As cities rapidly develop and their underground utility networks become increasingly complex, we, as managers of urban infrastructure, often find ourselves facing this dilemma: Every year, we invest huge sums of money in upgrading drainage networks, but how can we quantitatively assess the actual effectiveness of these projects? Has urban flooding after heavy rainfall been alleviated? Has the operational load on wastewater treatment plants been optimized?

 

In the past, answers to these questions often lacked scientific data support, leaving decision-makers in the awkward situation of "investments visible, yet outcomes difficult to prove." However, the monitoring and predictive diagnostic technology for drainage networks can now provide city managers with a reliable benchmark for measuring investment effectiveness, making the results of underground network management quantifiable, assessable, and verifiable.

Scanning-based precision checkups replace traditional step-by-step examinations.

Traditional renovation is like “opening a blind box”—before construction begins, plans are drawn up based on experience and estimation, and after construction is completed, the results are determined through observation. In contrast, pre-diagnosis technology takes a holistic approach, performing a “CT scan” of the underground pipe network.

(1) Collect the original data before making modifications.

Before the project starts, IoT monitoring devices will be deployed at key nodes in the pipeline network—such as branch connection points, before lift pump stations, and regional discharge outlets—to continuously collect data on flow rate, liquid level, and water quality (e.g., COD, ammonia nitrogen). Typically, pipeline network data from the project area needs to be collected continuously throughout an entire rainy season (3–6 months).

Figure 1: Diagram of Monitoring Equipment

A hydraulic model is constructed by analyzing the flow response curves and water quality variation patterns at each node during rainfall events. For example, if the flow rate in a particular pipeline segment remains persistently high for an extended period after rainfall, it indicates that groundwater infiltration is occurring. Conversely, if water quality indicators exhibit abnormal fluctuations during dry periods, it suggests that there may be combined stormwater and sewage systems or illegal discharge activities.

The result is the generation of a clear “pipeline condition diagnosis map” that precisely identifies problematic pipe sections, mixed connections, and external water infiltration volumes. This enables the design of renovation plans to be targeted and effective, thereby avoiding the massive waste associated with “full-line excavation.”

(2) Real-time monitoring and dynamic adjustment during renovation

During the construction process, the monitoring system operates continuously. As sections of pipeline are repaired or replaced, the monitoring data reflects these changes in real time.

Figure 2: Data Curve Graph

For example, when renovating a pipe section suspected of siltation, monitoring data showed that the water level at that point did not drop as expected after construction began. The technical team immediately launched an analysis and determined that there was a more severe blockage in the unrenovated downstream pipe section. They promptly adjusted the construction plan, prioritizing the clearing of the downstream section to ensure the overall project’s effectiveness.

(3) Post-renovation quantitative assessment and timely corrective actions.

After the project is completed, continue using the same monitoring system to collect data under identical operating conditions (such as rainfall of similar intensity) and conduct a comparative analysis with the data collected before the renovation.

The effectiveness of the renovation can be precisely quantified. For example, by what percentage has groundwater infiltration been reduced? How many times has stormwater overflow pollution decreased during rainy days? Has the influent load on the wastewater treatment plant stabilized? These quantified indicators provide irrefutable scientific evidence for project acceptance.

 

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Visible investment, measurable returns.

In addition to enabling online monitoring of the effectiveness of pipeline network upgrades, the data analytics capabilities underlying this technology are the key to dramatically enhancing governance efficiency.

Through precise positioning and data analysis, it’s possible to avoid “collateral damage” to healthy pipeline networks and thereby save on project investment. For example, by conducting preliminary diagnostics, a large-scale renovation originally planned for 25 kilometers across multiple sections can be narrowed down to focusing on key pipe segments within an 8-kilometer area, saving the budget by more than tens of millions of yuan.

One-time renovation avoids repeated excavations, thoroughly addresses the issue based on data-driven insights, and prevents the “road zipper” phenomenon caused by ineffective measures, thereby saving substantial indirect social costs.

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From then on, the management team “had a clear understanding” and could use data to report achievements to higher authorities, explain their work to the public, and significantly enhance the credibility of their decision-making.

 

After the renovation, the stabilized pipeline network has reduced the intensity and frequency of daily maintenance, enhanced the reliability and resilience of the drainage system, and visibly decreased sewage overflows during rainy days, thereby improving the water quality of urban rivers and lakes. At the same time, this indirectly safeguards the safety of citizens’ lives and property and enhances the living environment.