Tongjian Lake, located in Shuangpu Town of Hangzhou, is historically the sister lake to the famous West Lake. Positioned at the convergence of the Qiantang, Fuchun, and Puyang Rivers, it was a key ferry point in southern Hangzhou and a significant cultural hub during the Southern Song Dynasty. Over time, sediment from the Qiantang River and land reclamation projects caused the lake's waters to recede. This led to local water shortages, flooding problems, and a fragile ecosystem. 

The project's challenge was to improve flood control while enhancing water quality, ecology, landscape, and regional cultural-economic revitalization.

To meet the water planning requirements of 5 million cubic meters of total storage and 3.2 million cubic meters of regulated storage, the design team integrated factors like historical lake morphology, site spatial pattern, landscape resources, and transportation systems. They aimed to restore the historical 2 square kilometer surface area of Tongjian Lake, strategically laying out 859,700 square meters of deep water areas, 732,200 square meters of shallow water areas, and 408,100 square meters of islands.

The design team drew upon the site's natural elements - lakes, mountains, fields, tea, and grass - to rebuild the blue-green infrastructure and restore habitats. By integrating wetlands, islands, revetments, and gentle slopes, they fostered diverse ecological communities, enhancing species biodiversity. They also employed cultural heritage assessment methods to identify and organize existing relics, creating conservation areas. These historical memories were embedded into landscape focal points like the ancient lake port, which highlighted the site's history.

The ecological water management project of Tongjian Lake has reconnected the city, nature, and its inhabitants. Led by landscape designers, the urban water hub project improved water circulation and raised water quality from Class V to Class III standards. It also met the 20-year return period standard for flood control.

The water quality in the region and the central lake area has been significantly improved. The establishment of terrestrial and aquatic plant communities in the lake area is refined, significantly improving the ecological environment and substantially raising the biodiversity index. The latest survey revealed the addition of 10 bird species, including nationally protected species such as Hydrophasianus chirurgus and Fulica atra.

The project has spurred sustainable development in the region. It mobilized 250 million yuan in private investments and provided jobs for over 800 people. Additionally, it attracted 300 local talents to return to their hometown and secured investment agreements totaling 5 billion yuan. Furthermore, Tongjian Lake Park has hosted numerous large-scale events like walking tours, marathons, and cultural performances. Local residents have formed running clubs, and the park has organized over a hundred running and walking activities.

Tongjian Lake once vanished, but it has now re-emerged as a renowned lake. It has become a sought-after destination for various activities like embracing nature, experiencing culture, camping, and gathering. The Ecological Water Conservancy Project at Tongjian Lake exemplifies landscape design, demonstrating a harmonious balance in hydrology, ecology, economy, culture, and public interest.