What is Severn Trent Water's GWSS score?

Severn Trent Water scores 58.2/100 on the Gera Water Service Score (GWSS) in 2024-25 — Average (grade C), ranking #15 of 19 UK water companies. The score combines leakage (98 l/p/d, weight 40%), supply interruptions (4 mins, weight 30%), and water quality CRI (10.32, weight 30%) from Ofwat APR 2024-25 and DWI data.

How much water does Severn Trent Water leak?

Severn Trent Water lost 98 litres of water per property per day through leaks in 2024-25, below the England and Wales average of 109 l/p/d. Source: Ofwat Annual Performance Report 2024-25, via DiscoverWater.co.uk (OGL v3.0).

How often does Severn Trent Water cause supply interruptions?

In 2024-25, Severn Trent Water customers experienced an average of 00:04:34 of lost water supply per property from interruptions lasting 3+ hours — better than the national average of 22 mins. Source: Ofwat APR 2024-25 via DiscoverWater.co.uk.

What is Severn Trent Water's Compliance Risk Index (CRI)?

Severn Trent Water's CRI in 2024 was 10.32, above the England and Wales average of 3.72. The CRI measures overall performance against national drinking water quality standards (lower = fewer compliance failures). Source: Drinking Water Inspectorate (DWI), Jan–Dec 2024, via DiscoverWater.co.uk.

How has Severn Trent Water's water quality changed over the past 4 years?

Severn Trent Water's CRI (Compliance Risk Index) over the past 4 years: 2024: 10.32, 2023: 5.65, 2022: 6.19, 2021: 10.32. Lower CRI = fewer quality compliance failures. Source: Drinking Water Inspectorate (DWI), via DiscoverWater.co.uk.

GeraMarket / UK water company performance / Severn Trent Water

Severn Trent Water: Performance Report

Rank #15 of 19 UK water companies · GWSS 58.2/100 (Average) · Leakage 98 l/p/d · Interruptions 00:04:34/property · CRI 10.32 (Ofwat APR 2024-25 / DWI 2024)

How does Severn Trent Water perform compared to other UK water companies?

In Ofwat APR 2024-25 / DWI 2024, Severn Trent Water ranks #15 of 19 UK water companies with a Gera Water Service Score (GWSS) of 58.2/100 — Average, 12.6 points below the national median of 70.8/100. Key metrics: leakage 98 l/p/d, supply interruptions 00:04:34/property, Compliance Risk Index 10.32 (Ofwat APR / DWI 2024, OGL v3.0).

Source:Ofwat APR 2024-25 + DWI CRI 2024 (via DiscoverWater.co.uk)·as of Ofwat APR 2024-25 / DWI 2024updated annually (last: 20 June 2026)

Gera Water Service Score58.2 / 100Severn Trent Water — Average (grade C) · #15 of 19 UK water companies · Ofwat APR 2024-25 / DWI 2024How this index is calculated

Reference period: Ofwat APR 2024-25 / DWI 2024· Ofwat APR 2024-25 + DWI CRI 2024 · Open Government Licence v3.0 · Midlands

Leakage score

67.6/100

98 l/p/d

E&W avg: 109

▼ below avg · weight 40%

Interruptions score

98.2/100

00:04:34

E&W avg: 22 mins

▼ below avg · weight 30%

Water quality score

5.7/100

CRI 10.32

E&W avg: 3.72

▲ above avg · weight 30%

Severn Trent Water performance figures (Ofwat APR 2024-25 / DWI 2024)

Severn Trent Water — Ofwat APR 2024-25 + DWI CRI 2024
Measure	Value	vs England & Wales
Gera Water Service Score (GWSS)	58.2/100	Average (grade C)
Overall rank	#15 of 19	vs national median GWSS 70.8/100
Leakage	98 l/p/d	▼ below E&W avg 109 l/p/d
Supply interruptions	00:04:34	▼ below E&W avg 22 mins
CRI (water quality)	10.32	▲ above E&W avg CRI 3.72
Region	Midlands	Ofwat regulatory area

Severn Trent Water CRI trend (2021–2024)

Compliance Risk Index (lower = better). Source: Drinking Water Inspectorate (DWI) via DiscoverWater.co.uk.

Year	CRI	vs E&W avg (3.72)
2024	10.32	▲ above avg
2023	5.65	▲ above avg
2022	6.19	▲ above avg
2021	10.32	▲ above avg

Compare Severn Trent Water with other water companies

Sort by GWSS, leakage, interruptions, or water quality to see how your company compares across all metrics.

