Last month this column addressed water resources infrastructure and pointed out that every four years, the American Society of Civil Engineers (ASCE) evaluates and grades major infrastructure categories. The 2013 assessment was most disturbing. Of the seven water-related categories, grades ranged from C+ to D- with five of the seven categories scoring D or D-, an altogether dismal showing. Most of the information in this article is drawn from the 2013 assessment.

This month, the column addresses levees, a category that scored D-.

So what are levees? They are man-made structures along stream banks whose purpose is to control flood flows or, in some cases, divert these flows.

ASCE estimates that the nation has 100,000 miles of levees. Most of the levees were originally constructed to protect farmland. Increasingly however, levees are used to "protect" communities. I think we are all aware of how well levees protected the Lower Ninth Ward of New Orleans from the Hurricane Katrina flood surge.

Still, many levees do their jobs and do them well. ASCE estimated that in 2011, U. S. levees and dams prevented $141 billion in potential flood damages. If this amount of money was saved in one year alone, why is there concern about levees? Why did ASCE grade levees with a D-? Here is the answer.

The U. S. Army Corps of Engineers (USACE) has constructed about 15 percent of the nation's levees. The average age of these levees is more than 55 years old. While all receive maintenance, there may not be sufficient funding to maintain them adequately. The most recent evaluation of these levees indicate that only 8 percent are in acceptable condition, 69 percent are minimally acceptable, and the other 22 percent unacceptable. OOPS!

Why is this the case? It's simple! The USACE's budget is supplied by Congress and appropriations for levee maintenance fall far short of what is needed to bring USACE levees to an acceptable condition.

What about the other 85,000 miles of levees? Most of these levees are locally owned and it has been very difficult for ASCE to obtain adequate information about them. However, I would speculate that the percentage of acceptable levees probably is similar to that of the USACE levees.

So what can be done to insure that our 100,000 miles of levees are repaired or rehabilitated? The answer is: spend money. The National Committee on Levee Safety estimates that it would take expenditures of roughly $100 billion to bring all levees in the U. S. to acceptable standards. If this were to happen, where would the money come from? Certainly, some would come from the federal government. But since 85 percent of levees are not federally owned, the money for their repair most likely would need to be raised from state and local sources.

Will this happen? Will the money be raised to repair and rehabilitate our nation's levees, an ounce of prevention? We are living in a time of climate change. Severe weather is becoming more commonplace. What happens, not if, but when we have another Category 4 or Category 5 hurricane or a 1000 year flood? Will our levees in their present condition do the job? I'm not optimistic. Stay tuned!