Question:
Is the famous hot springs of Chamei Tiveriah considered a valid Mikvah? If a man immerses there for the purpose of purification, or if a woman were to immerse there, is it considered a valid immersion?
Answer:
This depends on an important distinction.
The hot waters of Chamei Tiveriah themselves originate from natural thermal springs. Accordingly, intrinsically, the waters possess the status of spring water (Mayan) and are certainly capable of constituting a valid Mikvah.
The real question, however, is not the source of the water, but rather the specific body of water in which one is immersing. We must determine whether the water remains connected to its original spring source or whether it has been diverted elsewhere and disconnected from the original flow. We must likewise determine how the water arrived at its present location. If it reached the immersion area through pipes, channels, reservoirs, or other systems that raise the classical discussions of Mayim Sheuvim (drawn water), then the halachic status becomes far more complex.
A useful comparison is ordinary city water. Even if the municipal water originally comes from a spring, well, lake, ocean, or other natural source, one cannot simply fill his bathtub and immerse in it, because once the water has been diverted and transported through a piping system it becomes subject to all the classic halachic discussions of drawn water (Mayim Sheuvim). The same question applies to Chamei Tiveriah. The fact that the water originally emerged from a natural spring does not automatically mean that every pool into which it is directed retains the status of the original spring. Rather, one must determine how the water was conveyed, whether it remained connected to its source, and whether the method of transport affects its halachic status.
This concern is particularly relevant because information from the site of Chamei Tiveria itself states that most of the spring water is transferred to the bathing facilities through an underground canal system and that excess water is collected into pools. According to both the Israel Nature and Parks Authority and the official descriptions of Hamei Tveria, most of the thermal spring waters are transferred from the springs to the spa facilities through a system of underground channels and conduits. The National Park specifically states that “most of the waters are transferred to the Hamei Tveria bathhouses through an underground channel system,” while the spa itself states that the waters arrive from underground and are then cooled to bathing temperature before entering the pools. Thus, it appears that the waters are not simply flowing in their original natural state directly into the bathing pools, but are being diverted through man-made systems before reaching the bathing areas. Precisely how these channels are constructed, whether they are considered halachically equivalent to pipes, whether they remain connected to the original source, and whether this affects their status as a Maayan, are all questions that require detailed halachic investigation and cannot be determined from the publicly available information alone.
Accordingly, one cannot automatically assume that every pool or bath within Chamei Tiveriah retains the halachic status of the original spring. The validity depends on details of construction and water flow that require individual verification.
For this reason, a woman should not use Chamei Tiveriah as her Mikvah unless the specific pool has been verified by competent halachic authorities. Likewise, even for a man, it is generally preferable to immerse directly in the Kinneret or another unquestionably valid Mikvah rather than rely on Chamei Tiveriah.
However, if it has been verified that the specific waters remain connected to their natural source and were not rendered problematic through a system comparable to drawn water, then there would be room to validate the immersion.
Conclusion:
The waters of Chamei Tiveriah are intrinsically waters of a natural spring and are potentially valid for immersion. However, because the water is routed through channels and facilities and we do not know the exact halachic status of the specific pools without investigation, one should not assume that immersion there is valid. A woman should not use Chamei Tiveriah as her Mikvah without specific halachic verification, and even for men it is generally preferable to immerse in a clearly valid Mikvah or in the Kinneret.
Sources:
Rama Y.D. 201:75 [everyone agrees is valid for immersion]; Michaber O.C. 160:7 (Valid for Tevilas Yadayim); Rashi Chulin 106a; Beis Yosef 160; Regarding Meiy Ir: Maharsham 3:100; Imrei Yosher 1:80; Taharas Mayim 40 (lenient in NYC); Divrei Yoel Y.D. 75; Minchas Yitzchak 1:146; Shevet Hazlevi 2:103; Taharas Yom Tov 8:18; 11:85; Pischei Mikvaos 5:21 footnote 35; 9:7 footnote 12