In order to understand how Archie is really performing good quality records of flow data are required at the site. Equipment has been installed permanently in the river to monitor the flow continuously over the next year but this requires calibration to give values of flow.
The tests at the weekend were the first of several to do this using a process called ‘dilution gauging’. This involves injecting red dye of known concentration into the river and measuring the concentration downstream over a few hours, from this the flow in the river can be calculated.
The work has been agreed with the Environment Agency and is totally harmless to flora and fauna.