MANILA, Philippines – The Department of Environment and Natural Resources (DENR) is targeting to plant three million trees in the next four years within the Upper Marikina Watershed in a bid to alleviate flooding in parts of Metro Manila and Rizal province.

“We have a target of three million trees in the Upper Marikina Watershed to be planted in the next four years,” Environment Undersecretary Carlos Primo David told reporters in a briefing on Thursday, September 5.

David said forest cover can dictate how much of the rainwater would be converted to floodwater.

“If I have good forest cover, I can tell you that majority of that rain will infiltrate into the ground and only a small portion, about 20% initially, will be converted into runoff or surface flooding,” David, a geologist and professor, said.

The recent flooding in Metro Manila and neighboring provinces has again brought up unresolved issues on deforestation and urbanization.

A network of environmental groups said the denuded forest cover of Upper Marikina Watershed had reduced its water absorption capacity.

They pointed at quarrying, deforestation, and “uncontrolled” development as main culprits of the denudation of the watershed.

“The floods in Rizal are not a natural disaster, but a man-made catastrophe born of corporate greed for profit and government corruption and complicity,” Kalikasan People’s Network for the Environment said in a statement on Thursday.

Land cover	Total area (hectares)	% of area
Intact forest	6,420.87	25.21%
Trees/shrubs/grass	15,493.30	60.82%
Agricultural	2,772.23	10.88%
Built-up	776.27	3.05%
Open/barren	11.12	0.04%

Meanwhile, David said the DENR already cancelled quarrying permits within the Upper Marikina Watershed since last year.

The reforestation of Upper Marikina Watershed, a protected area that is roughly 26,100 hectares, is often seen as one of the solutions to reduce flooding in towns within the 69,800-hectare Marikina Water Basin.

The Marikina Water Basic covers the urban areas in Marikina, Antipolo, San Mateo — areas reported to have experienced flooding in the wake of Typhoon Enteng.

“Even if we reforest the whole Upper Marikina Watershed, we will have to contend with all the rain that will fall in the Lower Marikina Watershed that gets converted almost entirely into floodwaters,” said David.

Lower Marikina Watershed refers to the rest of the Marikina Water Basin that covers around 43,700 hectares of land.

The “ambitious” target, as David described, comes 15 years after the inception of the government’s flagship reforestation initiative, the National Greening Program. It was not as “efficient as we wanted it to be,” David admitted.

To date, the program boasts of planting more than 1.8 billion seedlings within 2.17 million hectares of land.

The problem that some advocates identified in the accomplishment report is that the number of seedlings planted does not take into account the number of seedlings that actually grew and enhanced forest cover.

The DENR said it has partnered with the Department of Public Works and Highways to achieve the target of planting three million trees, as well as with WawaJVCo (responsible for the construction of the Upper Wawa Dam), various non-government organizations and concerned local governments.

– Rappler.com