Night time restrictions have been imposed on the Pettigo water supply from 11pm until 7am.
The restrictions are effective immediately.
This will continue for the foreseeable future and both Irish Water and Donegal County Council will continue to monitor the scheme carefully.
Irish Water says it and Donegal County Council are continuing to monitoring all water supplies across the county on a daily basis while this unprecedented dry spell continues.
The Lough Mourne and Inishowen water supplies are still classified as at-risk and customers supplied from these schemes are asked to be especially mindful of their water consumption at this critical time.
The public across the whole county are urged to continue conserving water in every possible way to ensure a continuous supply for all.
As the weather conditions remain warm and the drought is increasingly reducing water levels in rivers, lakes, and boreholes, production at water treatment plants is struggling to meet increasing demand.
As well as reducing consumption, we are appealing to the public to report leaks on the public water network to 1850 278 278 and to repair private side leaks in both homes and in businesses.
The public are asked to change their mind set on water usage and to conserve water now and for the months ahead, as it will take many weeks and even months for raw water levels to restore in rivers, lakes, and boreholes and for treated water levels to restore in our storage reservoirs.
Across the country Irish Water is working with local authorities to do everything possible to conserve water availability, examining how we can make further inroads into leakage by mobilising extra crews and seeking maximum public cooperation in saving water.
Over 30 water supplies are under night-time water restrictions and over 130 water supplies at risk due to high consumption. We are tankering water from larger schemes to top up reservoirs where levels are falling and trying to protect borderline supplies so as to protect water supply to homes and businesses. This work becomes more challenging as the drought impacts spread nationally and the reserves of water fall across the country.