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.

A further update was published on 22 October 2024. This enables comparison between the expenditure request submitted in the final version of each company’s business plan (March 2024), our proposed allowances in the draft determinations (July 2024) and the revised figure requested by each company in their PR24 consultation responses (August 2024).  PR24 data update.

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Customer bills

Water and wastewater companies

Actual average bill Average bill proposed in company business plan Average bill proposed in Ofwat’s draft determinations Company representation proposed average bill  Representation bill increase compared with 2024-25
Water and wastewater companies 2024-25 2029-30 2029-30 2029-30 2029-30 vs 2024-25
Anglian Water 491 573 557 614 25%
Dŵr Cymru 455 602 603 626 38%
Hafren Dyfrdwy 392 560 524 568 45%
Northumbrian Water 415 471 460 501 21%
Severn Trent Water 398 546 496 580 46%
Southern Water 420 727 603 772 84%
South West Water 497 596 561 613 23%
Thames Water 436 627 535 667 53%
United Utilities 442 554 536 584 32%
Wessex Water 508 690 497 658 29%
Yorkshire Water 430 569 537 583 35%
Weighted average bill 439 585 535 615 40%

Water only companies

Actual average bill Average bill proposed in company business plan Average bill proposed in Ofwat’s draft determinations Proposed average bill in representation Representation increase in company bill from 2024/25
Water only  companies 2024-25 2029-30 2029-30 vs 2024-25 2029-30 2029-30 vs 2024-25
Affinity Water 192 217 203 240 25%
Portsmouth Water 111 135 135 143 29%
South East Water 232 281 248 305 32%
South Staffs Water 161 181 183 181 13%
SES Water 221 274 187 238 8%
Weighted average bill 192 224 204 237 24%
  1. Some companies have restated their 2024-25 bill figures resulting in a change from previously published figures.
  2. Dŵr Cymru have changed the treatment of social tariffs in their bill presentation. Their 2024/25 actual figures and 2029/30 representation figure now include the impact on average bills of the company’s contribution to social tariffs.
  3. Southern’s representation includes the impact on bills of costs within the delivery mechanism.
  4. Companies have adopted different approaches to the treatment of the allowed return to investors in their representations. Some have stated customer bills based on the allowed return included in our draft determinations while suggesting that the allowed return should be higher. Others have proposed a higher allowed return and included this in their calculations.
  5. The bills shown for each water-only company do not include the cost of wastewater services. These are provided by the water and wastewater company which serves its area.

 

Expenditure allowances

Water company PR24 Business Plan proposals – net total expenditure (£m, 2022-23 prices) PR24 draft determination allowances (£m, 2022-23 prices) PR24 company representations on draft determinations (£m, 2022-23 prices)
Change from business plan proposals to DD representations
Anglian Water 9,522 9074 10407 9.3%
Dŵr Cymru 5,627 4978 5917 5.1%
Hafren Dyfrdwy 256 221 262 2.2%
Northumbrian Water 6,020 5608 6294 4.6%
Severn Trent Water 13,316 11282 14639 9.9%
South West Water (inc. Bournemouth and Bristol) 4,469 4098 4585 2.6%
Southern Water 7,172 6715 9381 30.8%
Thames Water 21,403 16312 23719 10.8%
United Utilities 13,831 11414 13671 -1.2%
Wessex Water 5,416 3622 4984 -8.0%
Yorkshire Water 7,682 7123 8019 4.4%
Affinity Water 2,127 1828 2323 9.2%
Portsmouth Water 346 401 361 4.4%
South East Water 1,889 1278 1954 3.4%
South Staffs Water 817 785 806 -1.3%
SES Water 413 329 414 0.1%
Industry total 100,305 85068 107736 7.4%

The figures shown are: after the application of frontier shift efficiency (the rate of efficiency improvements that even the most efficient companies in the industry can achieve); real price effects (prices faced by water companies increasing or decreasing, relative to general inflation); and after the deduction of developer services revenue (received from developers to connect new houses to the water and wastewater network).

 

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.