Zao River is one of the “Eight Rivers of Chang’an” described in Chinese historical literature. After Jue River diverted, Zao River became a river without a source and the status in the “Eight Rivers” was replaced by Jue River. In that case, Zao River assumed the responsibility of sewage and flood discharge in the southern, western and northern suburbs of Xi’an. The long-term discharge of industrial wastewater and domestic sewage has gradually deteriorated the water quality of Zao River, and the river ecosystem has also been greatly damaged. At the same time, with the development and construction of the city, the urban area of Zao River is gradually covered by urban roads, road green belts, buildings, etc., becoming an underground river. The river is heavily silted, and the pollution is prominent.
In November 2018, the Central Ecological and Environmental Protection Supervision Group pointed out that the black-odorous water of Zao River has been covered up and the construction of the sewage removal pipeline in Chang’an section has been perfunctory response. In March 2019, the Implementation Plan of Zao River Three-Year Special Regulation Plan (2018-2020) was officially issued, which aims to carry out systematic and comprehensive improvement of Zao River.
According to the existing problems and site characteristics, the Chang’an section of Zao River is divided into three parts. The upstream section is close to the source, and the surrounding areas are mostly villages and towns. The current situation of the river is a dry hard drainage canal, with disorderly growth of vegetation on both sides and a single landscape. The urban section is in the old urban district where the river has been encroached upon by urban construction, the road is narrow and there is no space for public activities. In the downstream section, the pollution of the water is severe due to sewage discharge, which has affected the surrounding residents. The negative treatment method can no longer hide the seriousness of the problem. How should this ancient river that has witnessed the dynasty change of Xi’an adapt to the development of a modern city and reintegrate into people’s lives?
This plan will make overall plans for the river corridor system, greenway system and plant habitat system, balance the layout of parks and green spaces. Expand green space and build urban ecological corridors and ecological experience areas through revetment renovation, urban greening and other measures, forming the urban green ecological network. Create a CEAD (Central Ecological Active District) that integrates ecological conservation, cultural heritage, closeness to nature, strolling and leisure, and create a new landmark for the future development of Chang’an District.
The surrounding land of the downstream section is mostly residential communities and schools. The main renovation measures for this section are to remove the cover plate, dismantle the original revetment of masonry, widen the river channel and transform it into a variety of ecological duplex sections. Combined with the design of multi-layer steps, water playing squares and stages, make it being a dynamic area where citizens can participate and interact.
In order to meet the needs of parent-child activities, the planning and design of the 100-meter green belt, water area, and children playground provide the surrounding communities with outdoor family leisure and interactive communication spaces, which also provide an urban public space with broad vision, beautiful landscape and complete facilities.
The comprehensive river regulation of Zao River Chang’an section is a systematic solution that put forward by multi-professional collaboration and cooperation. It is to build a multi-level blue-green infrastructure serving urban citizens through the reconstruction of the river corridor ecosystem. Through the overall planning of landscape design, this project integrates the reuse of rain and flood resources, ecological flood control technology, water ecological restoration technology, etc., and builds the Zao River Chang’an section into a demonstration area integrating ecological management, science education, leisure and tourism, which will improve the regional human settlements and help the development of Chang’an District.