put your finger in the dyke
put (one's) finger in the dyke
To make a small effort or action to mitigate the damage or spread of something unpleasant, undesirable, or dangerous. He's putting his finger in the dyke, but he really needs to completely overhaul his monthly expenses to keep from going bankrupt. We can't just keep putting our fingers in the dyke every time there's a security breach—we need to figure out how hackers keep getting into the system.
put your finger in the dykeattempt to stem the advance of something undesirable which threatens to overwhelm you. informal
This expression stems from the story of a small Dutch boy who saved his community from flooding by placing his finger in a hole in a dyke.