Yorkshire Post photographers captured exposed mudbeds at both Lindley Wood Reservoir, near Otley, and Swinsty Reservoir, near Harrogate, on Monday.
Yorkshire Water have already admitted that water levels at some sites have dropped to around 60 per cent of capacity as demand for drinking water has been so high.
Lindley Wood is a compensation reservoir, which means it is not linked to the supply of water to homes, but is there to take excess water from Fewston and Swinsty reservoirs nearby.
Yorkshire Water do not send water to Lindley Wood during hot weather.