The threat of flooding to Farnsworth House has been present since its construction. However, the frequency and intensity of flood events has increased, especially over the last 20 years.

Each flood event damages the structure and threatens the integrity of the interior and furnishings. Trust Staff take immediate and urgent action to raise the contents of the house above the rising water.

Through the Flood Mitigation Project the National Trust seeks a permanent solution to address the threat of flooding, and preserve this American icon.

From The Silman Report

Mies had a careful understanding of the site’s hydrology, which influenced the design and site placement of the house. The Fox River was known to flood, so Mies located the house a certain distance (approximately one hundred feet) from the river and elevated the main floor approximately five feet above grade. However, just three years after construction was completed, the house experienced its first major flood, with water entering the house and reaching a height of two feet above the interior level. Little information is known from four decades following; only minor flooding was documented in the area.

Flooding in the area has significantly increased over the past twenty years, influenced strongly by an increase in development in the surrounding area. In addition, levels of unprecedented flooding have been noted throughout the United States in the past twenty years, leading to revised flood risk maps and the establishment of a “new normal.” The most serious flood occurred in 1996, when several feet of water flooded the house interior. The following year, another flood entered the house and reached a height of a couple of inches above the main level elevation. In 2008, the house was flooded with approximately eighteen inches of water. This past year, 2013, saw two events worth noting. In March, significant water encroached on the property and flooded portions of the terrace. The following month, another rainstorm raised the water level to within inches of the main level elevation.