-
Architects: NODE Achitecture & Urbanism
- Area: 34160 m²
- Year: 2021
-
Photographs:Chao Zhang
-
Lead Architect: Doreen Heng Liu
Background and History. 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 flock. 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 Shenzhen citizen
To tackle the much-concerned water environment problems, the city released Shenzhen Water Control and Quality Improvement Work Plan (2015-2020) 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 newly built 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 resulting from the urban renewal and development in Qingshui River - Sungang Area. 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 we 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, we 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. Though we were engaged to only provide SD for the surface landscape improvement in the Project, we 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 the surface flood control requirements. On this basis, we 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 as a buffer for flood discharge. To ensure water safety, it was fundamental to tackle the existing site elevation and design ones with due care. For example, the lowest elevation of the vent shaft door and window opening out of the ground must reach 100-year flood is 12.4 m; The evacuation staircase exits and supporting office buildings must reach 200-year flood is 13.4 m.
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 we were 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 underground 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 also the unique feature of the Project and one of the most important challenges facing the surface landscape restoration design.
Claims of Different Stakeholders. In addition to the above water-related design challenges, we were also faced with various claims from different stakeholders (such as the government, the park authority, and Operator）as we 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 island(s) 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, may change people’s stereotype about “sewage plant”. In our opinion, these are typical issues encountered in the design process of many urban projects. Design is always "on the way", and we should always keep a "change-embracing" mindset towards various requirements in different stages, to ensure that the "on-the-way" design will not affect the overall progress of construction; but for us, the biggest challenge was to ensure the original intention and the final completeness of the design in a continuous "changing" process.
Water Landscape - Infrastructure Publicization. As mentioned above, our SD 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 our own design ideas. We should not only restore the park landscape, but also create a new public landscape area that is different from any conventional landscape-only design and realize the project goals in terms of mixed-use functions, aesthetic pursuit, public education and diversified and multi-level experience.
Strategy and Design Approach. Given the above requirements and challenges, it is critical to focus on the core issue, i.e. the interface between engineering design and space design.
Art Installation Treatment and Publicization of Infrastructure. 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 contract with the ecological environment of the park. The park management encouraged us to extract historical symbols from the Lingnan gardens of the former Honghu Park and use them as ornamental elements. But we must 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. This was an issue about values and design. We 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. Then we incorporated the cultural and natural characteristics based on the landscape and vegetation characteristics and tried to dissolve the stereotype of the infrastructure resulting from overemphasized engineering features.
For example, the highest deodorizing vent shaft was nealy16 m above the ground, and we naturally made it a 3D abstraction of lotus, the theme plant repeatedly emphasized by the park management, and a public art installation. 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 lotus landmark in Honghu Park.
The six medium-sized vent shafts containing evacuation stairs were designed with accessible paths and platforms, reflecting different characteristics in spatial form. The six small ones were dedicated for ventilation, so only facade greening on grilles of similar materials were employed to enhance the natural feel, including a rain shelter with seats. During the whole design process, we’ve been trying to avoid excessive design despite of many unexpected factors “informed” about the underground works. We neither highlight nor cover-up, but instead, we made the best out of the project conditions to achieve natural unity and harmony.
Underground Supporting Building: Explicit and Implicit Presentation of Gardens. The northernmost underground supporting building was planned as office space. As it stood at the end of the Park, geographically out of the way, how to create enough magnets to guide the public to discover and walk to it became a key design issue. In response, we adopted a design strategy that emphasizes both software and hardware. On the one hand, we 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 open garden; on the other hand, we tried to create a distinctive public space and garden on the ground level as the landscape highlight and the pre-function zone of the exhibition hall to attract people. Here, we extended the gardening concept. With reference to the contemporary formal language and constructional forms, we arranged the basic and explicit spatial elements of “pavilion and corridor” around the the underground open 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.
Conclusions and Reflections. The project lasted four years from the commencement of our surface landscape design to the project completion, during which we witnessed the joining of stakeholders at a different stage, their claims, major design revisions, back and forth in CD drawings, and at the construction stage. Though the project was eventually recognized by stakeholders, there were still many regrets. If the stakeholders could just join the project at the early stage at the same time, and reach consensus on production processes, the cross-over and methodology of architecture and landscape, and the common standards for specialized design and construction quality, infrastructure publicization projects 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, we hope that, through the active design efforts of landscape architects/architects, the water purification facilities that are indispensible for our daily life will become pleasant and ceremonial places in the city for public experience and learning, thus redefine the significance of infrastructure from the dimensions of spirit and landscape/architectural aesthetics.
