How can I solve this problem I am lost on how to calculate this?

5. In rural Appalachia, many people live in small communities of modest-sized houses built on the narrow flood plains of streams. Surrounding these valley communities are steep, wooded mountainsides. Logging companies operate on these mountainsides. Occasionally the small streams flood, causing significant property damage in the communities. Many people who live in these rural communities believe that the activities of the logging companies on the mountain (building dirt roads and removing trees) have increased the amount of water that runs off the mountains into the streams after a storm, and has thus increased the frequency and severity of damaging floods. This has led some homeowners to sue logging companies for the cost of replacing or repairing houses and other possessions damaged in the floods. Assume that current logging methods do indeed increase the frequency and severity of floods in Appalachia: (3) a. Describe this situation in terms of an externality (2) b. Describe this situation in terms of conflicting property rights claims. (2) c. Describe the tradeoff society faces in deciding how to settle this matter