The Little Cahaba was the first river I paddled in a canoe. Like many other U of A students we took off with our Styrofoam cooler full of Busch Lite (a story of drunken river rescue technique for another time).
Anyway, I have paddled both the upper and lower sections many times, but not lately. Alabama Canoe Rides and Float Trips, by John Foshee, is accurate on both runs. The upper section can be fun at higher water levels, it has some nice three-foot drops and a couple good shoals. You need more water to run the upper section than the lower. You can really scratch your boat up if you run either section in lower water. There is no gauge that directly applies to either section. - Tom Land
The put-in is where the road comes close to the water near the Cahaba Valley Church. If you take a right fork off Limestone Parkway, after you get off CR65 and follow signs to Limestone Canoe Rentals, you'll get there. An outfitter runs tubing trips and rents canoes on this section. His place is a good takeout above Bulldog Bend. They'll run shuttle for you if you need it.
This run may be suitable for inner tubes and perhaps rafts if there is enough water.
Tom Land offers this information on the lower section: The lower section has more shoals, but less larger drops. You can really scratch your boat up if you run either section in lower water. The put in is at CR65 at Bulldog Bend. The take out is at the Cahaba CR26 bridge at the end of the Hargrove Shoals section. There is no gauge that directly applies to either section.