if an action or a decision opens the floodgates, it allows something to happen a lot or allows many people to do something that was not previously allowed.

If they win their case it could open the floodgates to others with similar compensation claims. (often + to)

• have someone's number
• have someone taped
• have something burning a hole in pocket
• have something burning a hole in your pocket
• have something coming out ears
• have something coming out of ears
• have something coming out of your ears
• have something coming out your ears
• have something down pat
• have something down to a fine art
• have something down to a science
• have something going for
• have something going for it
• have something going for you
• have something going with
• have something going with someone
• have something hanging over head
• have something hanging over your head
• have something in common
• have something in common with
• have something in common with someone
• have something in common with something
• have something in hand
• have something in mind
• have something in sights