Long before we built railroads, interstate highways and airline systems, the country’s circulatory system was its vast network of rivers, which spread across our landmass like life-giving veins and arteries. Even today, people gravitate and have a preference for living near or alongside waterbodies, whether coastal, lakeside or riverfront. Major cities in the United States, as well as in countries around the world, have tended to develop along rivers, giving them access to navigation, the exchange of goods, agricultural irrigation and sources of power.

It began modestly enough. One of the first things settlers did was build grist mills on rivers. You simply did not have a village without a grist mill, writes hydrologist and river scientist Martin Doyle in his new book The Source: How Rivers Made America and How America Remade Its Rivers. Since then we have graduated to about 85,000 dams standing at least 10-feet tall, meaning we have built a U.S. dam about every day since the signing of the Declaration of Independence, giving us flood control, water supply and the ability to generate hydroelectric power.

The Columbia River alone has provided the Northwest with a huge source of hydropower source, says Doyle, who identifies the Columbia River system as one of four major U.S. river systems. The other three are the Eastern Seaboard river system, which includes a series of rivers running west to east from the Connecticut River in the north to the Savannah River in the south; the Colorado River system in the southwest; and of course the granddaddy of them all, the Mississippi River drainage basin, spanning almost the entire continent and allowing for the movement of cotton and tobacco during the country’s early days. Today, the Mississippi still carries barges loaded with a tremendous amount of products, including grain and coal, to the many cities and ports that long ago sprouted along its banks.

Doyle refers to the Mississippi as a “foundational” river, as it serves as a pathway for a major proportion of the population and gave birth to an explosion of agricultural production that fed a nation. It connected people from very different cultures, from the free north to the slave south, and it was the transportation conduit used by Abe Lincoln during his first significant travel from his home in Illinois, floating a small boat down the Mississippi all the way to New Orleans, where he found people living a very different way of life.

To see a graphic depiction of U.S. rivers scaled by flow and appreciate the massiveness of the Mississippi River basin, go to this link: https://pacinst.org/american-rivers-a-graphic/

Over the years, Doyle writes, we have done a marvelous job of clearing rivers, dredging them of wood and silt, and straightening them. Rivers that carry barges are straighter than interstate highways, thanks largely to the Army Corps of Engineers, which has done more to straighten and confine rivers than any agency in the history of the world. It has also played a role in guarding endangered species and protecting wetlands.

Despite feats of engineering that have allowed us to impose our will on rivers and tap them for their ability to spin turbines and produce clean electricity, the movement of water has been mostly shaped by natural processes. Such is the power of the natural accumulation and flow of water.

Though we have dammed rivers to control their most rambunctious activities, climate change, rising water levels and major climatic events have reminded us that water can become an uncontrollable force. That is especially disconcerting when one considers that river infrastructure, such as locks and dams, have been under-resourced for decades, says Doyle, gradually raising the cost of moving goods. While the country’s largest dams (think Hoover Dam and Glen Canyon Dam) have been well cared for, less notable ones have been given less attention. Perhaps more concerning are crumbling levees. (Remember the devastation of the failed New Orleans levee during Hurricane Katrina.) Agricultural levees, in particular, protect enormous swaths of lands, safeguarding farms and, in some cases, towns and cities from flooding.

With the proliferation of transportation systems since the days when rivers flowed supreme, we can easily forget the important role rivers still play, and that rivers served our pioneering nation before we built advanced transport systems to overlay and complement river systems. Then again, Mother Nature has a way of reminding us about the forces truly in charge of our lives, such as water and its naturally-occurring channels that our population still gathers around in inordinate numbers for aesthetic, lifestyle and economic reasons.

Mike Consol (m.consol@irei.com) is editor of Real Assets Adviser. Follow him on Twitter @mikeconsol to read his latest postings.