The number of discharges into watercourses in Yorkshire decreased by 24.5% in 2025 when compared to the previous 12 months.
Discharges fell from 68,164 to 51,404 and the duration of the discharges into watercourses fell from 430,263 hours to 285,230 hours – a decrease of 33.7%. The average number of discharges per storm overflow also decreased from 31.4 in 2024 to 23.6 in 2025.
The decrease in 2025 follows a 12% reduction in discharges in 2024.
Richard Stuart, director of asset delivery and engineering at Yorkshire Water said:
“A reduction in the number and duration of discharges across the region in 2025 is a positive. The dry weather in 2025 contributed to the reduction, but we also saw above average rainfall in the region in January, September, November and December. Our £180m investment over the last two years targeted over 100 storm overflows and is delivering a reduction in storm overflows across the region.
“Some of the work as part of this investment was completed in early 2025, so we are yet to see the full benefit during an entire 12-month period, but we are seeing the investment beginning to make an impact. Of course, there is more to do and we’re underway with a further £1.5bn investment to continue tackling the performance of storm overflows.
“We know we need to continue driving down the number of discharges to our rivers and seas and we’re committed to delivering those improvements over the next few years and beyond. By April 2030 we will invest £1.5bn to upgrade and improve more than 450 storm overflows, tackling those discharging the most frequently, for the longest time and those that have a significant impact on the receiving watercourse.”
Wastewater treatment works in Scarborough and Bridlington are among those that will receive investment by April 2030.
