After more than a week of water outages in parts of Metro Manila, Ayala-owned Manila Water was finally able to improve water availability to 96 percent in its concession area, covering at least 6 million people, by March 22, Friday.

But this doesn’t mean that water is again available for 24 hours. Instead, the company’s limited water supply is being rationed in a way so that almost everyone receives water at least 8 to 12 hours a day.

What triggered the water crisis

On March 4 and 5, Manila Water announced it would implement an “El Nino Water Supply Contingency Plan” for Taguig City, Pasig City, Marikina City, Quezon City and parts of Rizal. There were no details about how many hours the affected areas would lose water, except that it would start on March 6.

Manila Water showed ABS-CBN News a one-page illustration of their supply management plan, which was supposed to affect only a few areas. The full impact was supposed to be felt in June but according to Manila Water, the current situation is worse than what they planned for June.

During the release of Manila Water's advisories, La Mesa Dam, which serves as Manila Water’s buffer supply, was nearing its critical level of 69 meters.

On March 6, tens of thousands of households in Metro Manila lost water, including those not in Manila Water’s contingency plan. Manila Water claims that while they were ready for the increased water consumption of people in these areas, the reservoirs in some cities not included in their advisories got depleted due to panic water storing. On this day, water availability dropped to 89.9 percent.

The next day, it went down to 87.7 percent with only 45 percent of Mandaluyong having water coming out of their taps.

On March 11, La Mesa Dam breached its critical level.

This meant Manila Water could no longer draw its 150 million liters a day of water, which they had been using to augment its 1.6-billion liters daily allocation from Angat Dam.

It was later revealed that Manila Water had been experiencing a deficit since 2016 as water demand from its increasing service connections had surpassed its available supply.

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For the next several days, long lines of people with pails and water containers hogged the headlines and social media feeds of people in Metro Manila. Schedules posted by Manila Water were useless, according to residents who experienced water outages outside the assigned hours. People were losing their water supply without notice as high areas saw their reservoirs depleted.

Water tankers

During the early days of the shortage, people relied on water tankers and static tanks. In addition to Manila Water’s 24 water tankers, Maynilad lent five additional water tankers. MWSS said there were also tankers lent by the Red Cross, the Luzon Clean Water, and various local government units.

According to Dittie Galang, communications manager of Manila Water, they were deploying 156 vehicles at the peak of the water shortage. At least 12 percent of Quezon City’s barangays were being served by these tankers.

However, they were all still drawing water from Manila Water’s fire hydrants, which meant they were merely redistributing water instead of adding to the concessionaire’s limited supply.

Cardona plant

On March 14, Manila Water's Cardona water treatment plant in Rizal, which had been delayed for months, finally went online, feeding 24 million liters of water a day from Laguna Lake to Binangonan, Angono, Baras and Jalajala in the province of Rizal. However, this is not enough to meet the deficit as the La Mesa Dam can now only supply 50 million liters a day. The Cardona plant won’t be fully operational – equivalent to 100 million liters a day – until August.

• MWSS: Water shortage government's 'fault,' solutions underway

Rationing

By March 15, Manila Water employed a rationing system of closing certain valves and redistributing their supply to water-starved barangays.

For example, water flowing through Mandaluyong had been going straight to Manila’s gravity-fed system because of its lower terrain. So, instead of letting Manila customers get most of the water, Manila Water closed off their valves at certain hours. This allowed them to refill the San Juan reservoir and pump water to the surrounding barangays in Mandaluyong.

For several days now, Manila Water has been employing this balancing act of rotating the water outage throughout the East Zone of Metro Manila. Gravity-fed facilities had to be closed temporarily while pumping stations and reservoirs were stocked for areas that could not handle the low water pressure the system was also experiencing.

However, rationing meant other areas lost their water supply, so water availability went down to its lowest level of 87.5 percent on March 15.

Cross-border sharing

On March 18, the planned “cross border” supply sharing with Maynilad started. According to Manila Water's Galang, they have an existing connection in West Avenue, Quezon City that was opened again to allow 2 million liters a day to flow from Maynilad’s pipes to Manila Water.

Water regulator Metropolitan Waterworks and Sewerage System (MWSS) estimates that a total of 50 million liters of water a day will be transferred from Maynilad, which has a water surplus because of their plant in Laguna Lake, to Manila Water. However, this is easier said than done.

Galang said it would require some pipe laying, which might take weeks or months. And this can only be done in areas where Manila Water’s pipes are higher than Maynilad’s.

Deep wells

And as for the deep wells, which MWSS claims can supply 100 million liters a day, Manila Water still needs to test the water quality and get approval from subdivisions where some of the wells are located.

Last year, Manila Water started drawing water from a well in Rodriguez, Rizal, which yielded seven million liters a day.

During the Senate hearing on March 19, Manila Water President and CEO Ferdinand dela Cruz claimed that despite sending a request as early as 2017, the National Water Resources Board only allowed them to tap the deep wells of MWSS on March 14.

Manila Water said they hope to draw 40 million liters from the deep wells by April, but Galang said the most feasible now are six deep wells that will yield a total of 8.6 million liters a day.

“Most of these deep wells, may issue. Maraming deep wells, walang complementing lines. Kailangan maglagay ng pipes,” she said.

Another factor to consider is the concern of residents that pumping water from deep wells would cause land subsidence. According to the US Geological Survey, land subsidence is experienced when large amounts of water have been drawn from rocks or the ground. However, according to Manila water, there is no conclusive evidence of land subsidence in the MWSS deep wells.

The good news though is that because the deep wells were not used for a decade, their water levels have improved. Now it’s a matter of ensuring the water quality and confirming that it won’t result in land subsidence.

The 4% who still don't have water

Finally, after days of rationing and redirecting water through other means, Manila Water reached 96 percent water availability on March 22.

Those remaining without water are several barangays in San Mateo and Rodriguez, Rizal. They continue to depend on water tankers.

It will take a while before it all goes back to normal. The concessionaire has yet to get a substantial boost to its water supply. And with La Mesa Dam below its critical level, water has to be manually drawn using mobile pumps to serve the northern parts of the East Zone.

As Manila Water has said before, supply will only normalize when the rains come possibly by June this year.