Uisce Eireann says Lough Owel's supply has been badly affected by the summer's warm weather.
Over 50,000 customers in Westmeath will continue to be affected by a water conservation order until October at the earliest.
The Mullingar Regional Public Water Supply has been under a hosepipe ban since May this year, with Uisce Eireann extending it for an additional month up until October 13th.
Lough Owel is the source of the supply which serves customers in Mullingar and its surrounding areas, with the semi-state body stating levels at the lake remain critically low.
Uisce Eireann says despite recent rain, record breaking summer heat meant underground springs feeding the lake have slowed down the conservation process.
Hosepipe bans also remain in place for people living in Oldcastle, Kells, and Millford.
Two Offaly Women Selected For National Nature Restoration Portrait Series
Westmeath Town Band Opens Recruitment To New Members
Laois Disability Centre Fails HIQA Inspection In Four Regulation Areas
Offaly Community Group Aims To Support Young People’s Physical And Mental Health
New Brian Cowen Biography To Be Launched In Offaly Tonight
Midlands Homelessness Figures Record Slight Monthly Increase
Credit Union Lending Surges As Mortgage Growth Continues Amid Merger Wave
37% Of People Aged 25 To 64 In The Midlands Leave School Without Third-Level Education