The Water Report - edited by David Moon and David Light (who I normally refer to as "Davids by the Light of the Moon" - not to either one of them, mind you).
Anyway, in every edition they have a section listing water meetings, symposia, conferences, webinars, etc. that they are aware of around the globe - although most of the listings are US events. And this is the case in their latest edition dated April 15, 2013. I was scanning this list because the Groundwater Management Districts Association (GMDA) that I am involved in has its Summer Conference coming up on June 2-4 in Colorado Springs, Colorado, and I wanted to see if they captured this event.
Well they hadn't, but they did list 73 other events scheduled between April 15 and June 7, 2013. Seventy-three water conferences! And only 4 of those were outside the US - one each in Spain, Canada, France and the Netherlands. That's a lot of water dialog for sure - must mean the topic has a fair level of importance.
I don't know how exhaustive their meetings listing is from edition to edition, but based on the quality of the report and of their featured articles I'd guess it's well above average. It is a subscription report, but if you have to know about water, it may be well worth the cost. Give it a look-see.
Oh, while your at it, take a look at the GMDA conference coming up in June, as well. We're not a very big association, but most of the principals are very helpful and a ton of fun. Me? Not so much.