Construction crews on October 9 were working at a sewage treatment project site along Mulian Road in Tianxin District, Changsha, where machinery hummed quietly inside construction fencing as workers employed an "inverted well" technique for underground operations. The project, launched in December 2025 with a total investment of approximately 621 million yuan, is a key undertaking in the "15th Five-Year Plan" era of Changsha's drainage pipe network construction.

Changsha's newly issued Action Plan for Comprehensively Advancing Urban Renewal (2026-2030) calls for renovating aging water supply pipe networks and secondary water supply facilities, coordinating the separation of rainwater and sewage, and advancing sewage system upgrades in pollution catchment areas including Xinkaipu, Kaifu, and Muyun. Water enters treatment plants from the Xiang River and returns from households back to the plants — and in that circular journey lies the peace of mind of water security for every household.

Where to start

Changsha Water Group currently operates nine water treatment plants with a combined daily supply capacity of 2.9 million tons, while the Zhushuqiao water diversion project delivers 700,000 tons daily, serving a supply area of 956 square kilometers. This network, divided by the Xiang River into two relatively independent subsystems — one east of the river and one west — runs north to south, collectively forming the city's water supply safety net.

Under the "15th Five-Year Plan" water supply blueprint, Changsha will continue expanding westward and toward new urban districts, steadily improving a multi-source, multi-plant, interconnected water supply framework.

This network is still stretching westward. The much-watched Leifeng Water Treatment Plant and its water intake system project, invested and built by Changsha Water Group, will serve areas including Meixi Lake International New City and Changsha High-Tech Zone. Once operational, it will cover approximately 90 square kilometers of water supply and directly serve nearly one million permanent residents nearby.

The project is planned for a total daily water supply capacity of 600,000 cubic meters, with the first phase building 300,000 cubic meters. Overall progress has already exceeded 35%, with the No. 2 clean water tank successfully commissioned and multiple water treatment facilities topping out. The main works are scheduled for basic completion by November 2026 and water supply by 2027, laying a critical piece in Changsha's "15th Five-Year Plan" water supply layout.

As the framework extends, scheduling must keep pace. Since the start of this year, Changsha Water Group has coordinated and optimized the supply areas of five plants including Nanhu and Houzishi, cleared bottleneck sections along key pipelines such as Kaifu Avenue, and completed the construction and expansion of booster stations including Jinxing North Road and Xinglian, further enhancing cross-regional allocation capacity.

During summer and winter peak demand and extreme weather, it is the plants, booster stations, and interconnected pipe networks working behind the scenes that ensure residents turn on their taps and get water that flows steadily and abundantly.

Clearing bottlenecks, opening up the water supply artery

The water supply network is the crucial leg of the journey from plant to faucet. Water leaving the treatment plant travels through an intricate web of municipal trunk mains, distribution pipes, and booster facilities, flowing ceaselessly into millions of homes.

The denser the network, the stronger the safeguard — and the heavier the responsibility. Any unclogged bottleneck or underpowered booster station could leave residents at the end of the line short of adequate water.

To ensure water flows where it is needed, Changsha is methodically clearing blockages in the network: coordinating the supply areas of multiple plants, connecting key pipeline sections such as Kaifu Avenue, and building and expanding a series of booster stations to make allocation between east and west, old and new urban areas more flexible.

Regional booster stations act like control valves on the water supply network, flexibly dispatching water based on peak demand and pressure changes to push it farther, higher, and to where it is needed most. Wherever the city expands, water mains and booster facilities extend alongside, and the "15th Five-Year Plan" water supply framework is steadily taking shape.

What matters most to residents is the renovation of aging water supply pipes and secondary water supply facilities. The Action Plan for Comprehensively Advancing Urban Renewal in Changsha (2026-2030) explicitly calls for upgrading aging water supply networks and secondary water supply facilities. The Hunan provincial housing and construction department has also included secondary water supply facility renovation in the key support category of "water supply network leakage control and aging renovation" within urban underground pipe networks.

