Plumbing [in] the Depths of the Temple

The Temple had a complex plumbing system which supplied water to many different locations. In this post I would first like to examine the eight places in the Temple where water was located.

Locations where water was used in the Temple

A. Mikveh in the Chamber of Metzoraim (Tosefta Negaim 8:9)
B. Well, or cistern, within the Chamber of the Basin (Middos 5:4)
C. Mikveh above the Chamber of Parvah (Middos 5:3)
D. Channel of flowing water (Middos 3:2)
E. Mikveh above the Water Gate (Yoma 31a)
F. Pit for the Kiyor (Yoma 37a)
G. Place of Drainage Water (Middos 4:7)
H. [Not shown] Mikveh located beneath the Temple which was used by the Kohanim in the Hall of the Fire.

It appears that many of these places were fed by the same source:
• Water from the Eitam Spring (see further below) was used to fill the mikveh above the Water Gate (Yoma 31a) as well as the mikveh above the Chamber of Parvah (Meiri ad loc.).
• The channel of flowing water was also fed by the Eitam Spring (see Tiferes Yisrael to Middos 2:6 §74-5 and Temple Diagram §33).
• The pit for the Kiyor was filled with water from a spring (Rashi to Zevachim 20a).
• The Place of Drainage Water was connected to the channel of water (Chanukas Habayis).

Based on this information the water system may have looked something like this:

Water from the Eitam Spring entered the Temple Mount from the west and was directed beneath the Holy of Holies (see Tiferes Yisrael loc. cit.). From there it entered the Place of Drainage Water (G) and flowed east, through the Kiyor pit (F), into the channel of water (D) which began near the southwest corner of the Altar. This channel ran south, out the Water Gate, and near the gate some of the water was diverted up to the mikveh above the gate (E) as well as to the mikveh above the Chamber of Parvah (C).

I have not seen any sources indicating that this water system also connected to the mikveh in the Chamber of Metzoraim or to the mikveh beneath the Temple used by the Kohanim. We do know that the well, or cistern, in the Chamber of the Basin was not connected to this water system since the water in that chamber was clean and sweet and more suitable for drinking, as opposed to the water found elsewhere in the Temple which was not.

The Eitam Spring and Siphons

The water which fed the system described above came from a spring called Eitam located outside Jerusalem. This spring was at an elevation of approximately 23 amos above the floor of the Courtyard and the water was directed through pipes which ran beneath the floor of the Temple and then up to the mikveh above the Water Gate using the concept of the inverted siphon.

Cross-section showing the flow of water
from the Eitam Spring to the Temple

One difficulty with the system of pipes described above is that, in order to effectively bring water up to the two mikva'os atop the Water Gate and Chamber of Parvah, the entire system must be closed. Unfortunately, at every point along the way there were openings: The Place of Drainage Water needed to be open in order to receive the runoff from the Sanctuary Building roof; the Kiyor pit needed to be open so that the Kiyor could be lowered and raised; the channel of water needed to be open near the Altar to allow the excess blood poured on the Altar to drain into it. This difficulty may be resolved by assuming that the Temple had the means to close the entire system temporarily. On Yom Kippur (which is the only day of the entire year when the two mikva'os were used) the Place of Drainage Water, Kiyor pit, and Altar drains leading into the channel of water would be closed, allowing water to flow up against the pull of gravity and into the mikva'os.

The next post will discuss whether these two mikva'os had the status of a ma'ayan [flowing spring] and whether they possessed the kedushah [sanctity] of the Courtyard or not.