England renews its water mains once every 700 years.

England's water companies replaced their mains at 0.14% a year. At that rate, the network is renewed once every 700 years. The National Audit Office published the rate. The pipes it describes run under every street in the country.

What the companies measure

Every storm overflow in England now has a monitor. In 2025 the 14,303 overflows in the Environment Agency's return spilled 292,119 times, or 20.5 times each, down from 31.8 in 2024. The return records how long each overflow spilled. It does not record how much went into the river, or what was in it.

Reservoirs are watched weekly. In the week ending 6 October 2026, storage across England stood at 54%, 21% below the average for the time of year.

What they do not

The Drinking Water Inspectorate found 233 service reservoirs and tanks in England that had not been inspected for over 10 years, 3.1% of the total. Pollution incidents rose 27% from 2019-20 to 2024-25, against a committed 30% cut. Ofwat plans to start collecting condition data for the most important above-ground assets in time for the next price review.

Why it matters now

Ofwat's final determination allows £104bn of spending from 2025 to 2030, including £11.3bn for 2,884 storm overflow improvements. Spending on that scale needs a record of what each asset is, where it is and what state it is in. Today that record sits in separate returns, reports and company systems.

Savitram joins the returns, the rivers and the companies into one record per overflow and reservoir, with the source and date on every line.