Laguna de Bay desperately waiting for desilting
Almost a month after Typhoon Ulysses hit the country, some lakeshore areas in Biñan City in Laguna remain submerged in flood water. The Laguna de Bay reached 13.6 meters above sea level, above the lake’s maximum critical level of 12.5 meters.
Over the years, the sewage canals have been fixed, the major river dredged, a comprehensive hydrology study done. But for now, all the city could do is to wait for the water to subside, pray that it doesn’t rain again soon, and ask the national government to finally act on desilting the largest lake in the country.
MASTER PLAN FOR FOOD AND DRAINAGE
At the webinar, Beyond the Concrete: A Multi-Sectoral Approach on Housing, held last weekend, architect Felino Palafox Jr. said that the government already has a master plan for flood and drainage in Metro Manila. “The bad news is that it will be completed in 2035,” he quipped.
“In stressed areas liable to flooding and other disasters, we should control development until the necessary structures are put in place, like the dredging of Laguna Lake,” he said, adding that Metro Manila still has 8,000 hectares of vacant land.
While waiting for legislative measures to take place, there are practical solutions that can immediately be done to save at-risk Filipino families and properties, according to Marcelino Mendoza, chairman of the Organization of Socialized and Economic Housing Developers of the Philippines (OSHDP) and president of Socialized Housing Alliance Roundtable Endeavor (SHARE).
“The newly created Department of Human Settlements and Urban Development (DHSUD) is mandated under Section 20 of the Implementing Rules and Regulations of RA 11201 (the enabling law) to formulate national housing policies and standards for resettlement housing and programs for families occupying danger areas such as waterways,” Mendoza said.
He expounded, “Section 19 of the same IRR gives DHSUD the power to formulate a framework for resilient housing and human settlements as a basis for mechanisms for post-disaster housing and resiliency planning to protect vulnerable persons and communities in hazard-prone areas from the adverse effects of climate change and disasters.”
Mendoza also suggested that Comprehensive Land Use Plans (CLUP) must be immediately updated at the provincial, city or municipal level. It should be reviewed to ensure that areas declared as flood zones should not be developed, especially if these act as catch basins.
He agreed that desilting of waterways in the path of flood and dam water must be prioritized, and financed regularly by the Department of Public Works and Highways, National Irrigation Administration and local government units.
“The budgeting process in the Philippines gives priority to new building infrastructure and a reallocation toward maintenance is a necessary change, given the experience of the last three typhoons,” Mendoza also said.
URBAN WATER MANAGEMENT SYSTEMS
In a sea of additional infrastructure solutions suggested to combat the worsening climate disasters, advocates of green architecture proactively push reforestation in denuded mountains (e.g., Sierra Madre) and watersheds (e.g., Marikina Lake Watershed and Laguna Lake Watershed), enhance the mangroves and use sustainable building materials.
Said Palafox, “After Build Build Build, there should be Plant Plant Plant.” The renowned architect also supports the sponge city concept as part of urban planning and flood prevention in Metro
Manila and surrounding areas.
“The Sponge City is part of green infrastructure, where you absorb or harvest the rainwater and repurpose it for irrigation, fire prevention, and so on. It’s being done in many cities, like in India and China right now,” he explained.
Globally, governments have been considering various urban water management systems.
The UK established sustainable drainage systems which consider quality and quantity of water and can use public recreation measures, such as a rain garden, to mimic natural drainage. Australia created the water- sensitive urban design (WSUD), which takes into account the hydrological cycle as well as water conservation measures before developing an area. The US has LowImpact Development (LID) that manages rainwater at the source and aims to restore the hydrological cycle before starting any construction.
Much can also be learned from European countries, such as the Netherlands, whose large part is situated below sea level. Germany, meanwhile, has different rainwater collection and recycling systems, separate from rainwater purification and filtration systems.
The Philippines does not have to look far for best practices, actually. Some traditional farmers in upland areas still use centuries- old rainwater collection and recycling systems to bring water up mountainous farms.
I personally saw this in Sebul Farm in South Cotabato. The sustainable farm solved its water problem by creating a hydraulic ram pump, which can irrigate the farm continuously, without a power source.
Whether in farming or urban planning, there are sustainability lessons we all can heed.
“After Build Build Build, there should be Plant Plant Plant.”