory abandoned metal mines target set out in Part 4 of the Environmental Targets (Water) (England) Regulations 2023. This regulation requires that the combined length of English rivers and estuaries polluted by the target substances from abandoned metal mines is, by 31 December 2038, at least 50% lower than the baseline.
In the Derwent Derbyshire management catchment, the baseline length of polluted rivers for the abandoned metal mines water target is 143km. We will aim to identify the key sources of metal pollution in this management catchment by carrying out detailed monitoring investigations.
You can find further background and context on the Environment Act abandoned metal mines water target in the national baseline report which should be read together with this report.
The Derwent Derbyshire management catchment
The Derwent Derbyshire management catchment covers an area of approximately 1,190km2. The catchment extends from the Peak District National Park in the north down to south of the city of Derby. Please go to Derwent Derbyshire Management Catchment on the Catchment Data Explorer for an interactive map showing the 3 operational catchments that make up the Derwent Derbyshire management catchment. The boundary of the Derwent Derbyshire management catchment and all 3 operational catchments are highlighted in Figure 1.
Metal mining in the Derwent Derbyshire management catchment
The Peak District Orefield is one of the largest in England, with the lead mining industry dating from Roman times until the 19th century, with its height being in the 17th and 18th centuries. There is a legacy of thousands of mineshafts and hundreds of mine drainage adits (known locally as soughs) which were dug to facilitate extraction of minerals such as lead ore from veins contained mainly in the Carboniferous Limestone bedrock. In recent times, mineral extraction in the area has focussed on minerals previously discarded, such as barytes and fluorspar.
Figure 1 shows the locations of mineral veins, known mine water discharges, closed mine waste facilities known to be causing serious environmental harm, and areas of abandoned mine wastes (mining spoil) in the Derwent Derbyshire management catchment.
This information has been gathered from various sources including:
- BGS Geological mapping - GeoIndex - British Geological Survey
- Prioritisation of abandoned non-coal mine impacts on the environment
- Inventory of closed mining waste facilities causing serious environmental impacts
- Defra-funded ‘Source apportionment of pollution from non-coal mines’ research project by Newcastle University and Hull University (unpublished)
- Environment Agency water quality data archive
As we can see in Figure 1, most of the historical mining activities in the Derwent Derbyshire management catchment were concentrated in the Derwent Upper and Derwent Middle operational catchments, however pollution from these mines extends into the downstream operational catchments.
Figure 1. Map showing the abandoned metal mines, mineral veins and baseline river monitoring sites in the Derwent Derbyshire management catchment
© Environment Agency
The tables below list the catchments (surface water bodies) that are polluted by target substances from abandoned metal mines in the Derwent Derbyshire management catchment. These tables highlight where there are known point sources (mine adits/mine drainage levels) and diffuse sources (mine wastes/spoil heaps) within the catchment. The Environment Agency is continuing to investigate point and diffuse sources within the Derwent Derbyshire management catchment by undertaking a series of catchment characterisation studies. These studies will help us identify which sources of metals need to be tackled to achieve the long-term statutory target.
Derwent Upper operational catchment: sources of metal pollution
Table 1 summarises which type of pollution sources from abandoned metal mines have been identified within the catchments (surface water bodies) in the Derwent Upper operational catchment.
Table 1. Summary of metal pollution sources in the Derwent Upper operational catchment
| Catchment (Surface water body) | Point sources of pollution | Diffuse sources of pollution |
|---|---|---|
| Peakshole Water from Source to R Noe | Yes | Yes |
| Noe from Peakshole Water to R Derwent | Yes | Yes |
| Wye from Monk’s Dale to R Derwent | Further investigation required | Further investigation required |
| Lathkill from Source to R Bradford | Further investigation required | Further investigation required |
| Lathkill from R Bradford to R Wye | Further investigation required | Further investigation required |
| River Bradford from Source to River Lathkill | Further investigation required | Further investigation required |
| Derwent from Wye to Amber | Further investigation required | Further investigation required |
Derwent Middle operational catchment: Sources of metal pollution
Table 2 summarises which type of pollution sources from abandoned metal mines have been identified within the catchments (surface water bodies) in the Derwent Middle operational catchment.
Table 2. Summary of metal pollution sources in the Derwent Middle operational catchment
| Catchment (Surface water body) | Point sources of pollution | Diffuse sources of pollution |
|---|---|---|
| Amber from Source to Press Brook | Further investigation required | Further investigation required |
Derwent Lower operational catchment: sources of metal pollution
Table 3 summarises which type of pollution sources from abandoned metal mines have been identified within the catchments (surface water bodies) in the Derwent Lower operational catchment
Table 3. Summary of metal pollution sources in the Derwent Lower operational catchment
| Catchment (Surface water body) | Point sources of pollution | Diffuse sources of pollution |
|---|---|---|
| Derwent from Bottle Brook to Trent | None identified: sources are upstream | None identified: sources are upstream |
Baseline monitoring
The objective of the baseline monitoring was to establish the upstream and downstream extent of surface waters polluted by the target substances from abandoned metal mines. We selected the baseline monitoring sites by first completing a desk study to review previous water quality data, maps and reports. We then made initial site visits to collect samples and to assess the suitability of the site for continued sampling. Generally, at least twelve water quality samples were then collected from each monitoring site.
