waist-deep 
adjective & adverb
Of or at a depth to reach the waist: [as adjective]: the waist-deep snow [as adverb]: the anglers were standing waist-deep in frigid water...
- We finally drifted into waist-deep water and dragged the boat onto the beach.
- More than three weeks after the floods began, water still lies waist-deep or higher in some areas.
- They waded waist-deep in the grass in a compact body bearing an improvised stretcher in their midst.