Stormwater Harvesting and Trades in a Sponge City

China CCTV
Published: 26 September 2022
Last edited: 26 September 2022
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Summary

In the Changsha City of Hunan Providence, China's first stormwater trade agreement was successfully launched and implemented thanks to the support and collaboration between government agencies and several private parties.  

 

On September 24, 2020, Changsha High-tech Zone Municipal Garden Sanitation Co., Ltd. and Hunan Yuchuang Environmental Protection Engineering Co., Ltd.(Yuchuang) signed a strategic agreement to buy and sell harvested stormwater resources in some Sponge City communities, creating a new model of the utilization of stormwater and supporting the sustainability of Sponge City implementation. 

 

Harvested stormwater in selected Sponge City facilities can be sold at a price 20% lower than the local tap water price, creating an incentive for stormwater harvesting and reuse.  The stormwater is later used in landscaping irrigation, waterscape supplementation, dust control, etc.

 

 

Classifications

Region
East Asia
Scale of implementation
Local
Ecosystem
Area-wide development
Buildings and facilities
Green spaces (parks, gardens, urban forests)
Urban ecosystem and build environment
Theme
Infrastructure maintenance
Outreach & communications
Sustainable financing
Water provision and management
Watershed management
One Health
Water, sanitation and hygiene
Urban and Disaster Risk Management
City management, governance and finance
Sustainable urban infrastructure and services
Challenges
Drought
Erratic rainfall
Floods
Storm surges
Inefficient management of financial resources
Infrastructure development
Lack of access to long-term funding
Lack of alternative income opportunities
Lack of infrastructure
Sustainable development goals
SDG 6 – Clean water and sanitation
SDG 11 – Sustainable cities and communities
Sendai Framework
Target 3: Reduce direct disaster economic loss in relation to GDP by 2030

Location

Changsha, Hunan, People's Republic of China

Challenges

The long-term funding stream for Sponge City is very crucial. Since most private sectors lack interest in investing in Sponge City projects, and stormwater fees are also far from being implemented in most cities in China.  Other funding sources for Sponge City implementation are needed to support the construction and O&M.  

 

The current stormwater trading system is still on a pilot scale.  One major challenge is that water and stormwater rights are still not clear in China.  Thus the trading system in its current format is still more government-mandated than market-driven, which needs to be improved in the near future. 

Beneficiaries

1) Property Owner:

Gain 0.7 yuan (US$0.11) per cubic meter of rainwater;

2) Yuchuang: 

Sell after a good markup at 3.85 yuan (US$0.60), 

3) Landscaping Company:

The price is still 20 percent cheaper than the tap water price, a good cost-saving.

 

How do the building blocks interact?

Experts in water trade, water resources management, and stormwater management were invited and served on a technical committee to educate the representatives of all parties, as well as conduct educational events for the residences.  We learned that communications during outreach and collaboration are important to bring people with different backgrounds together to reach a win-win agreement.

 

 

Impacts

The goal of Sponge City, which is required by the Chinese government,  is to manage and retain approximately 70% of the stormwater runoff in 80% of urban lands by 2030. This creates a good opportunity to reuse the stormwater and sell excessive water resources to other parties.

 

Since 2014, the harvested rainwater of Yuchuang can reach 1 million to 2 million cubic meters per year, and its value can be up to 1.5 million yuan (0.21 million US$).  This actually only accounts for a very small portion of total rainwater resources in Changsha City.  

 

It was the first in China that the rainwater can be traded on a state-run exchange, as a small step toward reallocating water resources to solve its water crisis.

Contributed by

yumingsu_41730's picture

Yuming Su American Academy of Water Resources Engineers, State Key Laboratory of Silica Sand Utilization, Changsha Sponge City Eco-Industry Technology Innovation Strategic Alliance

Other contributors

CSEC -Changsha Sponge City Eco-Industry Technology Innovation Strategic Alliance