What to expect
Do not make Ahuashiyacu only a stop at the water. The visit also includes the approach trail in Cordillera Escalera. Leave time to look along the way and ask which visitor route is available on arrival. That keeps the outing worthwhile without making the whole plan depend on entering the water.
How it fits into a journey
Give it its own part of the day with return transport. Keep Lamas for another time rather than continually shortening the visit.