Indravarman I was responsible for building the first [L3 208 / irrigation system] of [G 04 / barays] and canals on which the city depended for its water supply, and which farmers in the surrounding areas used to irrigate their rice fields. He built the Lolei baray at the site of his capital in Roluos. This man-made irrigation system was immensely important for expanding the Khmer capital.
Under Indravarman I, the design and size of the temple increased dramatically. [G 26 / Preah] Ko and the Bakong, together with Lolei Temple built by Indravarman's successor, Yasovarman I, marked a [L3 209 / new phase in Khmer architecture]. He began the building of [M 011 / Preah Ko] temple in AD879, south of the Lolei baray, and in AD881 he also began to build the Bakong temple, his own temple-mountain.
These buildings were surrounded by moats which were fed from the Lolei baray. Water flowed through the irrigation system to the Great Lake. Channels divided up the city and provided easy transport. The buildings stood on great mounds of earth, created after excavating the barays and canals.
