ὑδροφύλαξ

ακος, ὁ
A. guard or inspector of aqueducts or irrigation-works, PLond. 1.131r.205 (i A. D.), BGU 621.6 (ii A. D.), Cod.Just. 11.43.10.4, etc.
Liddell, Scott & Jones
A Greek-English Lexicon, 1940
An open-access project