Complex sentence: Abbot Christopher built the vaulted hall with two chambers and Sargis who succeeded him got a canal constructed from the Vararakn River for providing water supply to the church, which is still functional.
Split into simpler sentences: Abbot Christopher built the vaulted hall with two chambers. Sargis, who succeeded him, ordered the construction of a canal from the Vararakn River for providing water supply to the church, which is still functional.