As a side note manouvering when you are not moving much through the water is easier to do with a paddle and rudder up. I lift therudder when anchored in high flow as the current will deflect and wedge the rudder creating a resistance and make the kayak sit at an angle

Most my anchoring in stronger currents in WP is running my anchor to the bow into on coming current using the bow to deflect the force of the water flow & like Shane said not tying off & using a cleat & using a small float with about 1m of cord & a SS carebena I can QR & ditch if needs be.
Bought some of those Nylon cleats Shane posted for cheap via EBay kayak supplier, work well. Use one when I Sail my PA also.