Wat Lao Buddhovāth … Over 35 years of history, culture, and Dhamma practice… is a Pālī compound word and under current standardized Pālī-English, it would be spelled Buddh’ovāda , but Lao and Thai language has a strong tendency to not pronounce the short “a” at the end of a Pālī word. So it would sometimes be seen to be spelled Buddhovad. Another caveat is that the “D” in Pālī is pronounced as a HARD “T” as in Thomas. — Thus we have the current spelling of Buddhovath, because although standardized Pālī-English was available since 1875, the fonts and keyboard did not become readily available until the late 90’s.

Buddha (from Pālī root word Buddha) = of or relating to the Buddha/ enlightened /one who understands The Dhamma (reality as it is)

Ovāth (from Pālī root word ovāda) = exhortation, instruction, or telling how it is

Sīma (from Pālī root word Sīmā) = boundary or parish house for fully ordained monks

It is important to understand the significance of the Water Shrine as a Sīma - a boundary for which Bhikkhus (monks) will assemble every fortnight (full moon and new moon) and recite the Pātimokkha (collection of the 227 precepts - monastic rules established by the Buddha and recorded in the Vinaya Book which also contains the Suttas which explain exactly WHY the Buddha decreed those rules for the monastics to follow). A Sīma is also a location in which Samanera candidates (Novice monks of 10 precepts) are witnessed to go into Upasampada (higher ordination) to become a Bhikkhu.

If you recall about Boun Praveth in June, the story goes that the Prince (a Bhodisatva aka “Buddha-to-be”) and his family was banished by his kingdom because his generosity led to him giving away the kingdom’s money-maker, the white elephant that could bring in rains for crops. His father remained King of the Kingdom. The Prince went to live as a hermit with his family in a remote land filled with dangerous, wild animals and murderous bandits. After about 7 months of The Prince perfecting generosity under extremely difficult situations, The Prince’s father wanted The Prince to return to rule the lands. In order for the King’s men to go into the dangerous hermitage land, a novice monk needed to request a powerful elder monk (Phra Ouphakoud), at the base of the waters of that land, who could tame the evils of the hermitage lands, therefore allowing the King to personally ask for his son, The Prince, to come back and rule the kingdom.

http://www.seasite.niu.edu/lao/lao_folklore/vesantrara_ceremony.htm

So having a water shrine/Sīma is significant because it allows for the role-playing of Boun Praveth to be done as the re-telling of The Vessantara Jātaka, where a novice monk interacts with an elder monk, and being the place where Novice candidates can be witnessed to take on the 227 precepts.