Within the Derwent Derbyshire management catchment, water quality monitoring was undertaken in all 3 operational catchments.
In total, 30 monitoring sites were selected across the Derwent Derbyshire management catchment to determine the baseline length of rivers polluted by target substances from abandoned metal mines. The locations of these monitoring sites are shown in Figure 1.
Water quality data collected between 1 January 2022 and 31 March 2024 have been used to determine and validate the baseline length of rivers and estuaries considered polluted in 2022. The length of rivers polluted by abandoned metal mines fluctuates in response to natural variation in rainfall and river flows. However, this length will not materially change unless remediation measures like mine water treatment schemes or diffuse interventions are installed to decrease inputs of metals. Therefore, data collected after 31 December 2022 are considered to be representative of rivers, provided no new remediation measures had been constructed since 2022. No new remediation measures have been constructed in the Derwent Derbyshire management catchment since 2022.
Water quality monitoring results
In the Derwent Derbyshire management catchment, the target substances measured were cadmium, copper, lead, nickel and zinc. We did not undertake testing for arsenic in this management catchment since historical monitoring data and knowledge of the local geology across the catchment indicated that no rivers are polluted by arsenic in this management catchment.
The baseline water quality data for all monitoring sites are available on the Environment Agency’s public water quality archive.
For a river water quality sample to be considered polluted, concentrations of one or more of the target substances must exceed the relevant EQS set by government when assessed as an “annual average”. The EQS are set out in The Water Framework Directive (Standards and Classification) Directions (England and Wales) 2015.
The EQS are derived using ecotoxicology data and set at a level that should prevent harmful environmental impacts. When the concentration of a substance in a water sample is higher than the EQS, adverse impacts on the aquatic ecosystem can occur, and the sample is considered to be polluted.
To understand the severity of pollution, we calculated a numeric “pollution level” by dividing the measured concentration of the target substances by the EQS. If the pollution level is greater than 1, the monitoring site is considered polluted by that target substance. Therefore, the higher the numeric pollution level, the greater the likelihood of harm to aquatic life.
Baseline polluted river length: Derwent Derbyshire management catchment
Our detailed monitoring across a range of flow conditions between January 2022 and March 2024 shows that in the Derwent Derbyshire management catchment, the baseline length of polluted rivers for the abandoned metal mines target is 143km.
Figure 2 shows the rivers in the Derwent Derbyshire management catchment that are polluted by target substances from abandoned metal mines.
Figure 2. The baseline length of rivers polluted by target substances from abandoned metal mines in the Derwent Derbyshire management catchment is 143km
© Environment Agency
Table 4 shows the river length (in km) that are polluted by each of the target substances within the Derwent Derbyshire management catchment.
In general, the most polluted rivers are impacted by more than one target substance.
Table 4. River length (in km) polluted by each of the target substances within the Derwent Derbyshire management catchment.
| Target substance | Polluted river length (km) | Pollution level: less than 3 times | Pollution level: 3 to 5 times | Pollution level: greater than 5 times |
|---|---|---|---|---|
| Cadmium (Cd) | 112 | 101 | 6 | 9 |
| Lead (Pb) | 26 | 11 | 15 | 0 |
| Nickel (Ni) | 0 | 0 | 0 | 0 |
| Zinc (Zn) | 107 | 74 | 27 | 8 |
| Copper (Cu) | 0 | 0 | 0 | 0 |
Rivers polluted by abandoned metal mines: Derwent Derbyshire management catchment
Derwent upper operational catchment: baseline polluted rivers
Several tributaries of the River Derwent including Peakshole Water, Bradwell Brook, Dale Brook, the River Wye, River Lathkill, River Bradford and are polluted by zinc, cadmium and lead. In its upper reaches however, the River Derwent is polluted by cadmium only. Due to the input of several polluted tributaries the River Derwent becomes polluted by zinc.
Figure 3 shows the baseline polluted rivers in this operational catchment.
Figure 3. The baseline length of rivers polluted by target substances from abandoned metal mines in the Derwent upper operational catchment is 98km
© Environment Agency
It should be noted that due to close proximity of some of the sampling points to each other, some of the sampling point markers on this map (blue squares) may overlap.
Derwent Middle operational catchment: baseline polluted rivers
The main River Derwent is polluted along its length by zinc and cadmium to the point where the boundary of the downstream operational catchment (Derwent Lower) starts. A short stretch of the River Amber is also polluted by the same substances until the river enters Ogston Reservoir.
Figure 4 shows the baseline polluted rivers in this operational catchment.
Figure 4. The baseline length of rivers polluted by target substances from abandoned metal mines in the Derwent middle operational catchment is 21km
© Environment Agency
It should be noted that due to close proximity of some of the sampling points to each other, some of the sampling point markers on this map (blue squares) may overlap.
Derwent Lower operational catchment: baseline polluted rivers
The River Derwent remains polluted by zinc down to Borrowash approximately 10km above the confluence with the River Trent.
Figure 5 shows the baseline polluted rivers in this operational catchment.
Figure 5. The baseline length of rivers polluted by target substances from abandoned metal mines in the Derwent Derbyshire lower operational catchment is 24km
© Environment Agency
It should be noted that due to close proximity of some of the sampling points to each other, some of the sampling point markers on this map (blue squares) may overlap.