Sponge Cities and Nature-based Solutions Integrating climate action for resilience and livability

Sponge city addresses climate-related risk of urban flooding and drought. An ecosystem-based approach to adaptation is applied using Nature based solutions and integrating green-blue and gray infrastructures. Asian and European cases are discussed.

Stefan Rau

Moderator

November 5, 2024 | 09:00 - 10:30

SDGs in Action - room C

Asian Development Bank ADB

Philippines

English

Reference:

SDG-C 1

WUF12

SDGs in Action

Summary

Guiding questions:
How can cities brace against massive climate related disaster risks like flooding, landslide, storm surge, sea-level rise, drought and heat? Can systematic use of natural systems and green spaces be effective resilience measures while delivering many additional livability and equity benefits? How to plan on local and urban region level, i.e. risk-informed planning with no-build zones and green spaces in rapidly urbanizing urban regions be effective as integrated sustainable urban development and climate action, especially for rapid new urban development in Asia and Africa? Can retrofitting existing urban areas be effective integrating green and gray infrastructure for resilience? What are experiences from Sponge City programs and projects, i.e. in the People’s Republic of China (PRC) and elsewhere? Can it be replicated in Asia and Africa – as it already is in Europe and Oceania?

The event:
It will bring together people from multinational agencies, national and local governments (PRC, Thailand, India and reach out to others in Asia and Africa), communities, private sector, NGOs, CSOs, academia and professionals of planning, human geography, ecology, landscape design, engineering, climate, biodiversity, social science, finance and economy.

Impact, lessons learned, benefits and challenges from projects and programs:
Representatives from local governments, CSOs, NGOs and private sector stakeholders will share impact stories, benefits and challenges from implemented projects. Professionals will share technical aspects of projects and principles of climate risk assessment, adaptation options and sponge city green-blue system planning, construction/rehabilitation and maintenance in PRC and other countries.

Policies, technical guidance and national programs:
Representatives of national government (PRC and others), think tanks and academia will summarize how guidelines and policies were developed, adopted, disseminated and used to mainstream sponge city, as well as funding programs for pilot sponge cities were implemented. International agencies like ADB and others, and other developing countries and will provide an overview and share lessons from across countries on policies, institutional responsibilities and finance and offer a matrix of applications and recommendations for consideration of other countries and cities to replicate. ADB and development partners will share experience from project and program support in Asia and Pacific and report its current and future actions on policy, guideline and program development.

Replication and scaling up:
ADB will launch a Sponge City support program support to Thailand and other Asian Countries with partnership support from PRC. Support to countries in Africa will be discussed and partnerships be promoted. Representatives of cities from around the world from the event partners and participants will be engaged to report on sponge city applications.

Objectives

The challenge and solutions:
When we build cities we pave over prior green spaces with buildings, roads, plazas. Rainwater runs off and needs to be managed. Mostly that is done through gray infrastructure systems like drainage pipes. During heavy storm events roads, sidewalks, plazas and parks may be flooded because the masses and speed of the water discharged are too large for the gray infrastructure to handle. To manage this excess stormwater several cities in the past built deep tunnel and storage systems. And still these may be overwhelmed by torrential rains already happening more frequently in the changing climate. The concept of sponge city addresses these challenges and captures and slows down stormwater before it is discharged into rivers. An ecosystem-based approach to adaptation is applied using NbS (more details below).

Networking:
The event aims will bring people together from multinational agencies, national and local governments, communities, private sector, NGOs, CSOs, think tanks, academia and professionals to promote meet and greet and new networks for further exchange and mutual learning.

Learning the mechanics and measures of Sponge City:
Participants will get an understanding of how sponge city works, objectives and NbS for rainwater management and various other ecosystem service benefits. Participants will learn about climate risk assessment, risk-informed planning, prioritization of adaptation actions and sustainable finance.