A Study On The Five-Year Pilot Project Of "Sponge City"

The flood season is coming again. Recently, many cities have issued thunderstorm warning, a rainstorm, short-term precipitation, "city to see the sea" has become a helpless "landscape.". On the evening of August 9, a rainstorm in Beijing, namely "flooding Sanlitun", has greatly affected people's and cars' travel. However, this does not negate the success of sponge city.

Five years ago, the first batch of sponge city construction pilot list was released. In the past five years, sponge cities have been built in many places. The year 2020 is a "test year" in which more than 20% of the urban built-up area will meet the target requirements in the guidance of the general office of the State Council on promoting the construction of sponge city.

A reporter who was responsible for the city's waterlogging in the 21st century was responsible for a lot of problems, such as the city's water drainage system.

Five years ago, Wu Yuchuan, a Shenzhen water planning and Design Institute Co., Ltd., who participated in the construction of Shenzhen's "sponge city", and who is in charge of the design and treatment of Longgang River Basin in Shenzhen, further told the 21st century economic report that the construction of sponge city is a systematic project, with water ecology, water environment and other aspects. Compared with the traditional engineering planning, sponge city planning focuses on the transit city Instead of a single municipal water management and control system, it is a solution to the problem of municipal construction.

From the perspective of some pilot cities, good results have been achieved in some places. However, there are also reports that some places are still "watching the sea with heavy rain".

In response, Yu Kongjian, vice chairman of the Technical Steering Committee for sponge city construction of the Ministry of housing and urban rural development, told Xinhua that in the past, the pilot scope of "sponge city" was part of the city rather than the whole city, and the construction effect was remarkable. However, in order to thoroughly solve the problem of urban waterlogging, we still need to start from the source, and in a larger scope, we should work with ecological governance of land, ecological water conservancy projects, and ecological management of water conservancy projects Rural sponge and other system governance are combined together to solve the urban flood problem with the concept based on nature.

Lin Hongchao, director of the emergency management law and policy research base of China University of political science and law, also said that the waterlogging problems in many cities are related to the uncoordinated proportion of land planning. "To reduce waterlogging in cities, it is necessary to strengthen the water infiltration capacity in the region, such as increasing the park area, reasonably planning industrial and commercial economic land, and so on."

Five year "quiz"

Sponge city construction has been carried out for many years in developed countries and regions with early urbanization, and has gradually become an important choice of urban construction in the world. Wu Yuchuan told the 21st century economic reporter that the concept of low impact development was proposed in foreign countries in urban construction. On the basis of learning and learning from foreign advanced sponge city construction experience, China formally proposed the concept of "sponge city" at the 2012 "low carbon city and regional development science and Technology Forum".

In October 2015, the general office of the State Council issued the guiding opinions of the general office of the State Council on promoting the construction of sponge city (hereinafter referred to as the opinions), which proposed that through the construction of sponge City, comprehensive measures such as "infiltration, stagnation, storage, purification, utilization and drainage" should be taken to minimize the impact of urban development and construction on the ecological environment, and 70% of rainfall should be absorbed and utilized on site By 2020, more than 20% of the urban built-up area will meet the target requirements; by 2030, more than 80% of the urban built-up area will meet the target requirements.

Wu Yuchuan said that the core of sponge city itself is the absorption and utilization of rainwater, and the above-mentioned six character policy has always been implemented in the construction of Shenzhen sponge city.

According to the 21st century economic report, according to the incomplete statistics of public reports and reports of relevant departments, in addition to the first and second batch of 30 pilot cities previously announced, more than 400 cities have made implementation plans for sponge city construction, all of which follow the urban construction goals of 2020 and 2030 mentioned in the above-mentioned "opinions".

For example, recently, the Department of housing and urban rural development of Guangxi autonomous region issued the implementation plan of Guangxi sponge city construction in 2020, and Guangzhou Zengcheng officially released the special plan for sponge city in Zengcheng district (2019-2035).

At present, the implementation of "sponge city" has achieved certain results Wu Yuchuan pointed out that according to the characteristics of the cities in the 21st century, Wu Yuchuan, according to their own characteristics of the cities, such as Wuhan and Shenzhen, have been promoted to alleviate the economic problems.

