More than 2,500 restaurants and food businesses have installed fat traps in the past year.
The change follows outreach efforts by Thames Water to tackle sewer blockages caused by fats, oils and grease (FOG).
The outreach programme focused on the Thames Valley area , where FOG remains a major contributor to fatbergs.
Tessa Fayers, director of waste and bioresources at Thames Water, said: "Fats, oils and grease are one of the biggest causes of sewer blockages across our region, yet they're also one of the most preventable.
"Every year, thousands of blockages are caused by FOG entering the sewer network, putting homes, businesses and the environment at risk.
"Our Network Protection teams work closely with food businesses to provide advice, guidance and practical support to help them manage grease responsibly and meet their obligations.
"The vast majority of businesses want to do the right thing, and we are pleased to see thousands installing grease management equipment as a result of this engagement.
"However, where businesses repeatedly ignore advice and fail to take action, we will not hesitate to pursue enforcement action.
"Protecting our sewer network and preventing pollution is essential, and we expect all food businesses to play their part."
FOG causes more than 20,000 sewer blockages each year in the region and costs around £40 million annually to clear.
These blockages are responsible for more than 60 per cent of sewer flooding incidents.
Under the Water Industry Act 1991, it is a criminal offence to put substances such as fats, oils and grease into a sewer if they could cause blockages, damage the sewer network, or interfere with wastewater treatment.
In the past year alone, Thames Water’s network protection team conducted more than 19,000 visits to food businesses, offering education, support and practical advice.
The team promotes the use of fat traps, which are usually stainless-steel devices installed in commercial kitchens to capture FOG before it reaches the drains.
While many businesses comply, the team has found some deliberately bypassing equipment to avoid maintenance costs.
In one case, a takeaway business cut away part of a fat trap and fed a pipe directly through the unit, allowing FOG to enter the sewer system while appearing compliant from the outside.
Thames Water carries out repeat visits to ensure equipment is correctly installed and maintained.
Where businesses remain non-compliant, the company considers legal action.
In the past five years, Thames Water has prosecuted three businesses for improper trade effluent disposal and sewer misuse, resulting in fines and costs totalling over £50,000.
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