We occasionally receive calls about water leaks on wood floors. Many times the floor can be saved if the water is removed quickly, and the floor is dried right away. If the floor buckles or if some of the boards split you will face a more extensive repair. Heat, air circulation, and dehumidification can all help the drying process. Commercial drying services can also be an option. Do not sand a cupped floor flat if it is still wet. Without aggressive measures some floors can take months to dry out. Use a moisture meter to check the final drying.
Once the floor is dry, check to see if the fastening is still tight by looking for board movement. If the floor was very wet often permanent cracks between the boards will persist once the floor is dry. Using fill or small slivers of wood glued into the gaps and refinishing may be an option. Cupping may also be permanent, and can be sanded at this point if it is not too severe.
If you install a new floor it is very important that the subfloor and building components below the floor are well dried out before you start. Installing new wood flooring over a source of moisture can damage the new flooring.