Yes, you can perform a squat exercise in the pool. When you stand in the shallow-end, most of your upper body would be above the water. That body-weight works against your working muscles.
This is also a good balance exercise. Use pool noodle or any floating device to support you if you find it too difficult to stay balanced.
Stand in the shallow-end with wide stance and put your hands by your side. Keep your back straight.
Make one step forward then go to to a full squat position with a single leg. Hold your arms in front of you parallel to the bottom of the pool. Try to lower your shoulders in the water if you can. Hold that position for two seconds. Raise up, step back and return to the starting position. Repeat until you feel your working muscles, then switch legs and perform the exercise on the other side.
Inhale as you lower your body under the water and exhale as you raise your body up.
Maintain controlled movement and focus on using your quadriceps, hamstrings and glutes.