Installation of Uganda’s First Spillway Gates Nears Completion at Achwa II

Dyrhoff Ltd is currently supervising the installation of two Obermeyer spillway gates it has supplied as part of the Achwa II hydropower project in Uganda. The Project is located near Gulu in the north of the country and the civil contract is led by PAC Uganda, branch of the Italian construction company PAC Spa. The 42 MW hydropower plant is the first in a cascade of others on the river Achwa. The two spillway gates each measure 3.5m high by 33m wide, and will enable full regulation of the flow, helping optimize power output throughout the year.

Achwa 1

Actuated by air bladders, the gates require little maintenance and are environmentally very clean

Leeds Flood Alleviation Scheme Wins NEC Large Project of the Year 2017

Phase 1 of the soon to be completed Leeds Flood Alleviation Scheme (LFAS) is one of the largest river flood defence projects in the UK, and has been designed to reduce the risk of substantial physical and economical damage, which can occur from flooding. In all Dyrhoff Ltd supplied five spillway gates as part of the scheme, at sites in Crown Point in the centre of the city, and further downstream at Knostrop. Read the full article hereDCIM100MEDIADJI_0018.JPG.

Image courtesy of BAM.

Leeds Flood Alleviation Scheme – New Video Released

Construction of the Leeds Flood Alleviation Scheme is progressing well, with two of the three spillway gates at Knostrop weir now in operation. In addition, the scheme comprises two further gates at Crown Point in the City Centre, scheduled for installation in 2017.

September - Leeds Knostrop

When completed, the five pneumatic spillway gates will regulate flow, and will be lowered in high flow conditions to reduce the risk of flooding. The scheme is one of the largest flood defence projects currently under construction in the UK.  Leeds City Council have released a flyover video on their website to showcase the progress so far:


Donnacona Project Completed

Dyrhoff have had a busy twelve months in Canada, supplying no fewer than seven rubber dams in the country this year. Four rubber dams were installed as part of the Donnacona hydropower plant in Quebec, located on the Jacques Cartier River near the towns of Donnacona and Cap Santé. The Donnacona rubber dam replaces the old wooden dam at the site, originally built in 1918, after it suffered major damage in May 2014. After careful consideration, owners Algonquin Power & Utilities Corp., working with consultants WSP, opted to install an air inflated rubber dam in its place.

February - Donnacona

Dyrhoff’s newly installed rubber dam at the Donnacona Power Plant, Québec.


The new Donnacona rubber dam comprises four spans, each measuring 1.95m high x 23m wide. The inflatable dam will provide water level management for the Donnacona dam and nearby hydropower plant. The rubber dam will normally be operated in the fully inflated position for normal upstream water level control, and will start deflating once the headpond reaches a pre-determined upstream water level, allowing flood water to pass through and preventing flooding upstream. In addition, the dam will make it possible to pass the run-off from very large storms without flood danger, by deflating/opening one or more of the rubber bladders until the upstream reservoir water level has receded to an acceptable level. Dyrhoff has designed the dam for frequent and regular operation, and it is expected that each span will be deflated on average about 5 to 10 times a year, due to high upstream water levels. The inflatable dam has been designed to fully deflate or deflate in under 45 minutes. Following completion of the civil works by contractors Pomerleau, installation of the rubber dam took less than twenty days, under supervision of Dyrhoff. Initial commissioning tests took place in November and the dam is expected to enter operation in the New Year, with energy production at the 4.8MW plant resuming shortly thereafter.

Dyrhoff Wins Contract to Supply Obermeyer Spillway Gates at Uganda’s Achwa II Power Plant

Dyrhoff is proud to announce that it has been selected to supply two 3.5m high x 33.0m wide spillway gates at the Achwa HPP2 hydropower project, located near Gulu in the north of the country. This will be the first use of the technology in Africa, and Dyrhoff’s second project on the continent. The gates were selected for their proven reliability in harsh environments and minimal maintenance requirements. Works are scheduled to begin in March 2017.




Dyrhoff will be supplying two Obermeyer gates as part of of the Achwa HPP 2 project, similar to the one above 

New Caffarella Spillway Gate is Commissioned Following ‘Drop-In’ Installation

Work on the installation of the new Caffarella spillway gate in Italy proceeded swiftly earlier this month. The complete gate and its actuation system were pre-installed on a steel frame, enabling the whole to be effectively lifted into the river.



