In the past May, Beijing ZEHO Waterfront Ecological Environment Treatment Co., Ltd. (ZEHO ECO) successfully won the bid for the EPC project of Nansihu Lake Basin Fengpei Canal Ecological Restoration and Improvement Project (Qing Section). Following the Qin Section, ZEHO ECO once again undertook the ecological restoration and improvement of the Fengpei Canal. At present, the Qin Section project has entered the ultimate phase, and the construction of the Qing section is in full swing. How does ZEHO ECO made the Fengpei Canal green and beautiful? We invited design director Zhang Chengliang, water ecology director Cao Zhe, project manager Zou Honghao, and business manager of the client (Peixian County Xingtian Group) Cai Chengsong, to share their innovative design concepts and the approaches for high-quality construction.
Zhang Chengliang (top left), Cao Zhe (top right), Zou Honghao (bottom left), Cai Chengsong (bottom right)
Q1: What was your impression when you first took over the project?
Zhang Chengliang: I still remember the first time I walked up the road to the top of the embankment through the dirty river bank, wearing a mask, stepping on the blanket of white poplar catkins, and looking at the lush and tall poplar trees, I could hardly find other tree species. I know what the key to design is: ecological restoration and water quality are the top priorities. But I kept asking myself: Is that all? How can we integrate multiple opinions and multi-professional appeals from the standpoint of overall design?
Hard embankment before ecological restoration
Cao Zhe: As the last ecological barrier to the Nansihu Lake, the ecological environment of the Fengpei Canal is closely related to the water quality safety of the Nansihu Lake and the East Route of the South to North Water Transfer Project. In the communication with the government stakeholder, I also thought step by step about what is most needed by the Fengpei Canal. I remember one meeting with the leaders of the County Party Committee and the County Government that impressed me most: “The ecological restoration of the Fengpei Canal is to improve the water environment quality and biodiversity, not to build a landscape.”. This sentence also makes me more confident to the ecological environment design.
Zou Honghao: At the beginning of the project, I found that there were poplar forests on both sides of the river, which sprouted late in spring, fell leaves early in autumn, and was bleak in winter, lacking color change. And the plant structure is lacking diversity. The richness of the plant species, the biodiversity, the ability of rainwater filtration, and pollutant interception is low. Many poplars fly catkins seriously in spring, which will fall into the river and pollute the river. From the perspective of landscape, ecology and livability, we have a lot of work to be done.
Cai Chengsong: In the middle of 2021, the Group appointed me to assist the Fengpei Canal Project. I am a citizen of Peixian County. I feel energetic to witness the implementation of this livelihood project for the benefit of the party.
Before ecological restoration of Fengpei Canal in Nansihu Lake Basin
Q2: How do you and your colleagues plan and implement the project in the process of work?
Zhang Chengliang: We have determined the design guideline of “blue, green, gray and red”, which is also the ZEHO ECO’s design principle for the corridor. In the Peixian County project, the four dimensions of water quality stability, ecological restoration, popular science experience and cultural immersion were integrated. The ecological team applied the Nature-based Solutions and the technical approaches of “point surface” in combination with 8 types of purified wetlands and 4 types of four-dimensional ecological buffer zones, “water, bank, beach, levee” ecological construction method cascade, etc., to build a variety of habitats while implementing the terminal interception and purification of pollutants, improving the guarantee rate of river water quality, and realizing the restoration of site biodiversity. The planning team would plan the project positioning and consider how the planned activities can drive the surrounding vitality and form linkage benefits. They would also consider how people can easily come to the river and how to drive the development of surrounding plots. The ecological landscape team made the overall concept implemented, so that people can feel the multi-dimensional interaction of ecology, landscape, poetry and culture in the blue and green nature. We hope that this place will become the home of every life and find its own space.
Ecological level of water, bank, beach and embankment
Cao Zhe: Since joining ZEHO ECO in 2018, many projects including subsurface purification wetlands, waterfront river treatment, sponge city design, and watershed ecological restoration, have made up for some deficiencies in my past work experience and enriched my professional ability. In the ecological restoration and improvement project of the Fengpei Canal, we adopted a series of technologies such as multiple types of purified wetlands, four-dimensional ecological buffer zones, near natural forest land restoration, ecological construction methods, and habitat construction to build a Weishan Lake ecological corridor with ecological buffer, pollutant interception and purification, natural work, and natural succession.
