How deep was the temple river after the man measured the first thousand cubits?

Answer: Ankle-deep

At each thousand cubits the water grew: ankle-deep, knee-deep, waist-deep, and finally a river that could not be crossed.

“As the man went eastward with a measuring line in his hand, he measured off a thousand cubits and led me through ankle-deep water.”— Ezekiel 47:3 (BSB)