The Drought Crisis That Shook Ancient China

In the spring of 239 BCE, the Qin state faced an existential threat. Three consecutive harvest failures—summer, autumn, and winter—had left the Guanzhong Basin’s granaries empty and its people desperate. The Jing River, lifeline of northwestern China’s agriculture, flowed uselessly past parched fields. This was no ordinary drought; it was a catastrophe that could unravel decades of Qin’s military and economic ascendancy.

Young King Ying Zheng, later known as Qin Shi Huang, recognized the stakes. While rival states like Wei and Zhao showed signs of recovery, Qin’s heartland teetered on collapse. The specter of mass famine migrations loomed, potentially leaving the state vulnerable to the “Vertical Alliance”—the perpetual coalition of eastern states waiting to dismember Qin. The solution? A Herculean engineering project: the Zheng Guo Canal, designed to divert the Jing River’s waters across 400 li (≈200 km) of arid plains.

The Midnight Scrolls: A King’s Obsession

After inspecting northern territories ravaged by drought, Ying Zheng became consumed with accelerating the canal’s timeline. Locked in his chambers with canal schematics, the 22-year-old ruler made a revolutionary discovery: the project’s technical challenges—surveying, material sourcing, structural design—had already been overcome by chief engineer Zheng Guo and his team after a decade of trial and error. The remaining obstacle was purely logistical—mobilizing enough labor to complete construction before the critical summer planting season.

This epiphany came with political risks. Pressuring Zheng Guo and administrator Li Si—both brilliant minds who’d already compressed the schedule to an unprecedented five months—could backfire. Ying Zheng devised a subtle strategy: summon all 200+ local foremen (“Work Generals”) to an unprecedented assembly at the Jing River camp, creating grassroots momentum for faster progress while preserving technical integrity.

The Mud-Stained Summit

At dawn, the king arrived to a surreal scene: a cavernous tent filled with county magistrates and peasant foremen, their clothes caked with mud from months of digging. These were no ordinary laborers—many held noble ranks equivalent to 600-dan ministers, yet they stood like “earth statues,” their skin leathered by sun and wind. When Ying Zheng addressed them as “elder brothers” and insisted they sit, the hardened men dropped to the dirt floor without hesitation, sending up clouds of dust that no one dared cough through.

The debate turned explosive. County magistrates from drought-ravaged regions like Xiagui vowed to complete their sections in two months, igniting a chorus of competing pledges. Zheng Guo, the aging hydrologist, slammed his measuring rod: “Water control isn’t war! Rushed work means leaks—and leaks mean famine!” Li Si played mediator, calculating that even with 1 million laborers, each would need to build 2.5 meters of precision-engineered canal daily—an impossible feat.

The Lake of Revelation

Ying Zheng abruptly adjourned the meeting, leading the grime-covered assembly to a restricted reservoir—the “Old Zheng’s Forbidden Pool” used for leakage tests. As the king stripped to his undergarments and plunged in, taboos shattered. Magistrates and foremen followed, their nakedness symbolizing the raw urgency of their mission. Beneath the surface, this was no mere swim: the pool’s carefully maintained water level served as Zheng Guo’s diagnostic tool for detecting hidden fissures in the canal’s bedrock—a metaphor for the project’s invisible challenges.

Emerging refreshed, the assembly feasted on military rations—thick bread, salted beef, vegetable stew—as the sun dipped below the mountains. It was here, on the lakeshore rocks, that Ying Zheng delivered his masterstroke.

The Triple Gambit

First, the king validated Zheng Guo’s technical authority: “I won’t accept a defective canal, even if it’s built quickly.” Then, he revealed contingency preparations:

1. The Craftsman Corps: 1,300 veteran engineers from Sichuan’s Dujiangyan project,咸阳’s workshops, and the Lantian military camp were already mobilized.
2. The Secret Weapon: Li Huan—third son of legendary hydrologist Li Bing—was present, offering his family’s generational expertise.
3. The Reorganization: Li Si became Chancellor, Zheng Guo retained engineering control, and the fiery Xiagui magistrate Bi Yuan was promoted to oversee all civilian labor.

Most crucially, Ying Zheng framed the deadline not as bureaucratic pressure but as national survival: “If we miss summer planting, Qin faces collapse. But if we rush poorly, the canal fails. Both paths lead to ruin—we must find the third way.”

The Echo Through History

That night, the Jing River valley echoed with the Qin battle cry: “Gritty old Qin, face the nation’s calamity together!” The project completed in 236 BCE, transforming 40,000 hectares of saline wasteland into fertile fields—a feat that bought Qin the agricultural surplus needed to launch its unification wars.

The meeting’s legacy transcends irrigation. It showcased Ying Zheng’s leadership alchemy: blending grassroots energy with elite expertise, respecting technical limits while expanding political possibilities. The “bare-assembly” (as historians later called it) became Qin’s template for crisis management—a reminder that when facing existential threats, sometimes the most powerful tool is a king willing to get wet.