Page 62 - Demo Faces

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NATURE-BASED
INFRASTRUCTURE
Project name:
Project number 42285 – 013, Loan CAM-3311/8295 Grant CAM-0454, Integrated Urban Environmental Management in the Tonle Sap Basin
Project number 47274 – 003, Loan VIE-3590/3591, Grant VIE-0549/0550, TA-9417, Secondary Green Cities Development Project (SGCDP)
Year (of approval):
2017 (both)
Funding:
ADB ordinary capital resources, ADB Strategic Climate Fund, Global Environment Facility (GEF), Urban Climate Change Resilience Trust Fund under the Urban Financing Partnership Facility (UCCRTF)
Modality:
Grant/Loan
Department:
SERD
Sector:
Urban Development (SEUW)
Team:
Sameer Kamal
Satoshi Ishii
Alexander Nash
Okju Jeong (UCCRTF) Cao Hang
Virginia Villanueva Maricar Barrogo Javier Coloma Brotons Pham Quang Tien Thuy Trang Dang
CHALLENGE:
The classic urban development problems in Cambodia and Viet Nam
Wastewater treatment
Stormwater drainage
SOLUTION
Flood protection
The methods used to solve them are new, seeking to make use of natural processes and assets where possible to improve sustainability
Nature-based wastewater treatment system
in Cambodia
Concrete channels and embankments
Stormwater runo
mitigated by absorbing surfaces rather than traditional impermeable concrete or bitumen
Replace with
Water sensitive design for flood protection and water quality improvements
in Viet Nam
Natural water courses and natural edge
Drains are permeable and planted, allowing water to be retained, absorbed, and transpired
Retention basins
are permeable and act like sponges
Retain the natural, pre-urbanization characteristics of the watershed
Slow down flow accumulation and lower peak discharge rates.
Lowers infrastructure capacity requirements
The principle
Improve water quality using nature-based treatment processes, such as filtering biotopes
Provide access to water: a key step in generating demand for clean water and a clean environment
Water quality
To convince
decision makers and engineers of the merits and security
NEXT STEPS
Developing robust empirically supported design standards with adequate safety margins
Clarity on unit capital costs (for estimating, for bills of quantity), suppliers and operating costs
Demonstrate the economic benefits
Lower cost