Shenzhen Lotus Water Culture Base

The project is located at the northern end of Honghu Park, Luohu District, Shenzhen City, south of Nigang East Road and east of Buji River. Honghu Park is a lotus-themed municipal park known for its bald cypress forest and white egret flocks. Completed and opened in 1985, it is not only one of the earliest parks built after the establishment of Shenzhen Special Economic Zone, but also one of the most important urban parks in the eyes of the citizens.

To tackle the water environment problems, the city released Shenzhen Water Control and Quality Improvement Work Plan was released in 2015, which proposed an investment of CNY 81.6 billion on improvement of water environment, including construction and expansion of 19 sewage treatment plants, improvement of 24 ones, and accelerated river improvement initiatives. The Honghu Park Water Purification Plant, one of the key projects for water pollution control under the Work Plan, employs a leading fully buried water purification technology and involves the restoration of the surface landscape of about 3.24 ha. It aims to effectively alleviate the sewage increase problems in Qingshui River resulting from the urban renewal and development. Upon completion, the facility can treat and purify about 18 million m³ of domestic sewage for the surrounding areas every year, an equivalent of about 1.3 times the water volume of the West Lake in Hangzhou.

When NODE Architecture & Urbanism joined the project team, the general contracting designer had completed the design and construction drawings of the underground water purification plant, and everything had been ready for construction. In this project, they were asked to design the restored surface landscape on top of the water purification facility, and the underground offices at the northern end.

Design challenges

They had to achieve sufficient understanding and conduct necessary research about the technical logic and production process/logic behind the landscape design, as the surface landscape is closely related to the underground facility and to the surface flood control requirements. On this basis, they intended to go beyond the engineering logic and tried to create an aesthetic and community-friendly public space.

Water safety

In the flood season every year, the water level of Buji River west of the site rises. When the water level reaches a certain height, the river water will flow into Honghu Lake where a flood storage area is formed to alleviate the water level rise in the flood season. As the site is low land that falls within the flood discharge passage, the final flood control safety assessment of the Project determined that the site elevation for a 100-year flood is 12.4 m and that for a 200-year flood is 13.4 m. In this case, the site landscape needed improvement while meeting the requirement on flood discharge passage. To ensure water safety, it was fundamental to tackle the existing site elevation.

Water treatment

Honghu Lake Water Treatment Plant on a 1.67 ha site was to be built in two phases. The technical part for water treatment is a fully buried double-layer frame structure, with the water treatment capacity of 50,000 m3 and 100,000 m3 per day in Phase I and long term respectively. The main indices shall meet the requirements of quasi class IV water body in the Standard for Environmental Quality of Surface Water. The treated effluent is used to supplement the water in the ecological landscape of Honghu Park and Buji River. The design for this part had been fully completed by the general contracting designer before NODE Architecture & Urbanism was brought aboard. In fact, the fully buried building inevitably brought issues that need no special attention in the case of surface buildings, such as the forms of the visible above-grade part of the ventilation and fire control facilities, which were the focus of design. The original intention of buried facilities for “deindustrialization” was actually presented and brought into reality in another form. This was an unique feature of the project and one of the most important challenges facing the surface landscape design.

Claims of different stakeholders

In addition to the above water-related design challenges, they were also faced with various claims from different stakeholders (such as the government, the park authority, and operator) as they started our designs, due to the park’s importance and much attention it had attracted. For example, the government required that the greening rate of the ground should be restored to 86%, the wetland planning be followed and the relationship between the original ecological bird islands and the landscape be well balanced under the sponge city concept. The park management needed nearly 7,000 m2 as a lotus nursery cultivation base and the restoration of the natural lake shoreline and nearly 5,000 m2 of the water body. The operators aspired for creating a “deindustrialized” wild landscape which, coupled with public science visits, could change people’s stereotype about sewage plants. In their opinion, these are typical issues encountered in the design process of many urban projects. Design is always “on the way”, and it’s important to always keep a “change-embracing” mindset.

Water landscape

As mentioned above, the design needed to, on one hand, streamline the technical difficulties or normative preconditions brought by underground production infrastructure and, on the other hand, incorporate the spatial demands of different stakeholders in different stages, the site conditions, and the design ideas. They had to not only restore the park landscape, but also create a new public landscape area that was different from any conventional design and realize the project goals in terms of mixed-use functions, aesthetic pursuit, public education and diversified multi-level experience.

Art installation

The engineering design of the two-floor underground water treatment plant undoubtedly posed challenges different from those faced by surface buildings in terms of fire protection, drainage, etc. In particular, thirteen vent shafts (some containing fire evacuation stairs) of different sizes and heights protruded out of the ground level, an inharmonious contact with the ecological environment of the park. The park management encouraged to extract historical symbols from the Lingnan gardens of the Honghu Park and use them as ornamental elements. But they had to figure out whether ornaments were simple “addition of symbols”, or they could be transformed at a deeper level in terms of space, material, and shape in combination with the concepts of public experience, natural education, etc. They conducted some design research on “element” extraction from the original spaces of the pagodas, pavilions, gazebos and corridors of Lingnan gardens, and transformed and expressed them with contemporary design languages and materials.

For example, the highest vent shaft was nealy16 m above the ground, and they made it a 3D abstraction of lotus, the plant repeatedly emphasized by the park management. The bird watching and observation platform helped eliminate the compulsory but visually awkward vent shafts and evacuation stairs, injecting useful experience in them and creating an important landmark in Honghu Park.

Underground supporting building: explicit and implicit presentation of gardens

The northernmost underground building was planned as office space. As it stood at the end of the Park, geographically out of the way, how to create enough attractors to guide the public to discover and walk to it became a key design issue. On the one hand, they added the functions of public education and science popularization on top of office function, such as creating a water purification exhibition hall in combination with the underground garden; on the other hand, we tried to create a distinctive public space and garden on the ground level as the landscape highlight. Here, they extended the gardening concept. With reference to the contemporary formal language and constructional forms, they arranged the basic and explicit spatial elements of “pavilion and corridor” around the the underground garden and connected them with circulations to the underground public exhibition halls and office spaces. This approach, both a tribute to the classic precedents and a proper innovation, helped create a secluded, quiet, and slightly mysterious surface garden.

The project lasted four years from the commencement of our surface landscape design to the project completion, during which they witnessed the joining of stakeholders at a different stage, their claims, major design revisions. Though the project was eventually recognized by stakeholders, there were still many regrets. If the stakeholders could have joined the project at the early stage at the same time, and reach consensus on production processes, the methodology of architecture and landscape, and the common standards for specialized design and construction quality, an infrastructure publicization project like this could have been advanced step by step and implemented properly with satisfactory completion degree of key nodes. However, for such infrastructure projects posing major engineering and aesthetic challenges, the consensus and cooperation among different disciplines and professional practices cannot be reached overnight. In fact, there is still a long way for us to go, and all stakeholders need to work together toward this goal.

Upon its completion, the project was renamed Shenzhen Lotus Water Culture Base. It represents another important attempt of the NODE team in infrastructure publicization projects over the years, in terms of interdisciplinary design practice of water purification and landscape architecture. As always, they hope that, through the active design efforts of landscape architects/architects, the water purification facilities that are indispensible for daily life, will become pleasant places in the city, thus redefining the significance of infrastructure.