Renovation work includes simultaneously updating old vertical pipes inside buildings, pump room units, and metering facilities. As the projects advance in batches, problems such as aging pipes, unstable water pressure, and difficulty getting water to upper floors will gradually ease, giving residents greater assurance from the source to the faucet.

Integrated plant-network management for 4,650 kilometers of drainage pipes

The story of water goes beyond supply — it also involves drainage. In October 2024, the Changsha Housing and Construction Bureau signed entrusted operation agreements with subsidiaries of Changsha Water Group, adopting a "entrusted operation plus performance-based contract management" model to transfer 4,650 kilometers of municipal drainage pipes and 31 pumping stations in batches, establishing an "integrated plant-station-network" framework — this is Changsha's exploration of "integrated plant-network management with performance-based payment."

In the past, plants were plants and networks were networks, each managed separately. Now there is unified special planning, unified technical standards, unified construction management, unified operation and maintenance, and unified funding guarantees, striving to ensure sewage can enter, be treated, and be discharged properly.

With institutional mechanisms streamlined, pipe network construction is accelerating in tandem. Entering the "15th Five-Year Plan" period, Changsha plans to implement 105 drainage pipe network renovation projects, building and renovating approximately 1,445 kilometers of pipes, and accelerating the correction of identified mixed and misconnected pipes as well as repair of defects and structural damage.

To minimize disruption to urban operations, most new pipe networks use trenchless pipe-jacking technology, with some projects exceeding 70% trenchless methods — while traffic flows above ground during the day, the underground network quietly upgrades beneath.

The Xinkaipu project is a model of this mechanism in action. Located in Tianxin District, it is a key project in Changsha's urban sewage treatment reform. "The project focuses on four main tasks: building approximately 30 kilometers of new sewage pipes along municipal roads including Mulian Road and Tianxin Avenue, along with 23 smart interception wells; implementing source renovation of approximately 595 hectares of low-concentration plots; repairing grade three and four structural defects in existing pipe networks; and renovating the Baijia River interception dam," said Xu Ranzhi, deputy director of the Project Management Department at Changsha Drainage Facilities Management Co., Ltd., in an interview.

The essence of plant-network integration is upgrading from single sewage treatment to full-domain sewage system governance. The project is expected to be basically completed by the end of 2026, at which point the annual weighted average BOD5 concentration of influent at the Xinkaipu Sewage Treatment Plant will reach 100 milligrams per liter or above.

Less waterlogging on rainy days, gradually improving water quality in rivers

Pipe networks are buried underground, and what residents notice most directly is less water pooling on rainy days. Xu Ranzhi told reporters that most of the original pipe network in the project area was combined sewer, meaning rainwater and sewage mixed together during the rainy season, and poor drainage easily caused waterlogging. After renovation, sewage and rainwater each flow through separate pipes, and the new smart interception wells can precisely regulate water volume based on water levels and flow rates, significantly reducing road surface waterlogging and making rainy-day travel safer.

The results of "integrated plant-network management with performance-based payment" are becoming visible. According to the Changsha housing and construction department, in 2025 the average annual influent BOD5 concentration at urban sewage treatment plants in Changsha reached 86.5 milligrams per liter, up 7.2% from the previous year. Fifteen sewage treatment plants have implemented performance-based payment, which is expected to save approximately 110 million yuan annually in sewage treatment service fees.

Currently, renovations in pollution catchment areas including Xinkaipu and Kaifu are rolling out, with the Muyun area also under planning. The city's 15 sewage treatment plants are connected with 4,621 kilometers of drainage pipes, with a total daily sewage treatment design capacity of 1.55 million tons. Collection, conveyance, treatment, and discharge are all linked, and the water environment around residents is improving step by step, with water quality in the city's rivers quietly getting better.

Looking further ahead to 2035, according to the plan, the daily water supply in Changsha's main urban area will reach approximately 3.5 million tons. A single drop of water is charting a steadier, clearer path through this "city of mountains, water, and islands."