Sustainable Drainage Systems (SuDS)

Pilot schemes introducing Sustainable Drainage Systems (SuDS) within the highway are being launched in Fareham.

Phase 2A - Southampton Road and Harrison Primary School

Main works to install a new drainage system including below ground attenuation feature completed during summer 2026.
From 28-30 October, resurfacing work will be completed within the school driveway. Permitted working hours will be between 7:30am and 5:30pm Monday to Friday, (no noisy works before 8am).

Traffic Management

The school driveway will be closed while the works are underway.
Access to some properties and driveways may be restricted at times. The site team will work with residents to maintain access wherever it is safe and practical to do so.
A temporary suspension of on-street parking will be required near the school driveway to keep vehicles away from the work area, allow access for construction vehicles, and enable the works to be completed safely and efficiently.

Phase 2c – Serpentine Road (Trial)

Works are scheduled to take place from 26 to 30 October 2026. Temporary two-way traffic lights will be in place for the duration of the works. Permitted working hours will be between 7:30am and 5.00pm, with no noisy works before 8:00am. Some temporary on-street parking suspensions will be required to facilitate the works access.
The works involve the installation of two temporary road-narrowing features, to trial the layout of planned future raingardens. The temporary installation will allow us to assess how the planned future layout would operate in practice and will help inform the design development of the proposed permanent raingardens.
The changes are being implemented under an Experimental Traffic Regulation Order (ETRO). During the trial period, Hampshire County Council will monitor the impact of the changes on traffic movements, parking and access to residential driveways. Feedback from residents and road users is encouraged and will play an important role in informing future decisions. Please see signage on-site and get in touch via Contact Us section.

View the artist's impressions of the permanent raingardens which would be built if the trial is successful.

Hampshire County Council is working in partnership with Southern Water to deliver Sustainable Drainage Systems (SuDS) improvements in Fareham as part of a wider programme aimed at reducing sewer flooding and protecting local rivers and coastal waters.

Older combined sewers in the UK carry both household wastewater and rainwater in the same pipes. During heavy rainfall, large volumes of rainwater from roads, driveways and roofs enter the combined sewer network and these systems can quickly become overloaded. This increases the risk of waste water being released into rivers and the sea through combined sewer overflows (CSOs), to prevent flooding to homes and businesses.

Southern Water holds responsibility for managing waste water across the majority of Hampshire and it has a legal requirement to reduce CSO releases. Highway SuDS are a key part of Southern Water’s long term plan to reduce storm overflow releases by managing surface water more sustainably, alongside sewer upgrades and other improvements across the region. By capturing, slowing, and managing rainwater close to where it falls, the scheme will reduce pressure on the sewer network, decrease CSO events and improve environmental outcomes.
Hampshire County Council is working with Southern Water to reduce the amount of rainwater entering combined sewers from roads, homes, and other hard surfaces. This pilot introduces Sustainable Drainage Systems (SuDS) within public highways to support that goal. Fareham is a priority catchment for action under national environmental targets.
The pilot project will test feasibility, effectiveness, and delivery processes, informing a broader strategy for future SuDS schemes across Hampshire.

Please read the FAQs MS (Sway document).

By slowing and managing rainwater from the highway and adjoining paved areas before it enters the sewer network, we can reduce CSO events and improve environmental outcomes. SuDS manage rainwater in a more natural and sustainable way by:

Temporarily storing water close to where it falls
Allowing gradual infiltration into the ground and evapotranspiration into the air
Slowing the flow into sewer systems

Benefits for the community and environment:

Lower risk of sewer flooding during heavy rainfall
Cleaner rivers and coastal waters
Reduced pollution entering the environment
Nature based drainage solutions that support biodiversity
More resilient infrastructure for future climate conditions

This partnership with Southern Water is a unique opportunity to deliver solutions that benefit both the environment and the local community. Please see further information from Southern Water is provided below:

More information on SuDS can be found at Southern Water’s website: Sustainable drainage solutions.

Phase 1: Westborn Road, Fareham

This phase of the pilot delivered SuDS features within the highway at Westborn Road, Fareham, including above ground raingardens, new below-ground highway drainage features, and underground water storage.

These SuDS features will:

Capture and temporarily store rainwater close to where it falls
Slow the flow of water into sewer systems
Reduce pressure on the wider drainage network during storms.

Please view the technical plans:

Delivery of the Phase 1 Pilot Scheme was formally approved under delegated authority by the Director of the County Council’s Universal Services directorate on 26 September 2025. Please read the Decision Report . The associated changes to on-street parking were formalised. Please read the Decision Report.

Works to construct this phase of the project completed during summer 2026. View the visuals of the ground raingardens.

Phase 2a: Harrison Primary School and Southampton Road

These works will allow the disconnection of existing road drains in Southampton Road from the sewer system that currently carries both rainwater and wastewater. Rainwater from the road and nearby driveways will instead be directed into a separate rainwater sewer beneath the school site.
A new below ground water attenuation system has been constructed beneath the school driveway, which will hold water during heavy rainfall and release it slowly into the sewer network. This will reduce pressure on the drainage network and lower the risk of it becoming overloaded during intense storms.

Please view the technical plans:

General arrangement drawing.
Drainage layout drawing.

Works to construct the drainage elements of this phase of the project completed during summer 2026, with final resurfacing of the school access road planned for October 2026.

Phase 2b: Southampton Road and Serpentine Road

This phase of the project is in development and will install raingardens (kerbed carriageway build-outs with above ground planting and below ground water storage system) on Southampton Road and Serpentine Road, close to their junctions with the A32.
The raingardens will be installed in areas where parking is already restricted by double yellow lines and are therefore not expected to significantly affect on-street parking. Works are expected to begin in early 2027.

Please see the technical plan.

Delivery of the Phase 2b Pilot Scheme was formally approved under delegated authority by the Director of the County Council’s Universal Services directorate on 7 August 2026. Please read the Decision Report.

Phase 2c: Serpentine Road

This phase of the project would see the installation of two new raingardens on Serpentine Road between its junction with Harrison Road and the A32. The raingardens would include underground water storage and would be created by extending sections of the kerb into the road. Their location would also help to slow traffic and improve road safety.

The proposals are subject to a trial period, during which time the impact on resident access and traffic movements to be monitored and assessed. The findings from the trial will help inform decisions on any permanent installation. Any permanent installation, subject to the outcome of the trial and further approvals, would be carried out in 2027.
Please see the proposed layout plan of the trial arrangement.

Southern Water is funding the design, construction, and maintenance of the SuDS features in this pilot. The project will test feasibility, effectiveness, and delivery processes, informing a broader strategy for future SuDS schemes across Hampshire.

Visit Causeway One.Network which is where the planned works are published and is an independent platform that allows real-time monitoring of all the UK’s roadworks and diversions.

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Name Highways, Engineering and Transport
Email [email protected]
Phone 0300 555 1388

Address
Universal Services
Hampshire County Council
The Castle
Winchester
SO23 8UD