Severn Trent WaterGWSS 58.2/100 · leakage 98 l/p/d · interruptions 00:04:34 · CRI 10.32

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Overall GWSS (highest first)

Company	GWSS	Leakage	Interruptions	CRI	Grade
#1SES Water	93.2/100	68 l/p/d	00:26:40	0.00	A
#2Bristol Water	89.7/100	68 l/p/d	00:06:49	2.84	A
#3Portsmouth Water	88.9/100	90 l/p/d	00:02:01	0.45	A
#4Anglian Water	87.1/100	80 l/p/d	00:06:51	2.11	A
#5Affinity Water	84/100	95 l/p/d	00:03:21	1.44	B
#6South West Water	79.5/100	102 l/p/d	00:14:44	1.19	B
#7Wessex Water	77.9/100	108 l/p/d	00:10:00	1.31	B
#8South East Water	75.8/100	96 l/p/d	00:44:06	1.09	B
#9Cambridge Water	73.1/100	80 l/p/d	00:15:04	6.58	B
#10Yorkshire Water	70.8/100	111 l/p/d	00:08:27	3.61	B
#11Essex and Suffolk Water	69.4/100	64 l/p/d	00:04:40	10.94	C
#12South Staffs Water	64.3/100	103 l/p/d	00:15:04	6.58	C
#13Hafren Dyfrdwy	64.2/100	145 l/p/d	00:11:11	1.10	C
#14Thames Water	62.7/100	143 l/p/d	00:09:35	2.04	C
#15Severn Trent Water	58.2/100	98 l/p/d	00:04:34	10.32	C
Leakage score 67.6/100 98 litres/property/day Interruptions score 98.2/100 00:04:34 per property Water quality score 5.7/100 CRI 10.32 CRI history (2021–2024, lower = better): 2024: 10.32 2023: 5.65 2022: 6.19 2021: 10.32 Full Severn Trent Water report →
#16Northumbrian Water	58/100	94 l/p/d	00:04:40	10.94	C
#17Southern Water	50/100	89 l/p/d	02:21:50	3.82	D
#18United Utilities	48.2/100	119 l/p/d	00:14:17	10.28	D
#19Dŵr Cymru Welsh Water	19.4/100	169 l/p/d	02:17:44	4.18	E

Showing 19 of 19 UK water companies. Source: Ofwat APR 2024-25 + DWI CRI 2024, via DiscoverWater.co.uk (OGL v3.0).

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Frequently asked questions

What is Severn Trent Water's GWSS score?: Severn Trent Water scores 58.2/100 on the Gera Water Service Score (GWSS) in 2024-25 — Average (grade C), ranking #15 of 19 UK water companies. The score combines leakage (98 l/p/d, weight 40%), supply interruptions (4 mins, weight 30%), and water quality CRI (10.32, weight 30%) from Ofwat APR 2024-25 and DWI data.
How much water does Severn Trent Water leak?: Severn Trent Water lost 98 litres of water per property per day through leaks in 2024-25, below the England and Wales average of 109 l/p/d. Source: Ofwat Annual Performance Report 2024-25, via DiscoverWater.co.uk (OGL v3.0).
How often does Severn Trent Water cause supply interruptions?: In 2024-25, Severn Trent Water customers experienced an average of 00:04:34 of lost water supply per property from interruptions lasting 3+ hours — better than the national average of 22 mins. Source: Ofwat APR 2024-25 via DiscoverWater.co.uk.
What is Severn Trent Water's Compliance Risk Index (CRI)?: Severn Trent Water's CRI in 2024 was 10.32, above the England and Wales average of 3.72. The CRI measures overall performance against national drinking water quality standards (lower = fewer compliance failures). Source: Drinking Water Inspectorate (DWI), Jan–Dec 2024, via DiscoverWater.co.uk.
How has Severn Trent Water's water quality changed over the past 4 years?: Severn Trent Water's CRI (Compliance Risk Index) over the past 4 years: 2024: 10.32, 2023: 5.65, 2022: 6.19, 2021: 10.32. Lower CRI = fewer quality compliance failures. Source: Drinking Water Inspectorate (DWI), via DiscoverWater.co.uk.

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Contains public sector information published by Ofwat / Drinking Water Inspectorate and licensed under the Open Government Licence v3.0. Source: Ofwat APR 2024-25 + DWI CRI 2024 (via DiscoverWater.co.uk) (Ofwat APR 2024-25 / DWI 2024, published June 2026 (Ofwat APR 2024-25)).