一楼的也对,但这些更生动和贴切：
make sure that not a single drop leaks out
或
tell a story without missing a single circumstance
或
There must be no leakage of any kind and degree
或
watertight
或
leakproof
或
flawless
或
make a proof all-round and without any omission
这些都可以表达“滴水不漏”,不知帮到楼主没?