Track watering

I was looking at this article in the English Russia blog about a tram (light rail) depot in Russia, the second to last photo has me wondering though. The caption for the photo before it says they're going out to "water" the city trunk lines, then the next photo shows a trolley with nozzles on the back pouring water onto the tracks. Does anybody know the reason for this practice? Is it to clear the flangeways? Is it to clean the rails for a better electrical contact?

Here's the article: http://englishrussia.com/index.php/2010 ... more-19383 The photo in question is towards the bottom.

*the second half seems to have disappeared.
Anyway, I assume it is for lubrication on sharp curves on street trackage. Oil lubrication would adversely affect the performance of automobile tires that naturally would come in contact with such trackage. This is a practice also seen in Toronto's system, also on the Keihan Keishin Line (street running portion) in Japan.