1) The Water Security Agency of Sask reports flows in cubic metres per second (cms):
https://www.wsask.ca/Lakes-and-Rivers/S ... atershed-/You can find current and historical flow info at this link
http://www.wateroffice.ec.gc.ca/Here's the 2012 data at PA, if the link works:
http://www.wsc.ec.gc.ca/applications/H2 ... &year=2012What you should note is how variable the discharge is. It depends very much on whether it's a dry year or a wet year, and if there's been a recent rain or not.
I would expect flows at about 5 km/hour, give or take 2 km/hr. But, don't count on this to push you along. A wind will always funnel to follow the valley and it will usually seem to be a headwind. A moderate headwind will easily overcome the advantage from the current.
The higher flow rates will push you along a little more strongly, but it also means that you don't have to meander nearly so much and are running aground on sandbars less often. That aspect can be a larger factor than the actual river speed.
2) There will be bugs. They may or may not be bad. That's the time of year for west nile so consider precautions in the presence of even low numbers of mosquitoes.
3) My experience with the N.Sask.R. is limited to the section from Borden Bridge to Fort Carleton. The banks were quite muddy, as was the water. However, you will still be able to filter to obtain water, but you'll be clearing your filter much more often and a prefilter will likely be of some benefit. So might a container that will allow settling of the water overnight. I wouldn't count on the streams that join the river having much flow, and what flow there is is not likely to be any better than the river, and may be worse due to agricultural runoff.
But, there are no portages so maybe a 5 gallon water jug might be a worthy addition if space allows; it could be refilled where you do find good access to water in various communities en route. The filter will carry you through if/when the jug runs out. A couple of 10L MSR dromedaries (or similar) would take almost no room in the canoe or kayak, and conform to the bottom of the boat keeping the centre of gravity low. A wine bladder from a consumed box of wine will work similarly, but not be as tough.
It's a beautiful river valley, by the way. Oh, and that valley will block most of your cell reception unless it has improved in recent years (unlikely along much of the route). In the past I have had to hike up 1 km out of the valley to get reception (same is true for the South Sask River which I paddle more often).
I recommend not to paddle over Athabasca Falls, that could be bad, though a friend did survive it:
http://www.paddlinglight.com/articles/d ... -crossing/For more specific advice, I would contact Clearwater Canoeing (owner Vinessa Currie lives very near to the river and often guides trips on it).
http://www.clearwatercanoeing.ca/Also CanoeSki Discovery Company (Cliff is in Saskatoon but often guides trips on the N Sask R):
http://www.canoeski.com/Tell 'em Bryan sent ya.
Cheers,
Bryan