SMEC is helping to deliver the Cressbrook Dam Safety Improvement Project with Seymour Whyte and Toowoomba Regional Council in Queensland, in order to meet acceptable flood capacity modelling guidelines as revised by the Australian National Committee on Large Dams.
The project will ensure that the structure can safely handle surplus water during intense rainfall by raising the dam crest height, whilst also aligning the structure with current engineering design standards and safety regulations. As a result, enhanced flood capacity and resilience will be delivered to the dam, whilst maintaining its current 81,900 ML drinking water storage capacity.
SMEC will soon commence the detailed design phase, encompassing the dam spillway widening, embankment increase and design configuration of the plunge pool. There will also be provision for natural fish migration and integrating circular economy principles including the reuse of rock.
Construction is expected to start during 2024 with key works completed in late 2025. Some ancillary works may be required to the end of 2026.
Malawi
The Malawi Northern Region Water Board (NRWB) has also recently appointed SMEC to prepare the Lunyangwa Dam Safety Management Plan.
Constructed in 1992, the Lunyangwa Dam is the main source of water for the piped water supply system in Mzuzu City. Over 250,000 people currently depend on the dam for water but the population of the catchment is estimated to be growing rapidly, with some projections suggesting it could reach 500,000 by 2030.
To meet increasing demands, NRWB proposes to increase reservoir volume from 4.36Mm³ to 5.54Mm3 which will entail:
- Raising the concrete spillway by 1.5m.
- Construction of a 2m parapet wall on the existing dam crest with fill behind it.
- Inlet modifications at the intake tower.
- Reinstatement the dam monitoring equipment and instruments
To ensure safe operations of the modified dam, SMEC will deploy a team of dam safety experts and specialists to develop a comprehensive dam safety management plan that meets the requirements of the Malawi Dams Safety Act, 2015 and ICOLD guidelines. These are expected to be completed by June 2024. The designs for raising dam and spillway heights have been prepared by others.
The transfer of technology and capacity building is very important for safe and sustainable operations and maintenance and so as part of the project, SMEC says it will develop a training programme to upskill counterpart staff selected by NRWB.
With loan financing from the European Investment Bank, the project forms part of the NRWB Water Efficiency Project which aims to improve water resources management in the region. Increasing the volume of the dam is one of the interim measures to ensure continual supply of water in Mzuzu city while sourcing financing for a long-term water supply solution.
Redevelopment
Ontario Power Generation (OPG) is gearing up to redevelop the 117-year-old Kakabeka Falls Generating Station, in northwestern Ontario, Canada. The second-oldest hydro station in the company’s fleet, the ageing infrastructure has much of its original equipment. Currently boasting a peak output of 24.4MW, OPG has initiated plans for a comprehensive redevelopment project aimed at ensuring continued safe and reliable power generation for the next 90 years.
Construction is scheduled to begin in 2025, with completion anticipated by 2027. The ambitious plan includes building a new powerhouse extension situated upstream of the existing facility on the eastern bank of the Kaministiquia River. This will feature two state-of-the-art turbine-generating units, capable of producing approximately 27MW – a 13% increase from the current capacity. Simultaneously, the existing generating units and ancillary equipment will be removed from the original powerhouse, which will be preserved in its current location, and four penstocks and the surge tank will also be replaced.
Situated within the traditional territory of the Fort William First Nation, the Kakabeka Falls redevelopment project is expected to yield economic benefits for local Indigenous communities. OPG has been working closely with the Fort William First Nation, ensuring community consultation and input are integral to the project’s planning stages.
This article first appeared in International Water Power Magazine.
