The Tangshan Quarry Park is a project to rejuvenate an abandoned quarry into a dynamic public space. Facing the given condition of three large quarry craters and severely damaged ecosystem around the quarry, our design response is to create an experience-based park that integrates the community and restores the integrity of the ecosystem. It is to transform the industrial relic to a park that heals the nature and serves the public.
The project is located 30 km from the center of Nanjing City and on the southside of the Tangshan mountain. The quarry formerly known as the Longquan Quarry was the largest limestone mine in the region. The quarry was in operation from 1990 to 2004. 15 years of mining left 3 gigantic craters in the southside of the Tangshan mountain. Since 2017, the local government has been collaborating with a team of landscape architects, mountain maintenance engineers and soil ecologists to rejuvenate the abandoned quarry and vicinity area. To restore the damaged ecosystem has been the main goal and approach of this effort.
The project covers an area of approximately 40 hectares. The elevation changes on the site vary from 160 to 820 feet. From west to east, the biggest elevation change of the craters is 652 feet. Based on the survey, some rock walls were in the danger of falling and collapsing. The ecological condition of the mountain body outside of the 3 craters and above 300 feet elevation was considered good. This area provided relatively better habitat of most of local plants and animals. The ecological value and sensitivity were at high level. For the area below the elevation of 300 feet, the terrain was gentle. In this area, the human activities were heavy, the ecological value and sensitivity were at low level. The prolonged industrial activities on the site had polluted the water and soil severely. The level of the heavy metal found in the ground water was high. The soil was heavily compacted and mixed with rocks and muck, which offered very poor condition for plant’s growth. The mining activity also damaged the biodiversity of the area.
• Incorporating the given terrain and functional regeneration. Comparing to the approach to fully repair the rock walls of the quarry craters, we took an alternative to repair the rock walls selectively and strategically. After the detailed evaluation of the rock walls, we sorted the walls into two categories – to repair and to preserve. The preserved rock walls became education opportunities that offer the first hand and close up experience of the erosion of the mountain caused by mining. After careful evaluation of three key factors of the craters – safety, ecological condition and terrain, we selected two craters to introduce human activities throughout the craters. As the decade of heavy mining activities had broken down the mountain and made the then cohesive ecosystem fragmental, we re-organized the vicinity and introduced a series of experience-based activities based on what the individual area could offer.
• Water system management: A system was designed to manage the water in the park. The system utilizes the terrain of the site. First, the run-off water from the high points in the mountain will be retained in the reservoirs at the bottom of the crater; as the water in the reservoirs moves downstream, the water runs through bioretention swale. The bioretention swale helps to reduce the run-off, filter the pollutants, and control the passage of the water. The swale is designed as a system with multiple nods, which enables the detailed management of the water and increases the efficiency of filtration. All water will be gathered in the pond for the final cleaning process. Finally, the quality of the water could reach to the quality of ground water Category 3.
• Restoration of the soil: The task included 1) to restore the bare rock walls; 2) to stabilize the rock walls in danger of falling and collapsing; 3) to preserve selected rock walls as the illustration. The sapropel from the existing natural pond was transferred to the large scaled grass field on the mountainside as fertilizer. 200,000 cubic yards of sapropel was used to restore 155,000 cubic yards wild flower bed. The transformation sustained the water ecosystem and the soil repairing in the park.
• To preserve the biodiversity: One of the main goals of the project is to increase and sustain the biodiversity and to restore the ecosystem on the site. In order to achieve the goal, the project employed three strategies – 1) to control the invasive species; 2) to restore the native species; and 3) to protect the endangered species.
• Encouraging recreational programs and outdoor education: former stockyard of the quarry was transformed into a playground to tell the story of the site history. It is a popular destination for families and school field trip.
• Selection of the materials: Locality, low maintenance and low cost are the principles of the design based upon. For example, the designed specified the rocks for the construction should be found on site with little to no processing requirement needed.
Sustainable operation and maintenance
For the past 5 years, the ecological condition in the quarry has improved significantly. The living condition of the native flora and fauna has been protected and improved. The project offers an outdoor experience based on recreation and education to the locals and tourists. In addition, the Park took a different path from many projects with similar background that were only to propel the land value for the real estate development. The Tangshan Quarry Park has satisfied the purposes of to restore the ecology, and to sustain the operation financially and socially. It has set an example for the future sustainable development of such public realm.
Location: Nanjing, China, 32.0398938, 119.0364994
Design year: 06, 2017
Year Completed: 03, 2019