Ageing sewer network ‘ticking clock’ for flooding problems in Derbyshire

Flooding has hampered Matlock with increasing severity and frequency in recent years with residents now begrudgingly accepting the widespread disruption and worrying that the heavy rainfall can cause. The shock and surprise have dissipated – unlike the floodwaters.

The town faces flooding woes from two key sources: Water running off the steep surrounding hillsides, including the Wolds, and surging torrents rising up from the River Derwent.

Research from a Matlock resident and two of its district councillors, including its flood warden, has shown that sewage from hundreds of houses in the northern part of the town is being funnelled through a 22.5cm ageing pipe. Their research has also found that the existing pressure on the area’s sewer system is already causing significant problems.

This includes foul sewage flooding into the Presentation Sisters Care Home in Chesterfield Road on July 8 and 14.

Human waste was also strewn around the surrounding area as a result of the overloaded system, with young children reportedly being observed picking up the deposits believing it was mud.

Their research has found that more than 300 homes discharge waste into one pipe in the Presentation Avenue area. They fear that plans to build more houses in this area, including 423 on the Wolds itself, would exacerbate the current situation.

Their research found a key pinch point in the system between the care home and St Joseph’s Voluntary Academy – which also sits a few streets away from Highfields School.

This pinch point is caused by the “slackening” of the sloping system, which relies on gravity, and becomes less steep in the problem spot, with a slight hump.

They say the issues in the system were not present before the Treetops development, built by William Davis Homes in Asker Lane. This, they say, also led to flooding issues at Castle View Primary School.

In a joint letter to council officials, Cllr Steve Wain and Cllr Jo Linthwaite wrote: “The surcharging and backing up of the foul water in this area is totally unacceptable, and we request that you all meet urgently and discuss the way forward and provide a remedy for this unacceptable series of events.

“This regular surcharging and backing up of human waste is having a visible impact on human health and wellbeing. This is further exacerbated by the slackening of the slope as previously mentioned. On behalf of the residents of Matlock, Councillor Linthwaite and I urge you all to thoroughly examine the evidence provided, ensure that the issues are effectively remedied and provide a robust plan which will protect our communities.”

They write that Severn Trent Water has remained the local sewer network after reading through the research and being alerted to the issues and carried out a full CCTV survey – finding no blockages

The councillors concluded by dubbing the troubled sewer system “a ticking clock on the cyclical nature of flooding in Matlock with the wet months quickly approaching”.

Matlock has witnessed around half a dozen “one-in-100-year” flood events in the past 20 years, notably in 2019, 2020, 2021 and 2022.