The hydrological characteristics of abandoned Old Ganga Canal at Haridwar were investigated during the year 2011. The samples were collected before the diversion (control) at Pathri Super passage (S), and after diversion at Pathri Super passage (S1), Solani Aqueduct (S2), Dhanuari (S3), Piran Kaliyar (S4), Mehawar Kalan (S5) and Roorkee (S6) sampling stations. Among various sampling stations, the quality of Old Ganga Canal water was severely deteriorated at Piran Kaliyar. The hydrological characteristics viz. temperature, turbidity, TS, EC, BOD, COD, Cl-, Ca, Na, K, Mg, total phosphorus, nitrate nitrogen, SO4 2-, Cd, Cu, Cr, Fe, Ni, Mn, Pb, Zn, SPC and FC of water were significantly (P<0.05) different at all the sampling stations in comparison to control. Among various sampling stations, Piran Kaliyar (S4) showed maximum values of physico-chemical and microbiological parameters viz. temperature (19.68 oC), turbidity (11.88 NTU), TS (278 mg L -1), EC (4.55 mg L -1), BOD (270.42 mg L -1), COD (289.74 mg L -1), Cl- (184.67 mg L -1), Ca (199.64 mg L -1), Na (63.85 mg L -1), K (54.87 mg L -1), Mg (165.84 mg L -1), total phosphorus (42.87 mg L -1), nitrate nitrogen (48.85 mg L -1), SO4 2- (234.55 mg L -1), Cd (1.12 mg L -1), Cu (1.74 mg L -1), Cr (0.58 mg L -1), Fe (5.69 mg L -1), Ni (1.58 mg L -1), Mn (0.36 mg L -1), Pb (0.64 mg L -1), Zn (1.87 mg L -1), SPC (8.5×109 SPC ml -1) and FC (9.6×108 FC 100 ml -1) in canal water. The water quality index (WQI) rating of canal water was of bad at sampling stations S, S1, S2 and very bad at S3, S4 S5 and S6 sampling stations. Thus, the canal water was not found suitable for ecological health of Old Ganga Canal.