projection issue

[Milkessa Gebeyehu Homa]

Dear QSWATers,

I downloaded the DEM tiles of my study area and merged them successfully. It went well. However, when I projected the merged data to the UTZ zone  of my study area, the minimum elevation value changed to 0 from its original value of 851 and the maximum elevation value changed to 1730 from 1711. Why does this happen and does it affect my watershed delineation if I continue with it?

I have tried several times but the result is not changing. I would be grateful for the solutions you provide me.

yours

Milkessa