Water is diamagnetic .when the current pasess through the wires between current poles magnetic induction will be created and magnetic field will be created .then when rain is falling due to the magnetic field water should not touch the wire as it is diamagnetic . but this wont happens why ?

@mardana 
water is not fully diamagnetic , its slight diamagnetic , like 80 percent paramagnetic , and and 20 percent diamagnetic , 
and due to that its advised to switch off the power service at the time of raining , 
and 1 more thing – there will be atrong coating in the electric transmission wire , 
so, water will not in contact with the inner side of wire , 

HOPE IT CLEARS NOW 
ALL THE BEST ..