"The water level could rise to the height of an adult and even submerge underground parking lots," said Wang Jie, project manager from Sino-hydro Corporation Engineering Bureau 15 Co.

The restoration faced enormous challenges due to complex underground structures and a lack of detailed pipeline records. "We didn't know the exact location and depth," Wang explained. "We could only use machinery to dig 30 to 40 centimeters, and then excavate the rest manually. At one point, we discovered high-voltage cables less than 20 centimeters away, which posed serious risks."

According to Zhang Meng, project manager from Xi'an Water Investment, construction was carried out in phased, small-scale enclosures, much like assembling a jigsaw puzzle, to reduce disruption to city traffic and residents.

To maintain water quality, the team implemented a small-scale water circulation system, applied multiple technical solutions to address culvert leakage, carried out harmless silt treatment, and introduced pollutant-filtering aquatic plants. Historical features like stone railings and stools were preserved, while modern amenities, including underground public restrooms, mother-and-baby rooms, and all-gender facilities were added.