Chapter 371: Lowering the Closure Levee to Seal the Gap

Standing beside Ge Hong was a single messenger soldier, who, upon hearing the order, struck the bronze gong once.

Along the bank of the diversion channel, a dozen or so soldiers stood, and upon hearing the signal, they took up shovels and picks and dug through the last few feet of earth sealing the diversion channel.

The diversion channel was roughly six zhang wide and five chi deep, and with the difference in water level, the waters of the Ciliwung River began to flow into the diversion channel.

The river water quickly burst through the earth and surged violently into the diversion channel. The water level in the channel rose steadily, while the channel itself kept collapsing and widening under the force of the current. As the height difference between the waters shrank, the flow in the diversion channel gradually slowed, its erosive force on the banks weakened, the channel gradually stopped collapsing, and in the end it reached a level close to that of the main river—dangerous, but ultimately safe.

The diverted water all poured into the marshland on the northeast side, where the water level rose rapidly before draining entirely into the sea—no silting, no overflow, exactly as anticipated.

Nearly a third of the Ciliwung River's flow had been diverted away, and the current at the gap had dropped from a raging torrent to a steady, calm flow.

After waiting nearly another half hour, someone reported from the diversion channel: "Level water!"

This meant the diversion channel was now operating steadily.

The shout was relayed from man to man until it reached Ge Hong's ears. He said in a low voice: "Lower the closure levee!"

"Clang! Clang!" The messenger soldier struck the bronze gong twice in succession.

At the dam heads on both the north and south banks, four hundred elite soldiers had long been seated waiting. Though they had worked all night, they had eaten their fill of meat and regained their strength.

Hearing the gong, they all rose to their feet, went to the riverbank, and picked up the fist-thick abaca ropes from the ground.

One end of the abaca rope was tied to the closure levee, which sat on the south bank atop log rollers, positioned between the main dam and the spur dike, with the levee's body facing the oncoming upstream current.

Soon, a work chant rang out from the north bank, and all four hundred soldiers pulled together, dragging the closure levee toward the middle of the river.

A moment later, with a splash, the closure levee and the logs beneath it plunged into the river channel, sending up waves taller than a man.

The closure levee was jolted slightly by the current, and the abaca ropes on the north bank snapped taut with a creaking, grinding sound.

"Hold fast!" A Company Commander on the south bank bellowed.

Then the soldiers on the south bank hauled hard on the cables. The cables at both ends of the closure levee drew taut, and a small portion of it sank beneath the water. The current hammered against the levee's body with a rushing roar. At this moment, the closure levee bulged northward and curved southward, lying diagonally across the water's surface, roughly seven or eight zhang from the dam heads at either end.

Ge Hong had already climbed up onto a simple observation platform, staring intently at the gap. Soldiers were out in boats clearing the logs that had jammed up against the dam head.

During this time, the soldiers had to keep constant tension on the ropes against the current, draining their strength rapidly—clearing the logs had to be done with every second counting.

A moment later, a small triangular red flag was raised from one of the boats.

Ge Hong said: "Close the gap!"

"Clang! Clang! Clang!" Three strikes of the bronze gong sounded.

The soldiers hauling cables on both the north and south banks each stepped back three paces in unison, then halted.

Ge Hong said: "North bank, step back three paces." The messenger soldier sounded a gong pattern of one long and two short strikes. A moment later, true enough, the south bank held still while the north bank stepped back three paces, bringing the closure levee parallel to the dam heads.

In this manner, commanding entirely through gong signals, Ge Hong directed more than six hundred men as easily as if they were extensions of his own arm.

Soon the closure levee was within a few chi of the dam heads. By now the gong signals were being struck with great caution, and the soldiers hauling the cables had slowed to stepping back inch by inch. A moment later, the messenger soldiers on both the north and south banks raised their red triangular flags—the signal that the closure levee was flush against the dam heads.

Ge Hong used the bronze gong to direct the soldiers at both ends to gradually release tension. The closure levee slowly sank into the water, and the massive current slammed into its body, kicking up surging spray, while the force was gradually transferred to the dam heads at either end.

As the saying goes, water and fire are merciless. The Ciliwung River looked narrow and gentle, but when truly damming its flow, the force upon it was more than ten thousand jin. Even this placid river suddenly churned with violent waves, fierce and powerful.

The double rows of densely driven piles at both dam heads let out agonizing creaks, and some even shifted and deformed slightly.

