Earlier this week, councillors at the Transport and Sustainability committee were updated on a new approach to cleaning gullies that will help reduce the risk of flooding in high-risk areas of the city.
Gullies near properties that have historically been affected by surface water flooding are now being prioritised and cleansed twice a year compared to every 18 months under the previous regime.
Others will be cleansed every 1, 2 or 4 years based on the potential risk at each location and historic silt data. Unfortunately, it’s simply not possible to clean all the gullies all of the time.
The new regime, which is based on data collected over many years, means we’ll be able to tackle the high-risk areas in line with the available budget.
Practical and affordable solutions
Councillor Trevor Muten, Chair of the Transport and Sustainability committee said: “Surface water flooding is a growing problem across Brighton & Hove, and we have to find practical and affordable solutions to tackle it.
“Surface water flooding is caused by the sewer system being overwhelmed and there are a lot of reasons for that, including the ongoing and increasing threat posed by climate change.
“As a council, we need to do what we can by ensuring gullies in high-risk areas are kept clear and I believe this change of approach will do just that.
“But we must also work with Southern Water, who manage the city’s sewer system, and urge them to do more to prevent and reduce the risks of flooding, including the construction of more sustainable drainage systems.”
There are 22,782 gullies and 4971 soakaways that drain surface water from the roads and pavements in Brighton & Hove.
Most of the water runs into a sewage system which is managed by Southern Water. At times, this system is unable to cope with heavy rain and flash flooding.
Connecting new gullies or replacing them with larger gullies could overload the system and risk sewage discharging onto our streets during heavy rainfall.
The causes of flooding
There are several different factors which can lead to surface water flooding in the city.
Sewage system capacity
During extreme weather, Southern Water’s system is unable to cope with the sheer volume of water, regardless of the condition of our drains and gullies. Replacing this Victorian system across the city would be extremely expensive.
Climate change has led to an increase in the number and intensity of extreme rainfall events. An average gully is designed to accommodate rainfall of 5mm per hour. During one event in January, we experienced rainfall of 30mm per hour.
Leaves and debris are removed from gullies as part of the council’s cleansing service. We have 61 priority sites based on years of historic flooding data. Unfortunately we can’tclear all the gullies all year round.
More and more people are building driveways in front of their houses or laying non-permeable surfaces. This means the water has nowhere to go, other than into the sewage system. However, all new applications are required to ensure that no water will discharge onto the public highway.
Construction / food waste
In recent years, there’s been an increase in construction waste, particularly cement, being dumped into the sewage system. This can block the system and be expensive to repair. The same happens when businesses dump cooking fat into the system.
Residents can report a blocked drain or gully on our website.