These are in feet above Ordnance Datum.
Harrymoor Lower Tank (not on this map) are at 405m aOD = 1319 ft aOD
KB1 about 740 ft aOD
KB2 about 780 ft aOD
KB3 about 980 ft aOD
KB4 about 870 ft aOD
Mellor DSR about 920 aOD