Increasingly frequent flooding in the Chehalis River Basin is causing severe economic impact on local residents. Widespread flooding, including the most recent in January 2009, has significantly damaged Lewis County property, infrastructure and natural resources. Damage estimates for the 2007 flood total approximately $500 million, and the cost of the 2009 flood has not yet been determined. Impact from the flooding extends beyond Lewis County. The recent floods have affected communities in Grays Harbor and Thurston counties, and regular shutdowns of Interstate 5 (I-5) have inflicted region-wide harm.   Lewis County PUD requested a high level review by EES Consulting to confirm whether or not upstream water storage is feasible and cost effective.