Fig.1: The gate assembly being lifted into the river at the Caffarella plant, Italy.


Fig.2: The gate assembly prior to being embedded in concrete.


Fig.3: The completed gate

The gate’s compact size, measuring 1m high x 25m wide, made this a relatively straight forward process, with installation of the main gate assembly being completed in a single day.

Palmer Falls Installation Completed

Dyrhoff recently supervised the installation of a new 4ft high x 43ft wide air-inflated rubber dam at the forebay spillway of the Palmer Falls hydropower plant, located on the River Hudson, near Corinth in upstate New York. The rubber dam is the third installed at the facility and will be used as a fully automated flashboard system, designed for year-round operation, and used to sluice ice during the winter.

Palmer Falls1

Fig.1: The new rubber dam at Palmer Falls undergoes inflation tests

As part of the project, plant owners Curtis/Palmer also ordered two replacement rubber bladders to replace the original Bridgetsone rubber dams, in operation since 1987. Measuring 6ft high by 205.5ft and 142.3ft long, the two spillway bladders are reaching the end of their design life and will be replaced within the next couple of years.

The new forebay spillway rubber dam controls and mechanical equipment were integrated into the existing spillway rubber dam controls and equipment.

Palmer Falls2

Fig.2: The existing rubber dams at Palmer Falls, originally installed by Bridgestone, to be replaced by Dyrhoff after 30 years of continuous operation. 

Dyrhoff will supply replacement rubber membranes for the two other dams at the site, originally supplied by Bridgestone in the late 1980s and now reaching the end of their working life. The rubber dams are scheduled for replacement in 2017.



Dyrhoff Awarded ISO 9001 and ISO 14001 Certification

Dyrhoff Ltd is pleased to announce that it has successfully achieved certification to the internationally recognised ISO 9001 Quality Management Standard and ISO 14001 Environmental Management Standard following an assessment by the British Assessment Bureau this month.

Certification Badges_CMYK (White) ASSETS_(Mar 21)Certification Badges_CMYK (White) ASSETS_(Mar 21)

For 25 years, Dyrhoff has been a world leader in the design and supply of inflatable rubber dams and spillway gates. Over the last quarter of a century, the company has supplied over 150 systems across 4 continents.

Dyrhoff have an exclusive license to supply rubber dams conforming to the Sumitomo design and is the exclusive European agent for the Obermeyer spillway gate system. Their ISO 9001 and ISO 14001 certifications underlines the company’s seriousness and integrity in its engineering field,  and actively demonstrates its ability to deliver quality and environmentally sound products and services, as verified by an independent third-party.

Each year, an independent assessment will be carried out by the British Assessment Bureau to ensure Dyrhoff continue to demonstrate it is meeting the requirements of both ISO 9001 and ISO 14001 on an ongoing basis. This rigorous assessment is backed by UKAS accreditation, which is supported by government.

ISO 9001 involves the implementation of a Quality Management System, which helps organisations to formalise processes, resulting in improved performance and – as a result – improved customer satisfaction. ISO 14001 involves the implementation of an Environmental Management System, helping organisations maintain an effective environmental policy and action plan to manage their impact on the environment.

The benefits of registration to ISO 9001 Quality Management Standard include:

  • Streamlining an organisation’s procedures;
  • Bringing consistency to an organisation’s product / service delivery;
  • Reducing cost and rework;
  • Improving an organisation’s management practices;
  • Enhanced status;
  • Competitive advantage;
  • Lower insurance premiums.

The benefits of registration to ISO 14001 Environmental Management Standard include:

  • Organisations are able to demonstrate their environmental credentials;
  • Win more business;
  • Achieve operational excellence;
  • Reduce overall costs, overheads and wastage through the implementation of an environmental policy;
  • Gives organisations a focus on proactive management;
  • Ensure legislative awareness and compliance as a business.

Commenting on the fantastic achievement, Gabriel Topalian from Technical Sales at Dyrhoff said;

“In this industry, quality and a clear environmental mind-set is imperative. Achieving certification to ISO 9001 and ISO 14001 demonstrates our commitment to offering our customers the very best product and service as well as the assurance they are dealing with an environmentally sustainable company. We are delighted to become ISO certified, and look forward to the successes our achievements will bring throughout 2016 and beyond.”