A vast quantity of river water, blocked with nowhere to go, surged into the diversion channel. The channel's volume more than doubled in an instant, washing away great swaths of the sandy riverbanks on both sides.

By this time, the soldiers by the diversion channel had all withdrawn, so whether the banks collapsed or not mattered little—this was, after all, nothing but wasteland.

Soon, the closure levee was more than half submerged, with only a little over three chi still showing above the water.

In terms of command, four strikes of the bronze gong rang out across both banks of the Ciliwung River.

"Release the ropes!" The soldiers on both banks obeyed and let go of the cables simultaneously, while designated men coiled the ropes into knots and tossed them into the river.

For if the closure levee were to be smashed apart, these cables would be violently yanked into the river by the immense force—extremely dangerous.

At this moment, everyone held their breath, watching the closure levee. From both banks, one could hear the creaking groans of the closure levee and the dam heads—a sign that the closure levee had not yet settled into place.

Then the water building up behind the closure levee grew ever greater, until finally—with a dull "boom"—the closure levee snapped in two, sending up a huge spray of water in the river. The closure levee rapidly broke apart and was swept downstream by the current. The Ciliwung River surged violently for a while, then returned to calm. The flow into the diversion channel dropped sharply and soon shrank back to its original size.

By now it was noon. Everyone had labored for a long time, and seeing that their efforts had failed, they all felt disheartened.

Ge Hong, by contrast, came down from the observation platform with a smile and said to the messenger soldier: "It's noon—let everyone eat well. There's fish soup today, and it's fresh!" "Yes, sir!" The messenger soldier ran off.

Seeing Wang Ruzhong and Li Yu, Ge Hong smiled and reassured them: "No matter. The closure levee is meant to be expended. As long as the dam heads are intact, that's what counts. Once everyone has eaten their fill, we'll try again this afternoon."

Wang Ruzhong said worriedly: "Should we swap in a fresh batch of soldiers? I can see their strength is much depleted."

Ge Hong shook his head: "Swapping in new men would mean rehearsing everything all over again."

Li Yu brought over bowls and chopsticks: "Enough of that—let's eat first."

Ge Hong didn't take them: "You two eat first." With that, he walked slowly over to the second closure levee and personally tightened every single rope knot.

Wang Ruzhong watched him and knew that the failure of the first closure attempt had left him feeling sour inside, and that he was forcing a smile to comfort the others.

Wang Ruzhong looked at Li Yu, who happened to look back at him at the same moment. Their eyes met in midair, and then Li Yu set down his food and walked over, saying: "I'll help you!"

Ge Hong was taken aback for a moment, then said: "No need."

Wang Ruzhong went around to the other side and began furiously cinching knots tight: "I'm helping too!"

Seeing this, the men under Wang and Li's command could no longer sit still, and one after another they set down their rice bowls and came over to help.

Li Yu laughed and cursed at them: "All of you, get back! Drink every last drop of that fish soup for me!"

After the meal, Ge Hong had everyone rest for a while until their spirits were fully restored, and only then said: "Lower the closure levee."

Immediately, two strikes of the bronze gong sounded from the command post.

This time, the closure levee Ge Hong had selected was shaped narrow at the front and wide at the back, like a wedge—or like a rat's head—and so it was called the "rat-head levee."

The sloped face of this kind of levee converted the force of the current into downward pressure—the swifter the current, the more stable the levee.

This was the signature technique of flood-control masters. Ge Hong had only watched it done a few times and had hastily improvised a copy; whether it would actually work, he had no confidence in his heart.

But having come this far, there was no room for backing down.

Ge Hong issued orders continuously from the command post, and amid the work chants of the soldiers on both banks, the rat-head levee gradually drew up against the dam heads. The familiar creaking of timber sounded once more.

The soldiers clearing the logs dragged their small boats up onto the dry bank, so that if the dam burst, the boats wouldn't be destroyed along with it.

Soon, the rat-head levee settled into place at the gap. The order to release the ropes rang out, the cables were cast into the surging river, the water level in the diversion channel began to rise violently once more, and the timber piles at the dam mouth let out continuous groaning creaks.

The sound was not loud, yet it was extremely grating, setting one's teeth on edge.

On both the north and south banks, eight hundred people held their breath, staring fixedly at the mouth of the dam.

