507 / 2024-05-26 18:02:34

Technical and Financial Evaluation of Eco-drainage and Permeable Pavement for Urban Sponge City Concept

Sustainable Drainage, Permeable Pavement, Infiltration Chamber, Flood

Subtheme 1: Water-related Hazard and Risk Reduction > Topic 5: Resilient City Against Water Hazard

The rising economic activity in urban area of Indonesia has led to the transformation of previously green areas into residential and commercial zones, consequently affecting the management of storm water and water conservation. Sustainable urban drainage system helps to manage stormwater runoff effectively, reducing the risk of flooding, and pollution of water bodies. Urban area in Malang City, a buffer area of Surabaya as East Jawa Province Capital was selected as study area. The experiment was conducted in an administrative region with 1124 km2 area in Malang City that was frequently inundated. In this study, the field experiments aimed at designing permeable pavement particularly to obtain the parameter of concentration time, porous concrete storage volume, and infiltration rate is conducted. The typical design for infiltration chambers and bio-absorption holes was also developed as part of the design process. The technical aspects are evaluated in terms of the effectiveness of the facilities in reducing flood discharge. The facilities are also assessed in terms of life-cycle cost of investment, maintenance, and flood risk reduction value. The results showed that the eco-drainage system can reduce the flood discharge in the main channel from 1.37 m3/s to 1.64 m3/s. The area requires 118 infiltration wells, 105.213 bio-absorption holes, and 1098 permeable pavement with a thickness of 0.06 m. The investment could achieve a Benefit-Cost Ratio (BCR) of 1.5 over a 5-year economic lifespan. In the conclusion of the paper, the authors recommend integrating permeable pavement suitability and planning control indicators with urban functional districts to guide the planning and regulation of urban sponge city. This research benefits urban areas management aiming to reduce flood risks, enhance environmental sustainability, integrate urban planning, provide cost-effectiveness, and ensure long-term resilience.