Elliptical concrete pipes solve surface water flooding problems
(17/05/2010)

With localised surface water flooding continuing to be a major problem, elliptical concrete pipes are now a far more effective and economic alternative to drainage systems such as box culverts – according to Stanton Bonna.

“The elliptical system offers significant advantages over others, particularly box culverts, because it provides a far superior hydraulic performance and a fully watertight elastomeric captive gasket joint”, explains Richard Whitmore from Stanton Bonna.

He added: “Despite the efforts of the Environment Agency, the UK is still faced with ground, rivers and drains that just cannot cope with heavy rainfall. Urban areas without open ground to absorb serious rainfall events are particularly prone, and have very little warning. A significant benefit for specifiers is that where pipes are laid in either the vertical or horizontal plane, the elliptical profile permits self-cleansing velocities at low flow rates. Consequently the risk of siltation is greatly reduced compared to the equivalent box culvert”.

Whitmore agrees that the draft Flood and Water Management Bill, published in April 2009, brings some clarity to surface water management, especially in its call to local authorities to produce local flood risk management plans - covering flooding from surface water, groundwater and ordinary watercourses. However, he believes that high water tables and shallow gradients are best served by elliptical pipes because they have far fewer joints than box culverts and do not require priming or sealing with a separate sealing compound.

He added: “Companies such as Arup and Dwr Cymru Welsh Water have already recognised the benefits that elliptical concrete pipes, but as climate patterns continue to change, there needs to be a faster uptake to this more viable solution to the ever increasing problem of flooding”.