There's a been another major burst on the main pipe from the Eddie Fullerton Pollan Dam, this time at Fahan, leaving thousands of homes without water this morning.
The burst happened last night and crews began work on it early this morning.
Supplies have been affected in Fahan, Burnfoot, Inch, Bridgend, Burt, Carrigans, Killea, Newtowncunningham, Manorcunningham and surrounding areas.
Some homes in the Killea, Carrigans and Newtowncunningham areas are now being temporarily supplied from Derry.
Cllr Jack Murray says at this point, it's hoped services can be restored by 3pm.
He says the leak is a serious one............