Revolutionary technology and a large dose of innovative thinking are helping fish migrate into a loch that supplies Inverness with water.
Scottish Water has installed a new tilting weir fish pass to not only secure the water supply to customers in Inverness but also to protect the migration patterns and survival of migrating fish passing through Loch Duntelchaig.
There were a number of challenges associated with this project, including the tight turnaround time associated with the construction programme. The work had to be completed by the end of September 2014 to ensure fish populations were not impacted due to construction work that could have prevented migration or the release of sediment into their habitat.
Caroline Olbert, from Scottish Water’s resource team, said: “At the fish pass fixed concrete walls were replaced with tilting weirs that are adjusted to match the water level in the loch. Fish passes are often designed to work at particular water levels but at Loch Duntelchaig parts of the pass now move with the changing water levels, meaning that the pools and weirs are always at their optimum level to allow fish to move upstream. The inflexibility of the old fish pass meant that less water was available for use by customers during dry weather, as the loch had to be maintained at a higher level to allow fish to continue to use it.”
Hugh MacPherson, Scottish Water’s project manager for the project, said: “This fish pass is unsurpassed in terms of how innovative the technology behind it actually is. It is the first tilting weir fish pass of its kind in the UK and, possibly, Europe. Cost has also been a great win for the team in that the whole project would have been a lot more expensive if it hadn’t been for the Greenbox.”
The utility’s project team embraced the latest technology to come up with a solution that would effectively meet both the business need to complete the job quickly, efficiently and cost effectively and the environmental needs of the migrating fish population.
This came in the form of strong partnership working with a company that are promoting the benefits of Greenbox technology and applying its capabilities to tilting weir technology.
The Greenbox is essentially an actuator, level sensor, solar panel, battery pack and control panel in a single, off-the-shelf unit which powers and moves the tilting weirs into the correct position, ensuring that fish passage can be maintained throughout the full operating range of the loch. It removed the need for expensive cables to be laid or wind/ solar solutions installed.
The Greenbox technology was installed by Aquatic Control Engineering Ltd (ACE). ACE specialise in the provision of water flow control innovations with expertise in the design of water flow control solutions without compromising fish migration.