Water infrastructure often gets less attention and focus than other types of infrastructure. Both the Federal Highway Administration and the Department of Energy have annual budgets around $46 billion dollars. The Department of Housing and Urban Development has an annual budget of $60 billion. The closest thing the federal government has to a department of water infrastructure, the Bureau of Reclamation, has an annual budget of just $1.1 billion. Water in the US is generally both widely available and inexpensive: my monthly water bill is roughly 5% of the cost of my monthly electricity bill, and the service is far more reliable. And unlike, say, energy, water isn’t the locus of exciting technological change or great power competition.
But this might be changing. Rising demand for water in the arid southwest (which has experienced decades of drought) is creating increasing concern about water availability. Vast amounts of investment is being poured into data center construction, and while data centers are most notable for consuming large amounts of power, they’re also heavy users of water: a large data center can use millions of gallons of water a day for cooling. Google search interest for “water scarcity” has gradually risen over the last two decades.
Because water is such a critical resource, needed for everything from agriculture to manufacturing to artificial intelligence to sustaining basic human life, it's worth understanding how we use water, and how that use has changed over time.
Overview of US water use
Most of us probably remember learning about the water cycle in school. Water falls to the earth via precipitation — rain, snow, sleet — and flows into rivers, lakes, streams, and water-bearing geological strata called aquifers. From there, water continues to move: it goes back into the atmosphere via evapotranspiration, moves from streams and rivers into aquifers (and vice versa), and flows out into the ocean.
Water cycle, via USGS .
Altogether, the US receives about 5 trillion gallons of precipitation a day. Most of that (63%) gets returned to the atmosphere via evapotranspiration. Much of the rest ultimately flows into the Gulf of Mexico (11%), Pacific Ocean (6%), and Atlantic Ocean (2%). About 10% gets stored in surface bodies of water (lakes, reservoirs) or underground aquifers, and 6% flows back into Canada. The remaining 2% is consumed by people in various ways.
Via USGS.
We use water by tapping these various stores and flows. At a high level, water infrastructure resembles electricity infrastructure. In both cases, you have large sources of supply (power plants for electricity and lakes/rivers/underground aquifers for water), which gets transported by a high-capacity transmission system. With electricity transmission is done by high-voltage power lines which connect power plants to substations; with water it's done by large-diameter pipes which connect sources to treatment plants or water storage facilities. From there, as with electricity, water is moved by a distribution system, smaller-capacity pipes and pumps that bring water to individual homes and businesses. And as with electricity, very large consumers of water (along with some smaller consumers) might tap various sources of water directly rather than get their supply via a utility company.
Water infrastructure and use, via USGS .
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