River Obstructions
(Potential Sites of Hydropower Opportunity)

All the barriers were identified and mapped from OS MasterMap data, using the Digital River Network as reference. Head and flow values were used to generate potential power outputs expressed in terms of total capacity. Where available, Lidar data (vertical accuracy of 25 cm) was used to calculate the barrier height (head); otherwise, SAR data (vertical accuracy of 100 cm) was used. A number of data sources were used to estimate flow such as EA's Water Resources GIS database and flow data from gauging stations across England and Wales. The flow available at each particular barrier was calculated as the average flow (Qmean) minus the flow that is exceeded 95 % of the time (Q95). The environmental sensitivity associated with exploiting each barrier was assessed using EA compiled Fish Classification Schema data from the Water Framework Directive and Special Area of Conservation location dataset.