Remembering the Entrustment to Assist in the Ecological Environment Restoration of Erhai Lake - Dali Erhai Lake Project Green Technology Pollution Control and Protection of Mother Lake

In October, by the Erhai Lake in Dali, seaweed flowers, known as the "touchstone of water quality," bloom continuously. In the beautiful scenery of clear water and blue sky, the six sunken reclaimed water plants of the Dali Erhai Lake Circular Wastewater Interception (Phase I) project constructed by China Water Environment Group around Erhai Lake, like a pearl necklace, form a major artery for intercepting and reusing domestic sewage around Erhai Lake, achieving full collection and nearby treatment of domestic sewage, and 100% reuse of reclaimed water. The project has made significant contributions to the continuous improvement of Erhai Lake water quality and fundamental transformation of the ecological environment through the practice of technology pollution control and green development concepts.

Aerial view of Xizhou sunken reclaimed water plant

Recycling and regeneration, building a strong defense line for intercepting pollutants around Erhai Lake

The total area of Erhai Lake Basin is over 2500 square kilometers, with a permanent population of nearly 1 million. In 2023 alone, the number of tourists visiting Dali reached nearly 100 million. In order to cope with the threat of a large amount of production and domestic sewage to the ecological protection of Erhai Lake, the Dali Erhai Lake project follows the concept of circular and renewable energy, and has built a strong pollutant interception defense line around Erhai Lake. Submerged reclaimed water plants reduce the demand for fresh water resources by recycling and reusing wastewater, which is particularly important for cities with water scarcity.

Through sewage purification technology, the Dali Erhai Lake project treats approximately 54000 tons of production and domestic sewage per day, and intercepts over 2000 tons of various organic pollutants annually. As of September 30th, the cumulative treated water volume of the project is 110.579767 million tons. After treatment and purification, some indicators of the regenerated water can meet the Class III water quality standards for surface water.

The project has reduced energy consumption in the sewage treatment process by optimizing the process flow and adopting energy-saving technologies, achieving green and low-carbon operation of sewage treatment. The treated recycled water is not directly discharged into Erhai Lake, but is transported through pipelines for mountain greening, agricultural irrigation, urban sanitation water, and sanitation greening, achieving diversified recycling of water resources.

Double corridor sunken reclaimed water plant tail pond reservoir - Lihuatan ecological pond reservoir

Aerial view of the sunken reclaimed water plant in Wanqiao

Technological innovation, Erhai Lake case helps global ecological civilization construction

In recent years, the ecology and water environment of Erhai Lake have continued to improve, shifting from "one lake governance" to "comprehensive governance" and "ecological governance". The comprehensive governance technology and experience of Erhai Lake have solved the problem of integrating lake ecological comprehensive governance with ecological industries. The "Erhai Lake Case" and "Erhai Lake Experience" have stepped onto the world stage, providing a world model for lake governance.

In September 2022, the Dali Erhai Lake project won the 2022 International Water Association (IWA) Innovation Award from 203 projects in 52 countries worldwide. In June 2023, the Chairman of the Group, Hou Feng, spoke as the only representative of a company at the Global Call 2023 global proposal solicitation event, sharing the innovation and experience of the Erhai Lake governance project with the world and receiving high recognition from the United Nations. In September 2024, the 2024 Forum on Promoting Global Ecological Civilization Construction (Erhai Lake) (European side event) was held in Geneva, Switzerland. The experience of ecological protection and governance of Erhai Lake has been unanimously recognized by on-site personnel, and China and Switzerland have discussed the intention of establishing a friendly lake between Erhai Lake and Lake Geneva.

The Dali Erhai Lake project has solved the problem of integrating lake ecological comprehensive management with ecological industries, turning the process of building ecological civilization into a process of seeking benefits for the people, and paving the way for high-quality and sustainable development of water ecological environment comprehensive management.

Dali Company will bear in mind the earnest instructions of "must protect Erhai Lake well", adhere to the original intention and mission of "not allowing a drop of sewage to flow into Erhai Lake", and guard Erhai Lake before setting off.