Majapahit is one of vast kingdoms and civilizations in Southeast Asia in 14^th century. The kingdom and its capital city are centered in present Trowulan suburban, east Java and bordered by mountain range in the south and river in the east and north. Regarding the geological condition then Majapahit kingdom has a challenge especially to provide the water managements for its agricultural practices. In here, this study aims to assess the hydrology systems developed by Majapahit civilizations and how this system is effective in maintaining vegetation health. Based on the results, the gravity-fed hydrology systems consist of networks involving river, dam, underground and surface water canal and reservoir pond. The water from upstream was managed using dams and channeled into streams and collected inside the ponds. This network spans approximately 10 km from the first dam to the last 6.49 Ha reservoir built in the middle of city. The water channeled from dam to reservoir pond was using natural streams and 2.4 km underground canal. This 40 cm depth man made canal was a water source for agricultural soils since it was used to irrigate the nearby paddy field. During past El Nino in 2019 that has caused prolong drought, the Majapahit irrigation system has provided water for the adjacent paddy field. Based on the vegetation health analysis measured using Normalized Difference Vegetation Index (NDVI), paddy field watered by man made canal shows higher NDVI values or at least has same values compared to the field watered by contemporary canals. Then, the 14^th century irrigation system developed by Majapahit civilization is a valuable heritage that needs to be preserved considering its important functions even in this contemporary era.