Usually it fills up only about once in 50 years or so, when it can be 4 metres deep (14'). And it is a tad on the large size. Almost 9000 sq.kms. That's 3,400 sq miles. Once full, it takes years to dry up again. The water doesn't run out. This is below sea level and there is nowhere to go.
Just look at those cloudless skies.