After about the time it takes to drink a cup of tea, the creaking of the timber lessened, the flow at the dam's mouth slowed, and the river gradually calmed from its violent surging—like a wild horse that had finally exhausted its strength.

Ge Hong said in a trembling voice, "It's done!"

Hearing this, the eight hundred soldiers cheered in unison, their cheers causing the mountains and forests and the river to tremble slightly.

Li Yu deliberately ran behind the dam, only to see that water was still flowing in the main channel of the Ciliwung River—the riverbed had merely dropped somewhat, not completely dried up. He hurried back to report, saying with slight panic, "Master Ge, the dam is leaking."

Ge Hong smiled smugly at this and said, "The closing levee isn't solid, so of course it leaks. The technique I'm using is called 'silt-fill self-sealing.'"

When the closing levee is lowered, part of the water passes through it, so it doesn't cut off too much water at once and wash the levee away.

And the Ciliwung River carries much silt—this silt will gradually accumulate and block up against the levee. The longer the time, the more silt builds up, and the stronger the dam becomes.

Water is the softest yet hardest thing in the world. When the Mataram barbarians build dams, they only know how to stuff sandbags in by brute force, piling materials with raw strength—so naturally, however they build, it collapses.

We use the method of overcoming hardness with softness, harnessing water to govern water, using sand to prevent seepage. That's why even straw mats rolled around pebbles can block up the river channel."

Wang and Li listened, dumbfounded, and praised in unison, "Brilliant!"

Li Yu then asked urgently, "Then how long before the water is completely sealed off?"

Ge Hong stroked his beard and said, "One full day and night is enough!"

Wang Ruzhong was overjoyed and said, "Excellent! Then we'll just wait and watch the red barbarians make fools of themselves!"

That afternoon, on the walls of Batavia, Van Diemen was leaning over the crenellations looking down, his belly propped against the battlements, making the motion extremely difficult. "Haha! The water has risen above the riverbanks and overflowed! Look, look!"

Van der Mijl, forgetting his dignity, also leaned over the battlements to look down. He saw that the moat had disappeared entirely—beneath the walls of Batavia stretched a vast lake.

The lake was five to six hundred meters wide. The slum district east of the outer city and the sugarcane fields were all submerged in water. The approach trenches that had kept Van der Mijl from sleeping were all completely flooded—not a single one could be seen.

The Great Xia siege soldiers could only slink back to their siege positions, because the lower reaches of the Ciliwung River were extremely flat, putting the siege positions at nearly the same elevation as the sugarcane fields. The lake water was still spreading toward the positions.

The siege positions were temporarily spared from being swallowed thanks to the blocking of the parallel trenches, but the water level in those trenches was also slowly rising, and the soil on both sides, soaked soft, was collapsing into the water.

At this rate, within 24 hours, the siege camp east of Great Xia's city would also be flooded.

Reus pulled out a telescope and looked into the distance, then said excitedly, "Your Excellency, those Huo Jian barbarians are packing up and retreating in disarray! Hahaha! Go home, barbarians!"

Van der Mijl looked up, and with the naked eye alone he could see Great Xia soldiers dismantling military tents, carrying weapons, and retreating to the southeast—where the upper reaches of the Ciliwung River lay, on slightly higher ground.

No doubt these Huo Jian barbarians wanted to find a spot that wouldn't be flooded to continue their siege.

Hmph. Dream on.

Van der Mijl asked, "How deep is the water below the walls?"

Van Diemen said, "Half a meter, Your Excellency."

"Only half a meter?" Van der Mijl showed slight concern. Even if the terrain were perfectly flat, a height of only half a meter might not be enough to overflow to the southeast and southwest. Van Diemen pulled himself back from the wall, folded his hands over his fat belly, and said with a fawning smile, "Half a meter, yes, yes. I carefully controlled this water depth—not too shallow to fail the flooding effect, and not too deep, so the gentlemen outside the city can still sail boats on the water's surface." Van der Mijl's worry turned to joy, and he asked further, "Then what about the southeast and southwest sides?"

Van Diemen said, "We'll need to wait another day or two, Your Excellency. The south of Batavia is about one and three-quarter meters higher in elevation than the north, so it will take a bit more time for the water to collect—we'll need to wait another day or two, yes, yes."