Zou Honghao: In this project, ecological revetment was adopted, reducing the application of hard revetment. Seven ecological construction methods were adopted for revetment, including wooden pile revetment, natural vegetation revetment, multi-stage aquatic plant revetment, three-dimensional vegetation net vegetation revetment, plant cutting revetment, cutting dormancy revetment and gabion revetment. In combination with engineering technology and biological characteristics, the soil fixation effect of plant roots and plant buffering and interception capacity were used to stabilize and strengthen the slope and improve the anti scouring performance, which not only increased the number of riparian plants, It could also create a good living environment and formed a natural ecological revetment.
Ecological revetment based on local conditions
Cai Chengsong: I usually spent most of my time on the construction site. I should control the progress and details of the project on site, and also preside over various project meetings, such as coordination, regular meetings, inspection, etc. From the start to the end of the project, the constructors and designers went to work early and returned late every day, and there was no rest from Monday to Sunday. Only working hard without complaining can we do an excellent project.
Project site control project progress and details
Q3: What were your most impressive moments in the process of project implementation?
Zhang Chengliang: It’s hard to protect the existing seedlings. At the beginning of the construction, we adhered to the construction principle of “reserving the existing forest land of the levee as much as possible, thinning and clearing appropriately to replace tree species, and increasing biodiversity”, and protected the original tree species in the site as much as possible. During the construction, we often encountered that the garden road needed to pass through the existing poplar trees. In order to protect the existing seedlings, we would try to design the road pass through the trees. Although it would cause difficulties in material transportation, machinery construction, construction difficulty and high cost, we still adhered to the principle of building the garden road among the trees by secondary transportation and manual work.
Cao Zhe: The entire process was very impressive. The weekly round of multi-professional design brainstorming often went on late at night, or even overnight. Every technical guidance, plan sketches drawn by the British designer, technical supervision on construction site, discussion and even debate on a technical detail and a construction method are all fresh memories.
Brainstorming in the late night
Technical guidance of British designers
Zou Honghao: In order to enable the project to be implemented as soon as possible and completed on schedule, all the management personnel of the project department work overtime, give up the rest on holidays and stick to the construction site. In the project, most of the managers did not take a day off for three or four months, and almost worked overtime every day. All the management personnel of the project had a common goal of “thinking together and working together” - ensuring quality and quantity, delivering on time, and giving a satisfactory answer to the client and Peixian County.
All management stuff of the project work overtime to stick to the project site
Cai Chengsong: At the beginning of the year, when Peixian County TV interviewed you. When I was asked how the project was successful and continued, I said that the project construction should take the lead. Daily report system shall be adopted for project management, and the project site progress shall be dispatched and rechecked in time every day. The most recent Qin Section also completed the smooth connection to the Qing Section of the second phase as scheduled. My expectations for the project are also increasing, and I am more energetic.
Q4: After the project is completed, what changes do you want people to focus on most?
Zhang Chengliang: I want people to pay attention to our ecological position. An extensive area of hard concrete on the site, which we insisted on demolishing and cleaning, remained in the site to form a stone beach, which stopped the continuous runoff pollution of the hard ground and expanded the purification wetland. It provides children with a stone beach paradise in the grass. When the river rises, they may find bugs under the rocks. On a quiet summer night, frogs in the shallow water will climb up the stony beach and play music.
Stone beach formed by concrete recycling
Purified wetland
Cao Zhe: As an ecological project, we have also made a lot of efforts on recycling. For example, the ground is paved with granite stone instead of natural volcanic stone, which has natural holes. Surface water infiltration can supplement groundwater resources. In addition, the remaining volcanic rock leftovers are not discarded, but recycled. They are placed in gabion benches to replace some pebbles, fully reflecting the ecological and environmental protection of the project.
Volcanic rock stone pavement and gabion stool
Zou Honghao: In the past, there were poplar trees on both sides of the river. In spring, poplar catkins flew all over the sky. I heard people hated coming here, so I didn’t think it was interesting. Recently, a nearby villager said to me, “Now the surrounding environment is good, and people have a good place to walk”. I think the “popularity” brought by good construction is a major change here.
It's a good place for people to walk
Cai Chengsong: The project site has changed from a desolate dock to an online celebrity ecological card punching site, which not only provides a beautiful and livable living environment for local people but also enhances the people’s awareness of ecological environment protection. Such a project is a real livelihood project, benefiting one party. I think it is worth paying attention to.
Blue green coupling, natural succession, and Fengpei Canals is growing