Environmental monitoring
The Harbour Authority undertakes a range of environmental duties in accordance with the requirements of the Cardiff Bay Barrage Act and other environmental legislation. These include monitoring and maintaining water quality standards, and protecting and enhancing the natural and built environment.
The Harbour Authority has attained ISO14001 environmental accreditation, which demonstrates a commitment to reducing the impact of projects and operations on the environment. The environment team manages all issues relating to the environment in Cardiff Bay.
You can download the Harbour Authority’s Environmental Policy Statement.
Please report environmental incidents by calling Natural Resources Wales (24 hour service) on 0300 0653000.
Chemical water quality monitoring
Dissolved oxygen, salinity levels, temperature, pH and a number of other parameters are continuously monitored from 9 locations throughout the Bay. Readings are taken every 15 minutes – you can view the data on the:
The Cardiff Bay Barrage Act states that dissolved oxygen levels must be maintained above 5 milligrams per litre throughout the Bay. This standard was set to protect migratory fish, such as salmon and sea trout, which travel through the Bay on their way to and from their breeding grounds further up the rivers. Salinity levels are measured to ensure that the operation of the Barrage locks and sluice gates minimises the volume of seawater entering the Bay. This is important to ensure that a freshwater environment is maintained. Water samples are taken on a regular basis and analysed for additional water quality parameters, including metal salts and nutrients.
Biological water quality monitoring
The Harbour Authority worked closely with public health advisors from Shared Regulatory Services and Public Health Wales to develop working practices to minimise the health risks to water users.
Bacterial water samples have been collected for 19 years, and the data derived from these have led to the development of a predictive water quality model. This model is run on a daily basis to predict the water quality in advance, and the output used to inform stakeholders about which activities are possible on that day.
Other monitoring
Other monitoring is undertaken from time to time to improve our general understanding of the Bay environment, and provide information to the public and water users. The Harbour Authority has undertaken wave, wake and current monitoring, and bathymetry surveys to assist with various investigations and projects.
