False.
If there is a complete obstruction, there will be no urine output. However, with partial obstructions, urine output can remain normal or actually increase.
Source
Rose, B. "Urine output in urinary tract obstruction and postobstructive diuresis" Up to Date. Nov 2004.
Grad, Y. et al. "Bitter Pills" N Engl J Med. Nov 2010.