Standing water in a crawlspace is a serious concern. All attempts need to be made to divert water from draining towards your home. Rain gutters need to be clean and large enough for the size of the home. The ground outside the foundation must be graded away from the home to keep water from pooling next to the foundation. Sprinkler heads need to be properly maintained to prevent them from soaking the foundation and crawlspace vents. Water pipes or drain pipes need to be checked for cracks and leaks. Furnace drain lines need to be drained properly. When all of these concerns are addressed and there is still water pooling in your crawlspace, a drainage system may be required. Sometimes because of a high water table or a spring located within the crawlspace, the problem can not be corrected from outside the structure. There are several different methods for draining the crawlspace depending on how the crawlspace is constructed and the severity of the problem.