Key facts and data from water company plans

Water companies submitted their business plans for 2025-2030 to us on 2 October 2023.

We have published key facts and data from their plans, including information on proposed increases in investment and customer bills. We are currently scrutinising the companies’ plans, including looking at their ambition for customers and the environment and the affordability of plans for customers.

The data for customer bills and expenditure allowances was updated on 8 May 2024 to reflect changes made to company business plans since 2 October 2023. The previously published data is still available. The other data is from the business plans as submitted on 2 October 2023.

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Customer bills

Water and wastewater companies

Actual average bill Proposed average bill Proposed increase in company bill
Water and wastewater companies 2024-25 2029-30 2029-30 vs 2024-25
Anglian Water £490.86 £573.06 16.75%
Dŵr Cymru £466.35 £601.86 29.06%
Hafren Dyfrdwy £396.37 £559.71 41.21%
Northumbrian Water £415.02 £471.47 13.60%
Severn Trent Water £402.63 £546.35 35.70%
Southern Water £420.35 £726.64 72.87%
South West Water £496.84 £596.04 19.97%
Thames Water* £435.55 £627.00 43.96%
United Utilities £442.45 £553.99 25.21%
Wessex Water** £508.36 £690.00 35.73%
Yorkshire Water £430.47 £569.40 32.27%
Weighted average bill £440.73 £584.74 32.68%

Water only companies

Actual average bill Proposed average bill Proposed increase in company bill
Water only  companies 2024-25 2029-30 2029-30 vs 2024-25
Affinity Water £191.72 £216.93 13.15%
Portsmouth Water £113.79 £134.84 18.50%
South East Water £230.24 £280.59 21.87%
South Staffs Water £160.96 £181.18 12.56%
SES Water £220.92 £260.14 17.75%
Weighted average bill £191.39 £222.67 16.34%

The proposed changes in bills do not take account of inflation.

*This amount includes the company’s proposed “deliverability adjustment mechanism” for 2025-30 which would cover £1.9bn of investment relating to its Water Industry National Environment Programme, the Industrial Emissions Directive, and the Security and Emergency Measures Direction. Thames Water explain that if all of the funding was approved for 2025-30, this could potentially lead to an average customer bill of £627 by 2030.

**Wessex Water explains that this amount reflects the additional costs of delivering the company’s full Water Industry National Environment Programme nutrients programme by 2030, rather than phasing some of this programme beyond this date (as proposed in Wessex Water’s October 2023 business plan). This would increase total expenditure to £5,416 million and average customer bills to £690 by 2030.

 

Expenditure allowances

More detailed breakdown available.

Water company PR19 Final Determinations – net total expenditure (£m, 2022-23 prices) PR24 Business Plan proposals – net total expenditure (£m, 2022-23 prices) % change between PR19 and PR24
Anglian Water 6,496 9,522 47%
Dŵr Cymru 3,575 5,627 57%
Hafren Dyfrdwy 210 256 22%
Northumbrian Water 3,491 6,020 72%
Severn Trent Water 7,520 13,316 77%
South West Water (inc. Bournemouth and Bristol) 2,832 4,469 58%
Southern Water 4,071 7,172 76%
Thames Water 11,721 21,403* 83%
United Utilities 6,846 13,831 102%
Wessex Water 2,522 5,416** 115%
Yorkshire Water 5,321 7,682 44%
Affinity Water 1,788 2,127 19%
Portsmouth Water 235 346 47%
South East Water 1,065 1,889 77%
South Staffs Water 678 817 21%
SES Water 310 413 33%
Industry total 58,681 100,305 71%

*This amount includes the company’s proposed “deliverability adjustment mechanism” for 2025-30 which would cover £1.9bn of investment relating to its Water Industry National Environment Programme, Industrial Emissions Directive, and Security and Emergency Measures Direction.

**This amount reflects the additional costs of delivering the full Water Industry Nation Environment Programme nutrients programme by 2030, rather than phasing some of this programme beyond this date (as proposed in Wessex Water’s October 2023 business plan).

