By the time Shih-men Reservoir was completed in 1963, there were around 8,845 ponds in Taoyuan Hsien. Ever since the Taoyuan great drainage system and Shih-men Dam were completed, Shih-men Reservoir has supplied sufficient water for irrigation. The ponds were no longer the major supplier of irrigation water and started disappearing or being abandoned. Then the ponds were used for other purposes, mainly construction. For example, the current location of Taoyuan Hsien
government was once a large pond.
The rivers running through Taoyuan plain are short. The water collection areas are small. In the raining season the rivers supply sufficient water for irrigation. Most of time the rivers do not have much water and at times dry up. The ponds were set up to store rainwater.
The ponds were usually built in the lower areas. Builders dig both the red soil and pebble layers, then encircle the area with banks. The red soil is highly adhesive. When mixed with pebbles and pressed tightly, a waterproof bank can be made. Banks encircle the ponds in the low areas. Before the Shih-men Reservoir was constructed, ponds were the major source of irrigation water.
According to statistics, there were as many as ten thousand ponds on the Taoyuan plain before the great draught in 1913. At that time, Taoyuan Hsien was known as the "thousand lakes hsien". All ponds were connected; and thus an irrigation system was created. With the sufficient irrigation system, the rice production of Taoyuan Hsien grew by leaps and bounds. That is how Taoyuan Hsien became the "breadbasket" of northern Taiwan.