Rainwater fees Severn Trent vs United Utilities

Chaoscontrol

I recently moved to Stockport from Solihull, and compared my water bills as I noticed a quite an increase. 

Here's the 6-month bill I got from Solihull, Severn Trent: https://i.imgur.com/XSdmXPi.png
Here's the 2-month bill from Stockport, United Utilites: https://i.imgur.com/e6SIgwt.png

The major thing of importance I noticed is rainwater. It jumped from roughly £50/year to £100/year. The house size is roughly the same (it was semi-detached, now it's end of terrace). 

• Rainwater charge doesn't seem related to water consumption, but a fixed charge.
• Manchester is known for being rainy, yes, but I don't think so much as double. 
• 2021 vs 2023. I could understand a certain increase, but again, not 100% increase.

How is this justified?

Another thing worth noting is that standing charge for waste water is £22/year in Severn Trent, while it's £4/year for United Utilities. Also can't understand this random difference, although it benefits me in this occasion. 

I also need to debug how we used 20m3 in 6 months back then to 12m3 in 2 months now. But that's for another day. 

I appreciate the discussion and insights. 

[Deleted User]

The major thing of importance I noticed is rainwater. It jumped from roughly £50/year to £100/year. The house size is roughly the same (it was semi-detached, now it's end of terrace). 

• Rainwater charge doesn't seem related to water consumption, but a fixed charge.
• Manchester is known for being rainy, yes, but I don't think so much as double. 
• 2021 vs 2023. I could understand a certain increase, but again, not 100% increase.

How is this justified?

Different parts of the country and individual water companies lead to different cost models . It has always been the case.

OFWat has oversight of the charges that utility companies set:

https://www.ofwat.gov.uk/regulated-companies/company-obligations/ofwat-regulating-the-industry-compliance-requirements-charging/