In order to provide drinking water for more than 10000 people in Nongchang Village, Chengguan Town, Xincheng County, and divert water for irrigation of arid farmland in the karst rocky mountain area, feeding holes and curtain grouting holes were drilled in the lower reaches of the No.3 opening at the Fuliulang depression over Longguang Underground River, Xincheng County, Guangxi. Crushed stone aggregates were dropped through the feeding hole; then cement mortar or cement slurry was poured into the curtain grouting hole to consolidate the crushed stone aggregates to build the seepage proof curtain to block the underground river course which flows through the Fuliulang depression, which successfully intercepted the discharge of Longguang Underground River to the downstream, and reduced the leakage of water from the depression to the downstream through surface openings and underground caves; meanwhile increasing water overflowing from surface openings to the depression. As a result, A depression reservoir with the capacity of about 2.5 million cubic meters was built, resolving the difficulty in drinking water for more than 10000 people in Nongchang Village, Chengguan Town, alleviating the irrigation of dry farmland, and improving drinking water conditions for local villagers.