Here's the way to get to the first-hand source of all the flow data on the other sites mentioned here:
http://waterdata.usgs.gov/co/nwis/current/?type=flow
Orgainzed by major river basin. No advertisements, no junk, quick loading even on a dial-up connection, your tax dollars at work providing you the real-time information you want for your boating lifestyle.
When the other sites are down, the USGS site will probably be working. Click on the station ID # and you get the same graph that you're directed to on the other sites. Scan down the second column after the time entry to check the flows in the whole state in a minute. See what the average flow is in the next column and get really depressed.
Or you can check the Colorado DWR site too, which has many sites that are operated by the DWR (lots of irrigation diversions too) though its not as user-friendly:
http://www.dwr.state.co.us/Hydrology/flow_search.asp
--Andy