Winchester & Farnborough Drainage

Avon Construction worked with South West trains to improve the drainage in the station carparks at Winchester and Farnborough.

Rainwater falling on the top deck of the carparks was draining down rain water pipes and discharged onto the lower deck. The design and build work Avon Construction did connected these rain water pipes into drainage systems to remove the water from the carpark lower decks and relieve flooding.

The work at Winchester fed the rain water into two 80m soakaways that were constructed underneath the lower deck. At Farnborough Station, we connected the 48 downpipes from the carpark upper deck to a large drainage and attenuation system consisting of 350m of 600mm diameter pipes and 9 manholes. This drainage and attenuation system then connects into the local Surface Water Sewer through a Hydrobrake limiting the maximum flow into the sewer.

All construction was carried out in the station carparks while the carparks remained open, reducing disruption to passengers and carpark users. The work was further restricted working under the upper deck where the available headroom varied between 2 and 2.4m. The project was successfully delivered with minimal disruption to the station users.