Residents in Barangay Addition Hills, Mandaluyong City collect delivered water amid a supply outage in parts of Metro Manila, March 15, 2019. Mark Demayo, ABS-CBN News

MANILA - Brothers Jaime Augusto and Fernando Zobel de Ayala on Wednesday said Manila Water is taking responsibility for "shortcomings" that led to a lack of water supply that brought misery to more than a million households.

The service outage affected some 1.2 million households in the east zone of Metro Manila, serviced by Ayala-led Manila Water. The west zone, under Maynilad Water Services Inc., was unaffected.

"A multitude of factors resulted in this lack of supply, and we take responsibility for our own shortcomings in the company. We recognize and understand the difficulties that all our customers are going through," the Zobels said in a statement.

Manila Water earlier attributed the problem to increased demand, lack of rains, delays in infrastructure projects supposed to boost supply, and the declining level of the La Mesa Dam, its emergency resource.

The concessionaire announced Tuesday that it will suspend the minimum charge for all customers affected by the outage, and waive fees for the whole March consumption of those who were most severely hit.

Manila Water's 8 to 12-hour supply availability at ground floor level has been restored to 97 percent, said the Ayala brothers.

"Please be assured that Manila Water is exploring all possible options to bring back services to the high levels that we are all accustomed to," the tycoons said.

"We continue to appeal for everyone’s patience as our teams at Manila Water are working hard and overtime to immediately and comprehensively remedy the situation. Resolving this situation requires support from all sectors," they added.

The duo also encouraged the public to conserve as their firm's teams "search for and implement immediate and long-term solutions to the water problem."

"We will double our efforts to restore services to the high levels that we have had and to ensure that future shortages such as these will not be repeated. We are deeply grateful for your understanding," they said.

President Rodrigo Duterte has directed authorities to submit by April 7 a report on how it addressed the service outage, Metropolitan Waterworks and Sewerage System (MWSS) Administrator Reynaldo Velasco earlier said.

