saw a college age couple, complete with shorts, bikini (for her) & a walmart raft heading up there today... although they obviously have not taken Bio 101 & covered Darwin's Survival of the Fittest yet!
luckily for them, West Metro Fire District was conducting swiftwater rescue training between elbow & screaming quarter mile, ie of little help to this adventurous couple.
the water is definitely cold now, so keep that in mind. on the daily cycle of water flows, afternoon is gonna be the lowest level of the day, but you probably won't see less than 700 from here on out. also, this section seems to be highly overgrown with vegetation along the banks & is sticking further into the river as it rises, so keep that in mind for eddying out, or limited control drivers of the kayak & where the current takes them.
i would start out in the park down below & see how you're friend does. much safer, easier to get out & less obstacles to deal with... plus closer to people (help if need be)
have fun, be safe!