Urban drainage system design in a coastal lowlands city using a multilayer quasi-2D modeling- Case Study of Maricá, Brazil

Abstract

Urban drainage systems (UDS) are crucial for managing stormwater in cities. The failure of UDS can lead to severe flooding, causing damage to infrastructure, property, and environment. Their design and implementation often face significant challenges and in coastal lowland cities, these challenges are compounded by the influence of sea tides. Designing these systems in areas with tidal influence requires careful consideration of factors such as sea level rise, tidal patterns, and the topography, making the use of simplified hydraulic equations, such as Manning, unfeasible, as it does not represent the backwater effect. The complexities of these designs and the use of unreliable methods often result in increased costs and technical difficulties, making it a critical area of urban planning and engineering. This paper aims to present the design process of the urban drainage system in a coastal lowland city using the multilayer quasi-2D model MODCEL. The simulation was developed for a study area located in Maricá, Rio de Janeiro, Brazil. The area has a disordered urban occupation aggravating the challenge of project. The design process with hydrodynamic modelling resulted in a functional drainage network, capable of draining a 10-years storm considering backwater effects of high tide and river stage rise.