Hundreds of underground tanks are being built that can store up to 300,000 litres of waste water to prevent it entering water courses after heavy rainfall.
The government has set a target for each storm overflow, also known as a Combined Sewer Overflow (CSO), to operate on no more than 10 occasions annually.
Many in Yorkshire currently operate about 40 times a year.
Jon Stokes, from Yorkshire Water, said: “The tanks are sized so that we can make sure they don’t spill more than 10 times a year, that will have a very minimal impact on water quality, there will be a mixture of run-off from roads and roofs, mixed with the foul sewage from people homes.”
Yorkshire Water said that reducing the number of spills below 10 would involve billions of pounds additional funding and a complete re-plumbing of the sewer network.