Check for signs of mold along the walls, in crevices and on objects stored in the basement. Mold thrives in damp areas and will remain there even after the water evaporates.
Walk around your basement and sniff the air. Basement air that smells musty often indicates the presence of mildew, which means that your basement has suffered water damage or is overly humid.
Scope out the walls. Basements with water damage may have peeling or discolored paint. Severe, long-term damage often leads to buckled walls.
Walk around with your eyes on the floor. Look for any areas that appear discolored. These areas of discoloration are likely points of entry for water.
Examine the ceiling, particularly around each water pipe. You may see signs of water damage from leaky pipes, such as discolored or warped rafters. The pipes themselves may have condensation.
Feel for dampness around cracks and crevices in the floor and walls. Cracks, which develop as the foundation settles, are a common point of entry for water.
Examine any metal objects you have in your basement, such as a metal toolbox, clothes washer and the fuse box. Rust spots can also indicate water damage.