Homes and businesses in Leeds City Centre stand to benefit from the new flood alleviation scheme which will make use of an Obermeyer moveable weir system which is designed to control water level in the river Aire as it passes through Leeds city centre.
The pneumatically-operated gates will replace fixed stone and masonry weirs at two locations in the city, Crown Point and Knostrop, and will allow water levels to be controlled during high flow events. This means the river can still be used by leisure craft and retain its aesthetic qualities without overflowing during peak rainfall. The gates, which are operated by compressed air and are designed to deflate when water levels rise, will be supplied by Dyrhoff Ltd, the Folkestone-based moveable weir specialists.
The gates chosen for the Leeds scheme are designed by the US company, Obermeyer Hydro. Dyrhoff has been the sole European agent for the Obermeyer gate system since 1996. The gates offer a number of unique benefits, including low maintenance and a low environmental impact, and are well suited to flood alleviation schemes. The Obermeyer gate system was developed in the USA in the late 1980s and Dyrhoff installed the first gates in Europe in 1997. To date Dyrhoff have supplied over 40 gates of this type in Europe, with fifteen being supplied at locations in the UK and France for navigation and flood control purposes in the last ten years, and a further twelve gates currently at the design stage for a major navigation and water level control project in Belgium.
The gates are operated pneumatically and provide automatic control of the upstream water level. They can be operated at any height from fully inflated to fully deflated. The patented system comprises a row of bottom-hinged steel gate panels supported on their downstream side by inflatable air bladders. By controlling the pressure in the air bladders, the upstream water level can be precisely adjusted within a specified control range and accurately maintained at user-selected set points.
A number of key parts, including the all-important steel gates, will be manufactured in the UK making this a flagship project for Folkestone-based Dyrhoff. The Leeds flood alleviation scheme and the gates are scheduled for completion in 2017.