The mountains both inside and outside Gansu Province in China overlap, and gullies are formed both vertically and horizontally. The climate is arid and the average annual rainfall is only 500mm. The scarce rainfall, which is distributed unevenly, comes mainly from July to September and leads to great difficulties in supplying drinking water for both people and livestock. Consequently the province is vigorously developing projects to build rainwater catchments because saving rainfall water in the rainy season for drinking water in dry mountain areas is the only solution.
In 2012, with the support of donors from all walks of life, the Hong Kong Christian Council have raised HK$400,000 to build 200 water cellars in Sang Jia Miao Village in Long Men Town, of which 70 water cellars were donated by The Learners Chorus. In the rainy season these water cellars will collect rainwater to provide for the basic needs of 70 families.