Previously, Beijing's standards focused on rainwater utilization and control; Tianjin's standards focused on planning, design and construction; Xiamen's standards focused on construction acceptance and selection of engineering materials; Qingyang City, known as "the first Loess Plateau in the world", focused on solving the problems of rainwater drainage and comprehensive system construction of gully protection, which is conducive to the sustainable ecological development of the whole loess plateau It has typical significance.

However, Wu Yuchuan does not deny that there are still "waterlogging" in the pilot cities, because not all the pilot cities have implemented the "sponge city" construction.

Instead of "replacing the traditional drainage system" with "the traditional drainage system", it does not mean that "the traditional drainage system" can be replaced by "the traditional drainage system". In the process of water supply and drainage, the complexity of water supply and drainage should be considered in the long-term, and the natural circulation and utilization of groundwater should be considered.

Long term systems engineering

In the people's network leadership message board and other platforms, some netizens reported various problems about the construction of sponge city. For example, some netizens reflected that it was still raining "watching the sea" after becoming a "sponge city" pilot project.

In this regard, the relevant departments responded that the above phenomenon was caused by problems such as poor maintenance of permeable materials in the later stage.

Wu Yuchuan also explained to the 21st century economic reporter that not all urban areas of the current pilot cities are included in the pilot construction, and the sponge city construction is a systematic and long-term complex project, including not only construction, but also subsequent operation and maintenance.

In fact, the sustainability of construction can be found in the sponge city construction projects participated by some enterprises. For example, on September 15, 2016, pioneer shares announced that it has participated in the pilot construction project of sponge city in Qingyang City. The main construction contents of this project include: Road Engineering, municipal pipeline engineering, park green space engineering, public construction land and sponge transformation project of old residential areas. The construction period of the project is 2 years and the operation period is 20 years.

Yu Kongjian also said that the sponge city was not built in a day. It may take five years, 10 years or even longer to solve the problem. "We can't say that the pilot project of sponge city has failed because of the flooding this time. All of these cities have a certain role of demonstration. However, the demonstration significance is mostly local. Ecological water conservancy and the construction of land sponge system are the fundamental way out. "

Because of its long-term and long-term nature, the investment is also huge. Chen Zhenggao, former Minister of the Ministry of housing and urban rural development, has publicly disclosed that the investment in sponge city construction is expected to reach 100 million to 150 million yuan per square kilometer. The guiding opinions on promoting the construction of sponge city put forward that government guidance and social participation should be adhered to. We should give full play to the decisive role of the market in the allocation of resources and the government's regulatory and guiding role, increase policy support, and create a good development environment. Actively promote government and social capital cooperation (PPP), franchising and other modes to attract social capital to participate in sponge city construction.

For example, the sponge city constructed by the above-mentioned pioneering shares is operated in accordance with the PPP mode.

However, Yu Kongjian also pointed out in an interview with the media that PPP mode is well used in infrastructure, such as sewage treatment projects. Every year, the part of the government's public investment is returned to investors in the form of purchasing services. This aspect is very mature. However, it is difficult to calculate public services in sponge cities with PPP mode, because sponge cities are equivalent to construction There is no perfect calculation model for an ecological green space system.

At present, the government does not have the ability to pay for rainwater in the 21st century. However, the government does not have the ability to pay for rainwater in the 21st century Due to the influence of payment situation, enterprises give up participating in the competition of PPP projects in some sponge cities.

At the same time, in the process of sponge city construction, the old facilities need to be transformed, and some people point out that such investment will cause waste. In this regard, Wu Yuchuan analyzed the experience of Shenzhen sponge city construction to the 21st century economic reporter. At present, many cities integrate the construction content of sponge city with engineering construction. For example, the permeable brick with strong permeability is directly used in the floor tile, and it is also integrated into the urban sponge when greening design.

"At present, in the construction of sponge city in Shenzhen, green measures such as planting ditches, permeable bricks and sunken green space are used to organize the planning and design of drainage, which not only avoids flooding, but also effectively collects rainwater." Wu Yuchuan said that the construction of sponge city is not achieved overnight, but requires more long-term projects with comprehensive design.