South West Water sustainability score: 49/100
Leading practice starts at 60. The highest score on SINK is 71.
South West Water Limited supplies water and sewerage services in Devon and Cornwall and, since its combination with Bristol Water, water in the Bristol area. It is part of Pennon Group plc, was incorporated in 1989 and is headquartered in Exeter.
More about South West Water
Its filed accounts for the year to 31 March 2026 report revenue of £939.2m and an average of 2,695 employees.
Founded 1989Head office Exeter, United KingdomStaff ~2,695Revenue £939.2M (FY2025/26, year to 31 March 2026)Website ↗
Pennon group Scope 1 and 2 emissions, assured by Jacobs, fell about 4% in 2025/26, mainly because more renewable electricity was bought for the Bristol Water region, and South West Water's electricity is backed by renewable energy certificates. The Environment Agency rated it 2 stars for 2024, with 189 sewerage pollution incidents, 4 of them serious. In March 2026 it pleaded guilty to 18 charges, including 231 untreated sewage discharges onto Harlyn beach, and in September 2026 it was fined £7.87m. An Environment Agency case also covered illegal spills from its Bodmin works into the River Camel special area of conservation.
South West Water scores 49/100 (Making progress) on SINK's independent climate assessment, scored from public data only. Scores are free. Nobody can pay to change a score, speed it up or hide it. Last verified October 2026.
That places South West Water joint 179th of 1,023 companies scored, and 2nd of 11 in Water & Sewerage.
What is South West Water doing well, and where does it fall short?
Strongest on Carbon Footprint: Operations and Targets & Commitments (8/10, 7/10). Weakest on Water Impact and Controversies & Red Flags (2/10, 2/10).
Where South West Water lost points
For each question that lost points, the evidence our public rubric looks for that we didn't find.
What would raise this score
- Its effect on waterMonitor its water use and take measures to reduce it.
- Its record on controversiesDeal with the findings under question 10, in public.
- How it uses materials and handles wasteReport measurable waste or recycling targets publicly.
Every question that lost points
- Emissions from its own operations8/10No verified figures published with their method and a falling trend.
- Emissions from its supply chain6/10No full value-chain map or supplier engagement programme.
- Whether its emissions are falling6/10No consistent fall over several years across its operations and supply chain.
- How clean its energy is6/10Less than 90% of its energy shown to be renewable.
- Its effect on nature5/10Its effect on nature isn't measured or independently verified.
- How it uses materials and handles waste4/10No measurable waste or recycling targets reported publicly.
- Its effect on water2/10No monitoring of water use, or no measures to reduce it.
- Its climate targets7/10No validated long-term net zero target.
- How openly it reports7/10No annual impact report, or no pay linked to climate targets.
- Its record on controversies2/10Points deducted for controversies or its business model. The finding is under question 10.
A score changes when the evidence does. We use new published evidence at the next rescore. Anyone can send us new evidence, free. How to send it.
How is South West Water's SINK score calculated?
Same ten questions for every company. No private weighting.
SINK = (0.3 × Base + 0.7 × Performance) × ScaleWhat evidence is South West Water's score based on?
9 sources used in this assessment. All publicly available. Each row shows which of the ten questions it informed.
56% of them were published by South West Water itself; the rest come from independent sources.
“This is our fifth year of voluntarily reporting against the TNFD framework”
“Group Scope 1 and 2 GHG emissions and energy use, together with selected Scope 3 GHG emissions, have been independently assured by Jacobs”
“The Company has taken advantage of the exemption offered under the Companies Act 2006 and has not reported details of Greenhouse gas emissions”
“The water company started its new electricity contract with renewable energy supplier, ENGIE, last month (April 2022)”
“Pennon has received gold standard validation for its ambitious targets to reduce greenhouse gas emissions by the end of March 2033.”
“Of the charges, 17 are for illegal discharge activities including sewage discharges”
“189 actual incidents (needed 35 or fewer to be rated as green)”
“ranked South West Water lowest overall among English water companies across a series of environmental and affordability measures”
“South West Water has been fined more than £7.8m after a judge found that its conduct amounted to "reckless failures"”
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How does South West Water compare with other water & sewerage companies?
Where South West Water sits among water & sewerage peers.
Among the 11 major water & sewerage brands we've scored, South West Water sits 2nd of 11.
Who scores higher in Water & Sewerage?
The one company in the sector scoring above South West Water.
See the full Water & Sewerage table →Which companies moved this week, and why.
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