Van der Mijl said suspiciously, "Water flows to low places. Since the city is higher in the south and lower in the north, how can it flood the enemies outside the southern city?" "Your Excellency, what you say is correct—under natural conditions it couldn't be done. However, through simple sluice gate control, we can achieve this..." As he spoke, Van Diemen bent down, picked up a few pebbles from the city wall, and arranged them on the ground to illustrate.

"... You see, this one represents the southern city wall, this is the moat, this is the Ciliwung River, this is the southern city dam, this is..." Van Diemen used over a dozen pebbles in one breath, each with its own meaning. The whole diagram was extremely abstract—no normal person could possibly understand it. "Stop!" Van der Mijl rubbed his temples and said bluntly, "Let's go to the southern city and see for ourselves."

Van Diemen clapped his hands and stood up, saying awkwardly, "Fine, fine."

The group descended the city wall and rode toward the southern wall. Along the way, Van Diemen seized every opportunity to introduce the city's water conservancy projects, chattering on like a sparrow, endlessly and without pause.

"... Your Excellency, look at that fountain—that's the outlet of the Pankoran reservoir. The reservoir is built in the southern part of the city, using pressure differences to spray water, purifying it through sedimentation and pipe filtration. An exquisite design, yes, yes..."

Van der Mijl, thoroughly annoyed by the disturbance, turned to glance at the fountain. The thing was less a fountain and more an oversized water tap. Quite a few water merchants were queuing with clay jars beneath the fountain to collect water; the filled jars would be transported throughout the city for sale.

This was the key to why the city's canals were so filthy, yet Batavia's residents could still use clean water.

Reus leaned close to his subordinate and whispered jokingly, "Some say Lady Van Diemen is as cold as ice to him—even in bed she doesn't let out a single moan. His chatterbox disease was all driven out of him by his wife."

The subordinate suppressed a laugh and said, "Ha, then when his little fat worm pokes in, wouldn't it shrink right back from the cold?"

"Hahaha..." Reus and his subordinate burst into laughter.

Though Van Diemen hadn't heard what Reus said, he heard the mocking laughter and sensitively lowered his head and fell silent.

The group soon reached the southern city wall. After climbing up, directly below was the moat, and beyond that the slum district. Because of the siege, these paupers had all fled into the city.

South of the slum district were small sugarcane fields, and further south lay the shimmering Ciliwung River, along with woods and wetlands.

The lower reaches of the Ciliwung River flowed from east to west, then curved northward directly south of Batavia, flowing into the city, merging into the moat and canal system, and finally emptying into the sea.

Batavia was built as a copy of Dutch lowland cities, deliberately sited at the river mouth. From the city's founding, a complex system of sluice gates was built to control water levels in segments.

Once on the city wall, Van Diemen pointed at a main water gate on the canal and said, "This gate is used to store water and flush out silt.

When the tide comes in, we close this gate, and the water levels of the Ciliwung River and the moat rise.

When the tide goes out, we open the gate again, using the water level difference to accelerate the flow and push the sand out of the channel.

Not only that—the moat also has its own separate gates, allowing water volume to be regulated in segments. This is to facilitate water storage and flood retention..."

Van der Mijl interrupted impatiently, "Just explain how to flood the enemy positions."

"Yes, yes. We should close the main water gate and shut the moat gates to the minimum. With nowhere for the Ciliwung River to go, the water will back up in the channel. Once the river overflows its banks, it will wash away those gentlemen's tent camps.

As I said before, the Ciliwung River has very little elevation drop, so when it overflows, it spreads in all directions—and the moat will do the same." Hearing this, Reus said, "Damn it! If the moat overflows in all directions, won't it batter the city walls?"

Van Diemen was startled and lowered his head, saying, "That is merely a minor drawback. The gentlemen's trenches outside the city are lower than the ground, so they'll suffer more soaking..." "Heh heh, 'the gentlemen outside the city'? What a coward." Reus said disdainfully.

Van der Mijl understood Van Diemen's meaning and praised, "Absolutely exquisite!"

He quickly calculated in his mind—as long as the southeastern siege camp was also soaked, then neither the Dutch nor Great Xia could do anything to the other. Both sides could return to the negotiating table.

At that point, giving Great Xia forty or fifty thousand florins to send them off would suffice. As long as the Spice Islands remained, as long as Batavia remained, the lost fleet could be rebuilt. The losses of this battle could one day be recouped twofold!

Thinking of this, Van der Mijl gave his secretary a look, and the secretary brought out another Amsterdam Bank draft, with an amount of fifty thousand written on it.

