Removing the water from a pool cover can make your pool cover last longer by reducing the stress on the cover through the off-season and the water must be removed before opening the pool in the spring. 
While the water on the cover can be removed from siphoning on above ground pools and on some in ground pools when the terrain around the pool slopes to a discharge point lower then the water level in the cover it is far easier and more reliable to use a pump. There are pumps available special for pool covers that will allow the water to be pumped down to a very low level. If you remove the water from your pool cover after every heavy rainstorm or heavy snow melt the chances of you having a pool cover fail or fall into the pool are drastically reduced in addition to the time spent in the spring opening pumping off the water.
Some of the pool pumps available include the Little Giant PCPK-1, PE-1-PCP, and NK-2. Rule Pumps has the model 1800 pump, which is also a good choice. The pumps can be found for around $100. The pumps come with a long cord and should be placed as close to the center of the cover as possible in the lowest point where water will gather when you put the cover on in the fall when you cover the pool. If your pool is in a spot where leaves gather on the top of the pool the leaves may foul the pump intake.
If you take a plastic bucket and drill holes in the bucket making a strainer out of the bucket then place the pump in the bucket the chances of the pump intake fouling with leaves is greatly reduced. Make sure that wherever you place the pump the plug on the cord is out of the pool and won’t end up under water. If you have a switched outlet near the pool that you can plug an outdoor rated extension cord into and run the extension cord to the pump it’s a big plus. Even better is being able to see the water on the cover and the discharge of the hose from inside. Simply looking out seeing the water and throwing the switch then seeing the water pumping out with a remote switch makes keeping the water on top of the cover easy through the whole off season. Keeping the water off your cover is a task well worth the effort.
