Cat litter should not be flushed down the basement drain, but if it does get in the drain, it will clump and cause a blockage. Cat litter absorbs liquid and does not degrade when more liquid is added. When cat litter gets into the drain in the basement and creates a blockage, you will need to unclog the blockage in order for all other drains in the home to flow quickly through the basement drain to the sewer.
Rent a power auger from a local equipment rental company. You will need a power auger with at least 50 feet of cable.
Remove the trap or screen that covers the drain opening. If the drain is a straight through pipe, you will not need to remove a cap. If your floor drain has a clean out plug, you will use an adjustable wrench to loosen and remove the cap.
Place the auger near the drain. Put on a pair of gloves. Plug the auger into the outlet.
Feed the cable into the drain. When you have a few feet of cable in the drain, set the auger to run in a clockwise direction. Step down on the foot petal as you continue to feed more cable into the drain. If you feel the auger stop feeding or the motor starts to bog, remove your foot from the foot petal.
Turn the switch on the motor to run the auger cable counterclockwise and allow the cable to back out a few feet by stepping down on the foot petal. Stop the foot petal after you have the cable backed out a few feet and switch the motor back to clockwise and continue to feed the cable into the drain farther by stepping on the petal. Keep repeating this step until the auger cable frees the blockage and moves freely in the drainage pipe.
Run two to three 5-gallon buckets of hot water down the drain. If you removed a cap, wrap some Teflon tape around the threads before you screw the cap back on. Replace the screen or drain cover.
This is a dirty job and you should wear old clothes when performing this task. Wash the cable of the power auger off with hot water before winding it back unto the reel.