Maida Vale Flood Alleviation Scheme

Underground tanks that reduces the risk of flooding to houses in West London

West London, UK

Introduction

The Maida Vale Flood Alleviation Scheme was a project that has eliminated sewer flooding to almost 200 properties. The project was undertook on behalf of Thames Water by Optimise, a joint venture in which MWH, now part of Stantec, was the design partner and worked alongside contractors Murphy, Barhale and Clancy Docwra.

Scope

The Maida Vale area was served by three ’Bazalgette’ sewers all about 2m diameter and built in the late 19th century. However, these sewers did not have the capacity to transfer additional flows brought about by increased permeable areas and changes in climate. This resulted in extensive flooding to properties in the surrounding urban areas during severe storm events. Due to the sheer density of the urban area and the limited available space to build, part of the solution required flows to drop 13m into a tunnel and storage facility. To achieve this, a vortex type control structure was required to ensure flow could be safely and efficiently dropped to a low level.

Maida Vale

Challenges

A demanding timescale was a vital consideration for MWH. Key tasks were run in parallel, including the problem understanding, hydraulic modelling and detailed design. This ensured that MWH and its Optimise partners had sufficient time to undertake the construction. As all construction work was carried out within an extremely busy urban environment, risk to the general public was given great consideration and noise impact was kept to a minimum.

Solutions

The solution required separation of the flooding area from the sewer network. This was achieved by transferring flows to a 20m diameter, 26m deep storage shaft which pumps stormflows back into to the receiving sewers, when conditions allow. This has also been achieved through extensive hydraulic modelling to aid the development of a means of allowing the base / foul flow to remain connected to the existing sewer network, whilst ensuring that there is no risk of storm flows from the existing system causing flooding.

The Maida Vale Flood Alleviation Scheme was awarded the Keep the Public Fully Informed (Communication) Award by the National Joint Utilities group.

Images accredited to Thames Water.

Maida Vale