What is a stormwater overflow?

An event where excess water which is at risk of overwhelming the sewage system during periods of rain is released into the water environment to prevent both flooding and excess water backing up into homes and business. The releases are typically heavily diluted with rainwater and in most cases are consented releases permitted by the Environment Agency.

What are storm overflows? (southernwater.co.uk) 

Role of Fareham Borough Council

The Council is increasingly aware of a number of incidents relating to stormwater overflows being released into the bathing waters of the Solent and are also aware of the impacts of these stormwater releases on the marine environment, communities and local businesses.

The Council is unable to direct Southern Water to make investments and improvements in its wastewater network to deal with stormwater releases and it cannot use any enforcement measures if Southern Water fail to comply with its environmental permit. The role of enforcement is carried out by the Environment Agency.

Despite this, the Council raises the issue of stormwater releases with Southern Water through responding to their business and Drainage Wastewater Management Plans , which are long-term plans – spanning 25 years or more – that set out the investments needed to make wastewater and drainage systems fit for today and the future and through the Council's partnership working with the Partnership for South Hampshire. The Council uses these opportunities to raise the wider issues of climate change (which could lead to increases in storm overflows and flooding), population growth (which could lead to increased burden on existing infrastructure) and aging assets and infrastructure as important challenges Southern Water need to address and invest in.

Role & priorities of Southern Water within the East Hampshire Catchment

• Reducing the number of spills from the 93 storm overflows which together currently spill around 1200 times per annum
• Separating or attenuating excess rainwater in the sewer networks to reduce the risks of flooding and frequency of storm overflow discharges, especially in Southsea, Bursledon, Denmead and Eastney
• Investigating the potential impact of wastewater discharges on Good Ecological Status in designated Habitats including the Solent and Langstone Harbours
• Implementing measures to reduce nutrients in discharges at Budds Farm WTW
• Planning for potential significant developments at Portsmouth, Fareham, Tipner West, North Whiteley and Waterlooville
• Improving the resilience of our networks and treatment works to prevent pollution incidents, particularly in Gosport, Fareham, Burseldon, Drayton and Waterlooville
• Reducing the risk of sewer blockages by increasing sewer jetting and targeting customer campaigns to reduce the amount of FOG (fats, oils and grease) and unflushables in the sewer network around Havant
• Reducing the risk to groundwater by reducing leakage from our sewers in the Havant, Horndean and Waterlooville areas.

Southern Water have a Storm Overflow Task Force  who are a dedicated team responsible for driving Southern Water's ambitious targets to significantly reduce storm overflows by 2030. The team are piloting schemes across the region, building long-term cross-industry partnerships, and developing a regional plan to ensure we have a sustainable system fit for the future.

Role of The Environment Agency

The Environment Agency  are the environmental regulators for Wastewater undertakers such as Southern Water. It is the Environment Agency's responsibility to ensure Southern Water comply with environmental permits and monitor impacts from Southern Water's activities. Where Southern Water fail to comply with environmental permits, it is the Environment Agency who is responsible for taking necessary action.

Ensuring Southern Water's infrastructure can cope with development set out in the Adopted Fareham Local Plan 2037.

Southern Water were consulted at each stage during the production of the Fareham Local Plan. They initially raised concerns about the ability of parts the sewer network to accommodate the development being proposed for some of the emerging housing allocations in the Plan. This was principally in relation to the limited capacity of the sewer network in that area to accommodate additional sewage and improvements will be necessary to reduce the risk of sewer flooding. Southern Water requested that the Council's Development Management team consult them on any future planning applications in those areas where there is limited capacity in the sewage network. These actions were agreed by the Council and Southern Water in a signed Statement of Common Ground. This can be viewed here (231 KB).

Concerns were not raised by Southern Water through the Local Plan process as to the ability of their wastewater treatment works to accommodate the scale of development being proposed through the Local Plan.

Useful Links

Southern Water have a dedicated website which displays near real-time storm release activity information relating to our coastal bathing waters. Beachbuoy (southernwater.co.uk) 
Should residents wish to raise their individual concerns about the impact of stormwater overflows on the marine environment they should to southern water here.