Alternatively, feel free to send such information for publication on Playak. After all, river information is one the the very basic functions of Playak... We've been publishing such info since 1996...
To contribute:
playak.com/overview.php#contribute
PS skinnyboater: I'm not sure how much the world needs another such online river database. We have Playak for global river info, American Whitewater with a focus on the US, lots of very good regional sites, and then many such sites in other languages, such as eauxvives.org in France, several German sites etc etc. I think your chances of creating a succesful site will be better if you start something with a very unique angle...