A Research Approach to Develop an Ecologically Inspired Water Sensitive Planning and Design Framework for Delivering Climate Resilient Cities: A Case Study of Colombo, Sri Lanka

Abstract

Many developing countries are expected to be at higher risk due to the growing impact of climate change and natural disasters. As urban catchments in those cities become vulnerable to climate change, well known adverse urbanisation impacts can be severely increased. In particular, urban flooding remains a major tropical environmental hazard commonly occurring among developing countries in the South-Asian region, including Colombo, Sri Lanka. Current urban development should focus on developing climatic resilient strategies to support climatic adaptation activities. Considering planning, geographical and natural consequences, it is important to add to the existing knowledge of urban stormwater management and flood control in the Colombo urban area. Currently, there is a lack of attention in planning to the development of flood minimisation and adaptation practices in Colombo that consider the catchment scale as the basis of development. There is a need to integrate the services of catchment ecosystems with catchment scale planning. When developing approaches to manage stormwater there is also a need to consider plan preparation and implementation mechanisms that are influenced by institutional governance. Reviewing the existing literature, the researcher identified that current planning practices do not adopt a holistic approach that adequately considers both natural and human-induced elements of urban catchments to address stormwater management. The study identifies water as a central element in urban catchments, and argues planners must strategically deal with water and the landscape while creating closer links between nature and urban development to achieve resilient outcomes. Taking into account these two aspects, an alternative theoretical framework called Water Sensitive Planning and Design (WSPD) was developed using Colombo as the main case study area of the research. The overarching research question of the present study is: “How can a theoretical holistic planning framework be developed that adequately considers both natural and human-induced elements of urban catchments to address issues of stormwater management in cities situated in a tropical context?” The research question was addressed through a combination of content analysis of documentary data, spatial analysis and thematic analysis of interviews conducted with planning experts situated in the case study. Through the literature review and case study findings, the researcher developed and proposed the theoretical framework of WSPD, comprising two components – design/development, and delivery. To accomplish the first component, a spatial planning unit for development of water sensitive planning outcomes was identified, which the researcher termed ‘catchmentscape’. Using case study findings, two complementary WSPD scenarios were developed with the aim of self-regulation of stormwater within the urban catchment, recommending initiatives and design elements for natural elements and human-induced elements of the catchmentscape respectively. The delivery component of the WSPD framework leverages Multi-Level Governance theory as a way of implementing WSPD within catchments to overcome barriers in professional practice, plans and policies, and institutional governance that were identified through interviews with planning professionals in Colombo. The decision to propose WSPD as a new theoretical framework was inspired by ‘designing with nature’, within the legacy of Ian McHarg and the challenge of establishing closer links between landscape structures and functional relationships of catchments. The study considers how urban ecosystem-based adaptation can be enhanced by integrating WSPD approaches to deliver a flood resilient urban environment in the Colombo catchment. The case study findings in Colombo and the WSPD theoretical framework developed through the research represent original contributions to knowledge of stormwater and flood control management.