Redmires Reservoir in the south-west of Sheffield was built between 1833 and 1854 to provide safe drinking water following the Sheffield Cholera Epidemic of 1832. Made up of three separate bodies of water, the reservoir has a circular bellmouth overflow (plug hole) made from stone, ensuring excess water is safely discharged during increased rainfall. The infrastructure of the reservoir includes many types of technology, such as digital devices powered by solar energy that monitor rainfall and water depth. Drawing attention to the reservoir's thresholds, interface and devices, this film highlights the operational yet vulnerable status of these infrastructures.