‘CLEAR RIVERS, CATCH RAIN’
Harvest the rain using roof gutters and store it in barrels or tanks.
This is something ordinary residents can do to help minimize flooding, officials said.
Mandaue City planning officer Florentino Nimor J., an architect, said the city will implement an existing ordinance that requires households and establishments to install a “sandayong” or roof gutter.
“At least it would help delay the flow of water to the ground,” he said.
The excess water collected can also be used to water plants, flush toilets and wash floors.
Solutions as simple as having a downspout from the roof are being taken more seriously after a Sept. 18 downpour left major streets of Mandaue, Cebu and Lapu-Lapu cities under water following six hours of continuous monsoon rains during tropical storm “Mario”.
Bigger-scale methods of catching rain were recommended by the Department of Environment and Natural Resources (DENR) 7.
Gabion dams to slow down runoff water from the mountains should also be built, said Mandaue Mayor Jonas Cortes.
“The construction of catchments or small water impounding dams would address the ‘new normal’ of global warming and climate-related disasters when it comes to the magnitude of rains that come with a tropical storm or the “habagat”,” said Isabelo Montejo, DENR 7 regional executive director.
He said harvesting water should be part of a local government’s development plans to make the community more resilient.
“Captured water could be managed and used as a resource during summer for irrigation and other agricultural uses,’ he sadded.
FLOOD-PRONE ZONES
DENR’s geohazard maps have long identified areas in Cebu that are prone to flooding.
The top five in Cebu City are barangays Kasambagan, Labangon, Mabolo, downtown and the mountain barangay of Bonbon, and along the Guadalupe River.
In Mandaue city, seven flood-prone barangays are Subangdaku, Mantuyong, Umapad, Opao, Alang-Alang, Guizo and Paknaan.
Mandaue City, which has its own drainage master plan, has identified 54 flood-prone areas, 32 of which are major roads including A.S. Fortuna St., Hernan Cortes St., M.C. Briones and national highways in Subangdaku.
Since two major rivers, Butuanon and Mahiga, pass through Mandaue, the city gets flooding episodes during heavy rains.
Mandaue Mayor Cortes, who said Mandaue City has become the catch basin of flood waters coming from Cebu City, followed up his call for joint action to find a lasting solution to urban flooding “as soon as possible”.
He told Cebu Daily News he would seek the help of the Mega Cebu board during its next board meting, as well as meet with barangay officials.
“It is good for mayors to work hand-in-hand because our local master drainage plans wouldn’t work,” he told CDN.
Consultants of the Japan International Cooperation Agency (JICA) are presently drafting a roadmap for Metro Cebu to help achieve the 2050 Mega Cebu vision of sustainable urban growth for seven towns and six cities including Mandaue, Cebu, Lapu-lapu, Talisay, Carcar, Naga and Danao.
“I am asking the offices of the Department of Public Works and Highways (DPWH) in Cebu City and Mandaue covering the sixth district to sit down with city officials and come with joint mitigating measures like the construction of gabion dams in the upland areas,” Cortes said.
“Our upland areas are already denuded. Gabion dams minimize runoff water from the mountains and can prevent flash floods during heavy rains,” he added.
SHORT-TERM ACTION
The interim report of JICA, which covers storm water management, said what should be done in the short-term are:
1. Implement a “comprehensive study for a Metro Cebu Integrated Flood and Drainage System Master Plan”
2. Clean up rivers, creeks and drainages which are clogged by garbage and informal settlements
3. build small-scale rainwater storage facilities; and
4. build mini-dams
Although Mayor Cortes announced in his State of the City address that 50 percent of their drainage lines have been rehabilitated, the city’s sewers and drains couldn’t cope with the large volume of rain last week.
Another approach raised by the Cebu Uniting for Sustainable Water Foundation (CUSW) is to revitalize major rivers and develop eco-tourism parks there.
Downstream, where waterways reach urban areas, “there is no or little relaxation for citizens’ said the JICA report. To revitalize rivers, firms steps should be taken to remove garbage dumped in the rivers, relocate settlers away from the riverbanks and build sewage disposal systems to protect the river from pollution of industrial liquid waste.
The Philippine Water Code (Presidential Decree 1067) sets a buffer zone of three meters from water bodies and open spaces.