The top table on the left shows statistics related to USACE infrastructure age. About 35% of these dam structures are deemed to be in “poor” or “unsatisfactory” condition. USACE navigation structures (median age of 60 years), are slightly older than USACE dams (median age of 55 years). The variation in age is fairly high within both structure types with respective standard deviations of 20 years for dam structures and 28 years for navigation locks and dams. The high standard deviations around these ages are, in part, due to the different eras of USACE infrastructure investment. The maximum age for both navigation and dam structures is around 180 years, which suggests that, in very special cases, both dam and lock chamber structures can long exceed their expected service life. While these 180-year old projects are anomalies in the USACE portfolio, about 19% of USACE multipurpose and FRM dams are between 70 and 90 years old and about 22% of navigation structures are currently between 80 and 100 years old. In other words, more than 20% of USACE structures have already exceeded their respective estimated service lives of 60 and 75 years. See the figures to the right for histograms of the current age distributions of these two types of structures. Note that these age distributions do not take into account any major rehabilitations or structure replacement.
The average USACE infrastructure age is very close to the BEA-estimated "non-buildings" service life.