26 August 2015 - This year’s Mail & Guardian Biodiversity Stewardship Award was recently awarded to the Cape Critical Rivers Project, which is a partnership between the Freshwater Research Centre, the Endangered Wildlife Trust, CapeNature and the Department of Environment and Nature Conservation (DENC).
One project that won an award was a ground-breaking river flow monitoring system that aims to bridge biodiversity conservation with water resource management in the Western Cape in a new, original way, on which Aurecon provided substantial contribution in terms of expertise and innovation.
Aurecon’s Hydrology Specialist, Louise Dobinson, says that this type of conservation intervention aims to correct a mistake that was made in the Cape Rivers many years ago.
“Alien fish were introduced into the rivers for sporting purposes. The Western Cape’s fish didn’t meet the sporty requirements of anglers, but these fish aren’t endemic to these waters so they predate on local fish. Essentially the introduction of these fish into local rivers led to many fish species becoming endangered,” says Dobinson. Additionally flows in the rivers have been severely modified through abstraction and the construction of dams.
The system that was created as part of this project offers a cost-effective, simple way to measure the flow of water in critical rivers around the Western Cape, predict the flows that are required to maintain the fish populations, and then to compare the two and visually show where actual flows that are measured are not meeting the requirements for healthy fish populations.
The flow of water in Western Cape rivers is very seasonal. During the spring and summer months, unsustainable levels of abstraction from rivers for irrigation purposes reduces the flow in key aquatic habitats to the extent that these habitats become unsuitable for spawning by our indigenous fish species.
“The monitoring equipment will be able to monitor the volume of water in the rivers and therefore indirectly, assist farmers in managing their water resources,” says Dobinson.
The data that the system captures will enable the Cape Critical Rivers to estimate water resources use, ascertain whether the ecological reserve is being met in key catchments - and if not, work towards the development of best practice guidelines for water conservation or re-allocation measures that will ensure that it will be met in the future.
The project is driven by the Endangered Wildlife Trust and one of its goals is to implement the conservation actions outlined by the drafted Biodiversity Management Plans (BMP) for the Endangered Clanwilliam sandfish and the Critically Endangered Barrydale redfin. These plans are in the process of being formally gazetted, after which they will become amongst the first legally binding BMP’s for any freshwater species in South Africa.
“Approximately 10% of Southern African freshwater fish species occur in the relatively small geographical range of the Cape Critical Rivers, making it a global diversity hotspot. The Mail & Guardian Biodiversity Stewardship Award is testament to the value of the work being done to ensure biodiversity conservation and water resource management for the rivers in the Western Cape,” comments Christy Bragg from Cape Critical Rivers.