This was the reward for Van Diemen completing the bounty.

Van Diemen accepted the draft. Reus pointed at the distant river surface and said, "What is that?"

Everyone looked where he pointed. Several logs were drifting down the channel, their bark stripped off—clearly shaped by human hands. Under everyone's gaze, the logs were eventually stopped by the water gate, and soldiers fished them out and discarded them.

But soon, palm leaves and abaca rope came floating down the channel as well.

Everyone looked astonished, turning toward Fan Di.

Fan Di, in turn, looked upstream along the Ciliwung River, where the water stretched on and on, vanishing at last into the rainforest.

"It should be the gentlemen outside the city attempting to build a dam."

Royce sneered: "Gentlemen? A pack of savages is all they are! They're building a dam out of grass and leaves — do they think they're beavers? They'd be better off saving their strength and learning to weave skirts with those two materials first."

The Dutch guards around them burst into laughter together.

Van der Meer, however, did not laugh. He looked at Fan Di to confirm: "The Xia people don't have the ability to build a dam across the river, right?"

Fan Di rubbed his hands together, looking somewhat anxious: "Absolutely not. From the moment they landed to now, it's been less than a month — not even enough time to fire bricks. Even if their ships carried bricks, even if they had Dutch engineering masters, a month's time could never be enough to finish a dam. Yes, yes." Van der Meer thought it over — even if those barbarians did have the ability to build a dam, why would they bother?

If they wanted to cut off Batavia's water, they could follow the Mataram's example and toss animal carcasses into the river — wouldn't that cost far less?

Fan Di felt a bit tense and called over a river guard to ask: "Have any other logs floated down the river recently?"

The river guard thought for a moment and said: "There was one more time this morning, but nothing since. The river has been perfectly normal."

Fan Di breathed a sigh of relief. It seemed the Xia people's morning attempt at building the dam had failed — how could logs and straw mats possibly build a dam? He must have been overthinking it. Just as he was about to send the soldiers back, his gaze swept past the Ciliwung River and he suddenly froze, as if turned to stone by Medusa herself, one hand suspended in midair, his posture rather comical.

"Sir, Mr. Fan Di, what's wrong?" The river guard waved a hand in front of his face.

Fan Di stared fixedly at the river, his eyes filled with terror, beads of sweat instantly seeping from his forehead.

"Has the water level of the Ciliwung River... dropped?"

The river guard turned to look: "No, it hasn't."

"No, no! It hasn't dropped — it's stopped. It's not rising anymore. Why isn't it rising? How can it not be rising?" Fan Di said in a panic. The river guard turned back and looked carefully again, realizing that the river's water level indeed hadn't changed for a very long time.

Fan Di sent a soldier to measure the river's depth, and after waiting an hour, had the soldier measure it again.

The river guard returned with a terrified expression: "The water level... the water level... hasn't changed."

Fan Di said in disbelief: "They really can build a dam? A dam built of leaves and rope?"

Van der Meer hurriedly asked: "What's going on? What exactly has happened?"

Fan Di said in terror: "The cup isn't leaking, yet the water isn't increasing — there's only one possibility: the spout is blocked. They really did build the dam! My God!"

Then, as if remembering something, Fan Di abruptly said to the guards: "Go close the tidal sluice gates! Hurry!"

With the Ciliwung River cut off and its flow drastically reduced, seawater would surge in and rapidly salinate the river. Closing the tidal sluice gates could sever the connection between river and sea, protecting the freshwater to the greatest extent possible.

But this was by no means a long-term solution. Once the dam was in place, all the water of the Ciliwung River became stagnant, would soon go foul, and would breed mosquitoes and spread disease.

Whether the city's reservoir or its wells, the water quality of all was affected by the Ciliwung River.

When the Mataram had besieged the city, they dumped corpses and excrement into the river — but at least the river still flowed. Relying on the river's self-purification and the reservoir's purifying ability, it wasn't enough to poison the entire city; they could barely hold on.

But the Xia had directly severed the river at its source — no poison, no plague, a far cleaner method. Yet if they held out stubbornly, the Dutch would soon all die of thirst. Moreover, the falling water level upstream would directly cripple the Pankoran reservoir's fountain-based purification system that relied on elevation differences. One stroke straight at the Dutch's vital point. Batavia's death countdown had begun.

Pink Round

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