People's Dictionary of the Bible 
Siloah ( Sĭ-Lô'Ah or Sĭl'O-Ah ), R. V., "Shelah," Nehemiah 3:15; or Siloam, John 9:7; John 9:11; or Shiloah . Isaiah 8:1-22; Isaiah 6:1-13. A rivulet on the southeast of Jerusalem, at the foot of Zion and Moriah; supposed by some to be the same with En-rogel and Gihon. There were two pools, the upper, Isaiah 7:3, or king's pool, Nehemiah 2:14, and the lower pool. Isaiah 22:9. There was also a tower at Siloam. Luke 13:4.
Watson's Biblical & Theological Dictionary 
the same as Siloam, Nehemiah 3:15; Luke 13:4; a fountain under the walls of Jerusalem, toward the east, between the city and the brook Kidron, perhaps the same with Enrogel. Near this was a tower, Luke 13:4 .
Kitto's Popular Cyclopedia of Biblial Literature