Scottish Water records 4x more overflows because of 4.5x more monitoring

(by Karma Loveday)

Scottish Water has expanded the number of monitored combined sewer overflows from 6% to 30%.

According to its 2025 data release, over 1,000 new monitors were in action last year, taking the total to 1,287. Inevitably, this resulted in a higher number of recorded overflow events: with over 4.5 times more data locations available, the results showed four times as many overflow events occurring, but less than double the duration of events.

The additional monitors form part of Scottish Water's £500m Improving Urban Waters programme, which is increasing monitoring and transparency, and supporting action to improve the water environment. More than 2,000 locations are now shown on Scottish Water's near real-time overflow map. The company will continue adding monitors to the map, and plans to publish annual 2026 overflow event data for all locations shown on the map in March 2027.