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.

Canadian energy producer Boralex, whose core business is dedicated to renewable energy, commissioned their latest rubber dam at the Buckingham City power plant near Gatineau, Quebec. This is the second contract completed with Dyrhoff Ltd. The new rubber dam provides the 10MW power plant with a fully automated inflatable flashboard system, and follows on from the successful design and supply, also by Dyrhoff, of an inflatable flashboard system at Boralex’ 2MW East Angus hydro power plant in 2012.

Many hydroelectric plant operators using traditional, manually operated flashboard systems are now turning to this well proven technology as it requires a relatively low capital investment and can easily be adapted to existing structures.

The new technology offers dam owners the increased storage capacity needed to optimise hydroelectric generation, enabling operators to increase or decrease the effective height of the dam remotely and safely.

Another key attribute of inflatable rubber dams is their minimal impact on the environment. They use no lubricants, have practically no moving parts and do not require painting, keeping maintenance to a minimum.

Dyrhoff’s engineers are currently overseeing the installation of rubber dams on two projects in the Americas. Both projects are replacements of Bridgestone rubber dams which were originally installed in the 1980s and 1990s. In USA, Rob Pace is advising on the installation of a seven-span hydropower rubber dam on the Missouri River in Montana. In Guatemala, Kenan Tezcan and Martin Bilafer are advising on the installation of a Sumitomo-manufactured rubber sheet at a hydro plant in Zunil Province. This dam has been subject to high levels of sedimentation and will incorporate Dyrhoff’s innovative replaceable cover sheet technology to protect against abrasion (Patent Pending No. GB1400246).  

Installation of rubber dam in Guatemala

Following a record number of enquiries in 2013, Dyrhoff has had an equally strong start to 2014, with seven projects awarded in January and February.

In Canada, we are pleased to be working again with Boralex for their Buckingham City hydropower project. Dyrhoff previously designed and supplied a 3-span rubber dam for Boralex in East Angus, Quebec (see picture). Dyrhoff is working on a design for a 2-span air-inflated dam at Buckingham City, with installation due this summer.

In USA, we have concluded the design and approval process with the consulting engineers for the Hubbell Southfield combined sewer outlet. Dyrhoff will be supplying dams to help control storm water outflows into the Rouge River. This will be the first project in which Dyrhoff uses European-manufactured rubber sheeting, following an agreement reached with an established EU supplier last year.

In Europe, Dyrhoff has secured several new contracts for supply of Obermeyer spillway gates. We are excited to have been selected as supplier for Latvia’s Aiviekste hydropower plant which will be the first use of pneumatic gates of this type in the country. We are working with local civil contractor TILTS Ltd on the project, which is being delivered for the state-owned electricity supplier, Latvenergo. Elsewhere, we will be adding to the portfolio of Italian small hydropower plants using Obermeyer gates with new projects in Tuscany and Emilia-Romagna. In Bulgaria, we are in the design phase of a project to supply a gate for a privately-owned hydropower plant in the Plovdiv Province. Finally, our Norwegian office is arranging design and supply of a gate for a hydropower project in Buskerud County.

Dyrhoff is very much looking forward to working with our customers on these projects.

La technologie des barrages gonflables Dyrhoff a récemment été le sujet d’un article du New York Times. Cet article a suivi l’installation de deux barrages gonflables destinés au contrôle des eaux de pluie dans les égouts de la ville. L’article de deux pages a été publié dans la rubrique Infrastructure du journal et décrit comment les barrages protègent les rivières de la ‘Grosse Pomme’ de la pollution. Lisez l’article ici:

http://www.nytimes.com/2012/09/16/nyregion/in-bowels-of-new-york-city-inflatable-dams-help-block-wastewater-overflow.html?ref=nyregion

Dyrhoff’s rubber dam technology was recently showcased in an article in the New York Times. The article followed the installation of two rubber dams for storm water control in Brooklyn’s sewer system. The double page spread appeared in the Infrastructure section of the paper and describes the operation of the dams to prevent pollution in the city’s rivers. The original article can be seen here:

http://www.nytimes.com/2012/09/16/nyregion/in-bowels-of-new-york-city-inflatable-dams-help-block-wastewater-overflow.html?ref=nyregion