Utilities will need to up their investment in replacing pipework and treatment plants as climate change increases pressure on the water infrastructure, engineers have warned.

A new report from the Institution of Mechanical Engineers (IME), published today (7 August), predicts that Britain’s water industry faces higher costs for treating and managing water supplies due to the increasing risk of drought and flood.

The report, entitled “Water: Drought and Flood”, says companies will need to “significantly” increase the pace of pipework replacement, which while expensive is “becoming essential”.

It says that water treatment plants will be required to run at peak flow rates for longer in the summers of the future, raising maintenance and running costs.

Constantly operating plants at peak flow will increase the energy required for running equipment, such as pumps and compressors, and cause parts to wear out faster, according to the report.

The increased demand means the plants will also require more chemicals to clean the water faster.

It says that to combat flooding, particularly after long periods of dry and hot weather, greater investment will be required in urban drainage systems. This will include more investment in sustainable urban drainage, such as parkland, ponds and ditches.

The report recommends that all major UK cities should publish research on their water infrastructure needs to ensure new homes and businesses are designed and developed with increased extreme weather in mind.

Including sustainable urban drainage and grey water recycling in new-build properties will reduce the burden on treatment works in the summer and help to manage extreme rainfall events.

The report also recommends a public awareness campaign on the value of water and the consequences of the changing climate.

It urges the industry, with the support of Water UK and the National Infrastructure Commission, to draw up a water infrastructure sustainability plan that factors in the consequences of the increased risk of drought and flood.

Dr Jenifer Baxter, head of engineering at the IME and the report’s lead author, said: “We need to make people aware of the value of water as a resource. Consumers need to understand the challenges of managing water in more extreme environments and the increased costs that water companies will face running treatment plants at higher flow rates as well as reducing leakage.”

Responding to the report, Tony Smith, chief executive of the Consumer Council for Water, said: “The hot summer has exposed some of the vulnerabilities of our water and sewerage network and those pressures will only intensify in the face of our changing climate and growing population.”

“Water companies need to strike the right balance between tackling the needs of current and future generations through a more resilient network, while providing stable bills in the longer term. These challenges are not insurmountable if water companies are willing to embrace innovative ideas rather than relying on more traditional approaches.”

A spokesperson for Water UK added: “This report is likely to be a useful addition to the debate about the future of water, and we will read it with interest.

“The water sector’s own ground-breaking research in 2016 set out some of the growing risks to water services due to climate change and population growth.

“Water companies have invested heavily over the past three decades to improve services and continue to invest £8 billion each year, and we need to sustain that and encourage much more efficient use of water.

“Companies will be publishing plans for managing water resources and drainage in September in order to address the pressures that we all face from climate change and population growth.”