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.
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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. Fees pay for the review, never the result. Last verified October 2026.
That places South West Water joint 169th of 847 companies scored, and 2nd of 11 in Water & Sewerage.
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.
Its three lowest-scoring questions, and what the evidence didn't show.
The full reasoning is in the ten questions below.
Water UK member; no InfluenceMap climate-policy misalignment found.
No quantified waste-to-landfill, circularity or materials metrics with targets disclosed for South West Water in available sources.
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Get in touch →Strongest on Carbon Footprint — Operations and Targets & Commitments (8/10, 7/10). Weakest on Water Impact and Controversies & Red Flags (2/10, 2/10).
The one company in the sector scoring above South West Water.
See the full Water & Sewerage table →The formula and all 9 sources.
Same ten questions for every company. No private weighting.
SINK = (0.3 × Base + 0.7 × Performance) × Scale9 sources used in this assessment. All publicly available. Each row shows which of the ten questions it informed.
“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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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. Its filed accounts for the year to 31 March 2026 report revenue of £939.2m and an average of 2,695 employees.
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