How to drain the water out of a specific place in minecraft?

I want to mine some sand that's in a specific spot under the water. The problem is, it takes way too long. Is there a way to get the water out of that area somehow? I tried blocking it off by creating a barrier but it's basically just a little lake now.

Fill up the barrier you made with dirt then break the blocks again and it will be clear but don't break the barrier u made otherwise the water will come in and you will have to start again.