The original article goes through the timber mafia connection with the Taliban--illegal logging is worth billions of rupees and the mafia has actively helped the Taliban--and how the latter as well as counter-attacks by the Pakistani army has put the people in the Swat region into a precarious situation. But here's the connection between illegal logging and the flooding:
In the way that horror tends to pile on horror in Pakistan, not only has the flooding been intense in areas where the timber mafia is active but the felled trees, hidden in ravines prior to smuggling them onwards, have caused havoc. Dislodged by torrents of water, they have swept away bridges and people and anything else in their path.
There has been some suggestion that the high volume of timber transported along the rivers has been a factor in the weakening of the dams and retaining walls that are supposed to protect the land from flooding but have proved unequal to the task. Their failure to function has also brought up comparisons to the poor construction that resulted in collapsed government schools during the 2005 earthquake; then, blame landed on corrupt practices and lack of oversight by the authorities in the allocation of construction contracts.
Read the full article (linked at top) for more detail--good stuff throughout--but just take it all as one more example of why fighting corruption and organized crime is intimately tied with creating a more socially and ecological sustainable society.