Environmental group Interface Development Interventions is pushing for a permeable paving system in parking areas, gardens, parks and open spaces to help lessen the surface water run-off during heavy downpour that worsens flooding in urban areas.
IDIS acting executive director Chinkie Pelino-Golle told MindaNews on Sunday that the permeable paving system can also minimize the albedo effect compared to the traditional concrete surfaces that can increase atmospheric heat.
She urged the local government unit (LGU) to create a policy that would encourage establishments to install permeable pavements in place of pure cement pavements.
She said they will submit a policy paper to the LGU and City Council to consider the use of permeable pavements in drafting the City Development Plan and Infrastructure Development Plan.
“We conducted a study on it and we have validated that here in Davao City, we have establishments that have installed permeable pavements. They underscored the importance they get from it such as aesthetic, and flooding is lessened in their area,” she said.
She said the concrete pavement loses the ground’s absorptive capacity and traps the rainwater due to its “zero porosity composition” unlike the permeable pavement, which allows rainwater to percolate underground.
The permeable pavement is usually made of blocks, bricks, rocks, stones, recycled and other permeable materials.
“Dili na maabsorb ang water kay cemented na halos ang surface sa yuta (The rainwater can no longer be absorbed because the surface is already cemented). If we will install permeable pavements, we are allowing some water to be absorbed by the soil, so flooding will also lessen,” she said.
An IDIS study on “Assessment of Permeable Paving Systems of Selected Establishments in the Central Business District of Davao City” shows that the city’s rapidly increasing urban growth due to migration and rise of population will demand more construction of establishments leading to massive surface covering of groundwater recharge areas and open spaces.
Citing data from Philippine Statistics Authority (PSA), the city’s population grew from 1.1 million in 2000, 1.4 million 2010 and 1.6 million in 2015.
The study said establishments will rely mainly on using conventional concrete since construction is quick and easy labor but it poses ecological disadvantages that contributes to stormwater flooding and ponding, atmospheric temperature and air and water pollution.
“Majority of stormwater run-off volume heads directly to the drainage systems leading to overflowing and flooding,” it said.
The study added that among the advantages and characteristics of permeable pavement are that it will help in groundwater recharge while preventing soil erosion problems; prevent the build-up of sub-surface water pressure that leads to road cracks; filter and trap pollutants, especially atmospheric carbon and hydrocarbons; provide opportunities during redevelopment and reconstruction due to easy disassembling than impermeable concrete pavements; help protect critical watersheds in sub-urban areas; component in processes of low impact development and sustainable draining systems; and reduction in the amount of drainage canal requirement. (Antonio L. Colina IV / MindaNews)