It ain't no effing lake, mate. . .
We in the radical green devil-worshiper fringe call it Dominy Sump, after the BuRec monster who criminalized it into existence.
For a reasonable trip, the minimum flow for the Escalante gage is 40 cfs. Check out the recent threads about the SNOTEL site (WIDTSOE #3) and look at the SWE (snow water equivalent) graph.
The snowpack is below average this year. It's a 5-7 day trip and you don't want to run out of water halfway down.