Water bills in Scotland will increase by almost 10% from April.

Scottish Water said the 9.9% rise was necessary to invest in infrastructure to cope with periods of “drought and intense rainfall” brought on by climate change.

It means homes in the lowest council tax band A will be charged more than £400 for their supply and waste water collection for the first time.

The body also said the increase, which follows an 8.8% rise last year and a 5% rise in 2023, would “rebalance charges” which were held back to help households after the Covid pandemic and cost of living crisis.

Scottish Water said it served more than 2.6 million households and 225,000 businesses across the country.

Domestic water bills are collected along with council tax in Scotland and are tied to the eight bands used to determine their value.

In band A, the lowest valuation, yearly charges will increase by about £36, while in band H, the highest, they will rise by £108 to £1,200.78.

Homes categorised in band D will face a £54 annual rise.

Scottish Water said current projections showed a four-fold increase in Scotland’s daily water supply deficit during droughts or periods of low rainfall.

It said the country could face a deficit of up to 240 million litres a day, up from 60 million litres, while water main bursts are expected to become more prevalent by 2050 due to drier ground conditions creating movement.

Chief executive Alex Plant said its infrastructure was under “serious pressure” due to the changing climate.

A report by the Scottish Environment Protection Agency (Sepa) for autumn last year said Scotland had experienced “drier than normal conditions” which had “impacted water resources” across the country.

Met Office rainfall data showed autumn 2024 was the fifth driest in 100 years.

That followed a summer which was the wettest on record for parts of the country.

A new report covering the winter period will be released later this year.

Mr Plant said a lack of “increased investment” in the wake of environmental challenges risked “reductions in service quality”.

He said: “People in Scotland are rightly proud of our water and maintaining our high standards means we need long-term sustainable investment.

“We’ve all seen – including in the last few days – how weather conditions in Scotland are becoming more extreme, and we are seeing more frequent periods of both drought and intense rainfall.

“This puts our current infrastructure under significant pressure, and, without increased investment, we risk reductions in service quality in the future.

Mr Plant added: “This announcement will enable us to continue to provide essential high-quality services to millions of people today, while also investing prudently for the future, and ensuring that costs are shared fairly between current and future generations.”

The maximum amount that can be charged by Scottish Water for the 2021-7 period is set out by the regulator, Wics. The annual increase is then set by the board of Scottish Water.