Bava Metzia 77A

פסידא דפועלים, לא סיירה לארעיה מאורתא ⁠– פסידא דבעל הבית ויהיב להו כפועל בטל.

this is the laborers’ loss, as it is a consequence of their misfortune. But if he did not survey his land the night before, it is the employer’s loss, and he gives them the wages of an idle laborer.

ואמר רבא: האי מאן דאוגיר אגירי לדוולא, ואתא מטרא ⁠– פסידא דפועלים. אתא נהרא ⁠– פסידא דבעל הבית, ויהיב להו כפועל בטל.

And Rava further said: With regard to this one who hires laborers to draw water from a river or a trench to irrigate his field, and rain fell, so that he no longer needs laborers, this is the laborers’ loss. The employer does not need to pay them, as he could not have known ahead of time that this would happen. But if the river comes up and irrigates the field, this is the employer’s loss, as he should have taken this possibility into consideration. And therefore he gives them the wages of an idle laborer.

ואמר רבא: האי מאן דאוגיר אגירי לדוולא, ופסק נהרא בפלגא דיומא, אי לא עביד דפסיק ⁠– פסידא דפועלים. עביד דפסיק ⁠– אי בני מתא, פסידא דפועלים. לאו בני מתא ⁠– פסידא דבעל הבית.

And Rava says: With regard to this one who hires laborers to draw water from a river or a trench to irrigate his field, and the flow of the part of the river used to irrigate the field stopped midday, the halakha depends on the circumstance. If it is not prone to stopping, this is the laborers’ loss, a consequence of their misfortune. If it is prone to stopping, then one acts in accordance with this consideration: If the workers are residents of that city and know that this might happen, it is the laborers’ loss; if the laborers are not residents of that city and are not aware that this is a likely occurrence, it is the employer’s loss.