Park Road Reservoir Update

On 23 February I was fortunate enough to join a visit by the Institute of Civil Engineers to the Park Road reservoir. The visit commenced with a presentation at the Reg Driver Centre in Christchurch Park. It provided an insight into the challenges presented by a project of this nature. Then off to Park Road where site manager Neil Davidson was our host.

The project commenced on site in the autumn of 2011 with a planned duration of about six months. Not unusually one or two issues arose which will now see work continue till June this year. Firstly the removal of 6,000 tons of topsoil from the concrete roof of the reservoir took longer. Surveys identified that the risk of deploying heavy equipment on the roof was not an option. Much of the work had to be carried out by hand with shovels and wheelbarrows, with final removal via a vacuum pump. Secondly, a decision has been taken to build a new internal partition wall effectively dividing the reservoir in two, an additional investment that will ensure future planned maintenance will be possible without the need to drain the entire reservoir. That has added £900k to the capital costs which will now total about £2.4 million!

As John Norman explained in last October's Newsletter. the reservoir was built in 1902 and has a capacity of 21 million litres of fresh water to serve the north of Ipswich with water pumped into the reservoir from a borehole in nearby Whitton. It is a credit to the original engineers that the internal cast iron support columns and steel beams have survived in good condition and remain suitable for shot blast cleaning and epoxy coating. The concrete floor and roof are being checked carefully for damage and any cracking identified is being over-banded with a flexible product. All products used inside the reservoir have to be certified as suitable to come into contact with drinking water. Pipe-work has been modified to improve the flow of water into and through the reservoir.

This is a significant project and the site is subject to stringent safety management procedures. On the day of our visit 45 people were signed in to work on the site. Like everyone on site we were expected to arrive with suitable personal protective equipment including safety boots, gloves, helmets, goggles and fluorescent jacket. We were fortunate enough to be allowed, under careful supervision, to descend on to the reservoir floor. Full access was not possible as some areas are designated as confined spaces with all the safety controls in place that necessitates. It is an amazing space down there and it was a privilege to observe the skilful and labour intensive work being carried out - grateful thanks to our busy hosts.

All those working on the site consider themselves fortunate to be involved with this unique project but they are also acutely aware that there is inevitably some disruption to local residents from traffic movements (500 12-tonne lorry movements for the removed topsoil alone) and site noise. The site operates between 8 am and 5.30 pm each weekday with the noisiest element now complete (removal of topsoil). Hopefully the project will complete on time and ensure it is another 100 years before this level of refurbishment is necessary.

Once the work is complete the reservoir will be deep cleaned and disinfected before refilling and water testing commences. The roof will receive a waterproof membrane and be protected with a layer of stone chippings rather than reinstating the topsoil.

Graham Smith