How I would solve your issue is to dig a hole 2' deeper than the bottom of your pool on the side that the spring runs, fill 18" with gravel and put a pipe up to ground level, the pipe should be large enough to drop an automatic sump pump into.

If you can control the water under the pool, you'll be all set to patch the floor and drop a new liner (I'll give advice on both those things, if you need it)