When a basement or crawl space has unwanted water the solution is often to install a sump pump. This is a system using a sump pit, with a liner, combined with a sump pump and drain line to automatically remove the water and pump to out of the house. This is a very basic system which when installed properly is very reliable and very effective.
Pick out the best location for the sump pump. This should be where the water tends to gather or the lowest point in the basement or crawl space. If possible, it should be located in a corner or away from any area where people walk or work. This will help protect the pump from damage and protect the people from stepping into the sump pit and being injured.
Dig a pit to match the size sump pit liner you have purchased. Most pits will be a minimum of 24 inches across and 24 to 30 inches deep. Keep the sides smooth and the bottom of the pit level and free of any debris. Insert the pit liner in the pit and make certain it sits level and square. While keeping the liner level, pack dirt around the liner until it is secure and there are no air pockets anywhere around the liner.
Make certain there is no dirt or other debris in the liner, then install the sump pump. Place the pump on the bottom of the liner, making certain it sits level. These pumps are electric and it will need to be plugged into a GFCI (Ground Fault Circuit Interruption() devise for added protection. If at all possible the sump pump should be on a breaker all by itself for even greater protection.
The pump will have an outlet port which you will need to attach a drain line too. The drain line can be made of pvc pipe which will be plumbed up and out of the pit, then out of the basement. The drain line can also be made of something as simple as a garden hose. The flexibility of a hose will make it far easier to route and is far easier to change later if your circumstances or needs change.
The pump is activated by a float switch. When the water in the pit reaches a certain depth, the float activates the switch and the pump motor is turned on. The water is pumped out and the motor will shut off until it is once again activated by the float. This helps preserve the motor and keep the water at a controllable level.