In this study, the effects of intake-pipe blockage and location of impervio
us boundaries on critical submergence of an intake pipe are presented. Expe
riments were conducted on a horizontal intake pipe sited in a dead-end cana
l flow. Theoretical results and available experimental data are compared. I
t is shown that, as the distance between the intake-pipe entrance and the d
ead end gets smaller than the critical submergence depth, the deviation bet
ween theoretical and experimental results increases. A potential flow solut
ion still gives acceptable results when this distance is smaller than the c
ritical submergence, but it overpredicts by about 80% when the distance bet
ween the intake-pipe entrance becomes much smaller than the critical submer
gence depth.