"If nothing else, it will be completed by the end of this year." Zheng Guo looked at the river in front of him that countless Hu people kept opening up with shovels and flat shoulders, and his face was pleased.

After arriving in the Hetao, Zheng Guo spent several months traveling throughout the Hetao area, and finally chose to dig a canal in Helan County to build water conservancy.

The river flows from the east of Helan County, and if a canal can be opened to extend to the foot of Helan Mountain, and finally flow into the river to the north, then Helan County will have an additional 100,000 hectares of fertile land.

In addition to irrigation, the canal also served as a navigable transporter of coal from Helan Mountain to all parts of the Zhao Kingdom.

"Thanks to Mr. 's help, it would not have been possible to complete such a magnificent project in such a short time without the help of one person." Chestnut bowed and said admiringly.

I have to say that professionals are professionals, he didn't plan the canal route for more than a year, and after Zheng Guo came, it was done in a few months.

Other problems such as poor water level, sediment dredging, bridge building, sluice gates, and Tianjin ferries that have plagued chestnut belly for a long time have also been solved by Zheng Guo.

During this period, the Yellow River was not short of water, and the vegetation of the Loess Plateau was not destroyed, but after all, the Yellow River flowed through the Loess Plateau, and the sediment content was still very high.

However, there are very few parts of the Loess Plateau that flow through the upper reaches of the Yellow River, so the sediment content of the river in Helan County is not high.

But the canal is not like the Yellow River, the water flow is more gentle, the sediment is more likely to sink, once the accumulation is formed, the riverbed will rise, the river channel will be blocked, and the canal will lose its effect.

In order to solve this problem, Zheng Guo built a wooden cage with wood in the upper reaches of the river, filled it with boulders, and formed a stone wall, and a large number of stone walls were arranged into a weir bone, which was three or four miles long.

Slow down the river to this point, precipitate the coarse sand in the river water, and divert the fine sand into the channel. In this way, it can not only solve the problem of excessive sediment content in the canal, but also can be used to irrigate farmland, reduce the alkali content of cultivated land, improve the soil, and play the role of fertilizing the field.

The river mud is very fertile, and the people downstream dig up the river mud every winter to fertilize the fields.

"Starting next year, I, Helan County, will have the same fertile land as the Central Plains." Lema said excitedly.

If it is said that Li Bao still understands some water conservancy, even without Zheng Guo's help, he can build the canal sooner or later by relying on time, then Lejian really doesn't understand it at all.

Zheng Guo's arrival is no less than a long drought and a rainy day, and he knows his hometown well, after all, Helan County is well governed, and it is also his political achievement.

His father's aura is too big, and when he was in Yan Kingdom, others kept saying how his father Le Yi was, and even his title of Chang Guojun was inherited from his father.

When he came to Zhao Guo, Lejian didn't want to be shrouded in his father's aura all the time.

"I think too much, this is just the main canal, even if it is dug through, the boats will be gone. If you want to irrigate the farmland, you still have to dig auxiliary irrigation canals, including small ditches that lead to the fields, but it is still far away. It will take at least two or three years to complete it all. Zheng Guo said angrily.

Compared with the previous ones, the latter ones are the most troublesome, and each auxiliary canal must be designed to ensure that the water can flow to the fields step by step.

If Zhao Guo just wanted to be like Fucha, it would be much simpler to dig a ditch to transport troops and grain, and one or two hundred thousand prisoners would not be able to dig it through in a long time.

"If it takes so long for a Helan County to take such a long time, won't it take one or two decades for the entire Hetao?" Chestnut frowned, he also planned to put Hetao on the right track within five years, and build it into the second largest grain production base in Zhao within ten years.

Now it will take a decade or two to build a water conservancy project alone, and won't the rest be completed until he dies of old age?

"It won't take long for me to have the canal plans for other counties ready. When the canal is dug up, half of the manpower will be freed up to go to other counties. For the rest of the auxiliary canals, third-level canals, and fourth-level canals, the Hu people dug part of it, and the local civilians dug part of it. It is estimated that in five to seven years, the entire Hetao can be built with similar water facilities. Zheng Guo shook his head and said proudly.

For more than two years, the people of Hetao were only responsible for cultivating farmland, building houses, building schools, other coal mining, digging canals, and building official roads, all of which were done by Hu captives.

By the time the farmland reclamation is over next year, it will be able to free up manpower. Of course, the end of reclamation does not mean that there is no wasteland to be cultivated, but that the cultivated land has reached the upper limit of what can be cultivated, and even if it continues to be cultivated, there is no extra energy to cultivate.

"It's still a bit long, can't it be any faster?" Chestnut looked at Zheng Guo. There is no governor in Zhao's official position, his position is only Zhao Kuo for the better development of the Hetao, specially established, a total of only ten years, after the expiration of the term, he will return to the imperial court.

He hopes to be able to build the loop into what he wants it to be during his tenure.

"It's already very fast, and this is still because there are 120,000 captives who work non-stop every day, otherwise ten years will not be enough, at least one generation. Although the Hetao has fertile soil and abundant water and grass, the rainfall is far less than that of the Central Plains. Zheng Guo said.

Although he did not know what the 400 millimeters of precipitation line was, he knew the importance of rainfall for agriculture.

From the north to the west of the Hetao, the rainfall is decreasing. From the east to the south, the rainfall increases rapidly, and the Hetao is the transition zone, coupled with the special topography formed by the Yinshan, Helan Mountains and the Yellow River, resulting in a suitable environment for farming and pasture.

Even if the precipitation in this era was much higher than that of later generations, and the Hetao had just reached the critical level of the 400 mm precipitation line, water conservancy would be absolutely indispensable if it was to truly change from pastures to farming.

"In addition, I plan to dig three large lakes here, here, and here to store water, to adjust the water level, and to prevent floods and droughts." Zheng Guo pointed to a place on the map, on the south and north sides of Helan Mountain, and Shuofang County.

These three points were carefully selected by him and are ideal for use as water storage lakes, where rice can be grown and fish can be raised to improve the lives of the local people.

As for the east bank of the Yellow River, which is the northerner part of the Quyan homeland, it can continue to be used for grazing. However, according to Zheng Guo's observations, the carrying capacity of this land is limited, and if overgrazing is possible, it is likely to lead to desertification of the soil.