Moed Katan 5A

קילקולי המים שברשות הרבים וכו׳. חטיטה ⁠— אין, חפירה ⁠— לא.

damaged water cisterns in the public domain and clean them out by removing the dirt and sediment that has accumulated in them. The Talmud infers: Cleaning out the cisterns of dirt and sediment during the intermediate days of a Festival is indeed permitted, but digging a new cistern is not permitted.

אמר רבי יעקב אמר רבי יוחנן: לא שנו אלא שאין רבים צריכין להם, אבל רבים צריכין להם ⁠— אפילו חפירה מותר.

R' Ya’akov said that R' Yoḥanan said: They taught that it is prohibited to dig new cisterns only when the public does not need them; but if the public needs them, even digging new cisterns is permitted.

וכי רבים צריכין להם מי שרי? והתניא: חוטטין בורות שיחין ומערות של יחיד, ואין צריך לומר של רבים, ואין חופרין בורות שיחין ומערות של רבים, ואין צריך לומר של יחיד. מאי לאו, בשרבים צריכין להם?!

The Talmud asks: And when the public needs them, is digging really permitted? But isn’t it taught in a baraita: One may clean out cisterns, ditches, and caves of an individual during the intermediate days of a Festival, and, needless to say, one may clean out those of the public. But one may not dig new cisterns, ditches, or caves of the public during the intermediate days of a Festival, and, needless to say, one may not dig those of an individual. What, is it not so that this baraita is referring to a case where the public needs them, but nevertheless digging new cisterns, ditches, and caves is prohibited?

לא, בשאין רבים צריכין להם.

The Talmud rejects this opinion: No, this baraita is referring to a case where the public does not need them.

דכוותה גבי יחיד, שאין יחיד צריך להם, חטיטה מי שרי? והתניא: בורות שיחין ומערות של יחיד ⁠— כונסין מים לתוכן, אבל לא חוטטין ולא שפין את סדקיהן. ושל רבים ⁠— חוטטין אותן ושפין את סדקיהן.

The Talmud raises a difficulty: It would follow that in the corresponding situation with regard to the cisterns of an individual, the baraita is referring to a case where the individual does not need them. But in that case, is cleaning them out really permitted? Isn’t it taught in a baraita: One may gather water into the cisterns, ditches, and caves of an individual, but one may not clean them out or plaster their cracks; but for those of the public, one may indeed clean out and plaster their cracks? This indicates that on the intermediate days of a Festival, unneeded cisterns belonging to an individual may not even be cleaned out.