 

Water supply interruptions

  Outturn Business Plan forecast
Water company Average minutes lost per property (hh:mm:ss)
2022-23
Average minutes lost per property (hh:mm:ss)
2029-30
Anglian Water 00:14:35 00:05:00
Dŵr Cymru 00:44:31 00:04:30
Hafren Dyfrdwy 00:16:39 00:05:00
Northumbrian Water 00:08:17 00:04:03
Severn Trent Water 00:09:10 00:05:00
South West Water (inc. Bournemouth and Bristol) 00:08:29 00:04:00
Southern Water 01:28:00 00:04:31
Thames Water 00:19:54 00:09:00
United Utilities 00:38:45 00:04:22
Wessex Water 00:04:10 00:05:00
Yorkshire Water 00:09:27 00:05:20
Affinity Water 00:12:53 00:03:40
Portsmouth Water 00:02:21 00:02:05
South East Water 03:02:21 00:10:14
South Staffs Water 00:04:29 00:02:30
SES Water 00:03:51 00:03:30
Sector average 00:26:12 00:05:28

Note: The performance commitment level on water supply interruptions for all companies for 2022-23 was 5 mins 45 seconds; for 2024-25 it is 5 minutes.

 

Leakage

  2022-23 outturn performance leakage cubic metre per kilometre mains, m3/km/d Leakage reduction from 2017-18 baseline, %

Water company 2022-23 2029-30
Anglian Water 4.65 4.5% 20.8%
Dŵr Cymru 9.08 -21.2% 17.3%
Hafren Dyfrdwy 5.41 20.1% 30.7%
Northumbrian Water 6.59 14.0% 22.9%
Severn Trent Water 8.69 7.5% 35.6%
South West Water (inc. Bournemouth and Bristol) 5.95 11.9% 35.1%
Southern Water 7.80 -5.8% 35.0%
Thames Water 19.41 11.4% 41.2%
United Utilities 9.87 5.9% 26.4%
Wessex Water 5.88 6.9% 21.2%
Yorkshire Water 8.76 12.4% 31.0%
Affinity Water 8.88 15.7% 29.4%
Portsmouth Water 9.51 0.6% 37.3%
South East Water 6.80 -6.4% 26.5%
South Staffs Water 9.04 13.1% 33.2%
SES Water 6.46 11.6% 31.0%
Sector average 8.80 7.0% 31.2%

Regional leakage breakdowns

  2022-23 outturn performance leakage cubic metre per kilometre mains, m3/km/d Leakage reduction from 2017-18 baseline, %

Region 2022-23 2029-30
South West Water (Bristol region) 5.68 10.0% 32.8%
South West Water (South West and Bournemouth regions) 6.05 12.5% 35.9%
Northumbrian Water (Essex and Suffolk region) 6.23 16.9% 23.6%
Northumbrian Water (Northern region) 6.78 12.5% 22.5%
South Staffs Water (Cambridge region) 5.40 14.1% 32.1%
South Staffs Water (South Staffordshire  region) 10.50 12.9% 33.3%

Note: The sector needs to meet a 50% leakage reduction by 2050 compared to a 2017-18 baseline. Over the 2020-25 period companies have committed to reducing leakage by 16%.

Storm overflow spills

  Average number of spills per overflow (based on total number of monitored spills and total number of storm overflows with spill data) Average number of spills per storm overflow (based on total number of monitored spills and total number of overflows) Percentage reduction in average number of spills per storm overflow, 2021 to 2029
Company 2021 2029
Anglian Water 25.60 16.63 35.0%
Dŵr Cymru 43.49 38.70 11.0%
Hafren Dyfrdwy 34.90 29.81 14.6%
Northumbrian Water 25.34 16.42 35.2%
Severn Trent Water 24.74 14.00 43.4%
South West Water 38.87 17.50 55.0%
Southern Water 20.23 15.45 23.6%
Thames Water 31.92 17.21 46.1%
United Utilities 41.80 19.60 53.1%
Wessex Water 22.45 21.13 5.9%
Yorkshire Water 33.57 25.37 24.4%
Sector 32.16 21.26 33.9%

Notes:

  1. Data for 2021 based on data reported to the Environment Agency and Natural Resources Wales; storm overflow performance is reported on a calendar year basis.
  2. We have compared the forecast position in 2029 to that of 2021 as rainfall for this year was similar to the longterm average.
  3. Hafren Dyfrdwy has informed us that it intends to revise the storm overflow figures in its PR24 business plan. We have therefore used its revised figure of 29.81 for 2029-30. This replaces the figure of 40.23 in the company’s PR24 business plan.
  4. For other companies numbers are based on those submitted in business plans on 2 October. Amendments have been made following initial checks by Ofwat.