Essential Eight: Environmental Protection and Strengthening of Ecosystems

"Protect ecosystems and natural buffers to mitigate floods, storm surges and other hazards to which your city may be vulnerable. Adapt to climate change by building on good risk reduction practices."


Ecosystems serve as protective buffers against natural hazards. They increase the resilience of communities by strengthening livelihoods and the availability and quality of drinking water, food supplies and other natural resources. Through the process of urban expansion, cities transform their surrounding environment and often generate new risks. The urbanization of watersheds can modify hydrological regimes and destabilize slopes, increasing hazards such as floods and landslides. Maintaining a balance between human actions and ecosystems is an excellent strategy for reducing risk and contributing to resilience and sustainability.


Raise awareness of the impact of environmental change and degradation of ecosystems on disaster risk

  • Recognize and communicate the multiple functions and services that ecosystems provide to a city, including natural hazard protection or mitigation.
  • Educate the public about the negative consequences of global warming and climate change.

Promote green growth and ecosystem protection in planning for sustainable livelihoods and development

  • Review the environmental consequences of existing plans, policies and programmes; integrate ecosystem considerations into future planning processes and tackle drivers of degradation.
  • Reduce greenhouse gas emissions and promote the transition to a green economy; invest in risk reduction and ecosystem-based measures to adapt to climate change.

Establish alliances with environmental managers and the private sector

  • Build capacity with partners to carry out risk and vulnerability assessments, environmental assessments and scientific monitoring, expanding governance capacities for ecosystem-based disaster risk management through multi-sector, multidisciplinary platforms, involving local stakeholders in decision making.
  • Build partnerships with the private sector to leverage technical and financial resources and ensure that private investments follow environmental and risk reduction norms.

Strengthen existing ecosystem management instruments or establish them where they do not exist

  • Establish a sustainable watershed management programme to balance water needs; protect the ability to capture, store and release water; control sedimentation; maintain downstream flows for environmental needs and mitigate water-related hazards.
  • Incorporate ecosystem-based flood reduction measures into engineered infrastructure to support coastal protection, upstream reforestation, wetland and river bank restoration, and floodplain regulation to achieve urban development goals.

back to top →
  • Hubei Province (China) and New York (United States)

  • Ecosystem-based Disaster Risk Management – Hubei Province, China and New York
    In Hubei Province, China, a wetland restoration programme reconnected lakes to the Yangtze River and rehabilitated 448 km2 of wetlands with a capacity to store up to 285 million m3 of floodwater. The local government subsequently reconnected eight more lakes covering 350 km2. Sluice gates at the lakes are re-opened seasonally and illegal aquaculture facilities have been removed or modified. The local administration has designated lake and marshland areas as natural reserves. In addition to contributing to flood prevention, restored lakes and floodplains have enhanced biodiversity, increased income from fisheries by 20-30% and improved water quality to potable levels.
    Read more in the UNISDR Global Assessment Report, chapter 6.4.

    In New York, untreated storm water and sewage regularly flood the streets because the ageing sewerage system is no longer adequate. After heavy rains, overflowing water flows directly into rivers and streams instead of reaching water treatment plants. In New York City, traditional pipe and tank improvements are estimated to cost US$6.8 billion. Instead, New York City will invest US$5.3 billion in green infrastructure on roofs, streets and sidewalks. This promises multiple benefits. The new green spaces will absorb more rainwater and reduce the burden on the city’s sewage system, air quality is likely to improve, and water and energy costs may fall.
    Read more about these initiatives at:, chapter 6.4.

back to top →
  • Overstrand Municipality (South Africa)

  • Addressing the Increasing Risk of Droughts
    The Overstrand Municipality in South Africa has faced rapid and seasonal population growth and projected shortages of water in the district of Hermanus, where rainfall has declined since 1997. Climate change threatens to bring more variable rainfall patterns and more extreme temperatures. In response, the municipality adopted a comprehensive water resource management and development programme, which draws on the national policy and legislative platform developed by the South African National Department of Water Affairs and Forestry. Seeking a longer-term, multi-stakeholder programme with growing public recognition of drought risk, two strategies were devised: better management of water demand and finding additional, sustainable sources of water. To locate local water sources, groundwater drilling was initiated, after careful analysis of various options. The permanent coordinating role of the local government was vital in conducting such a long-term, multi-stakeholder programme involving national and provincial water agencies, a regional biodiversity conservation institute and a group of community-based organisations. Uncertainty and skepticism among stakeholders regarding the extraction of groundwater was overcome by establishing a participatory monitoring committee and preparing baseline data.
    For more information: (page 52).

back to top →
  • Ecosystem-based management considers the whole ecosystem, including humans and the environment. It focuses on natural environmental units such as watersheds, wetlands or coastal ecosystems (and the human communities that live within them or rely on their resources). It recognizes pressures from societal needs and excesses and seeks to promote patterns of land and resource use that do not undermine the core ecosystem functions and services that city dwellers rely on.