Americans are conserving water in their homes like never before, according to a U.S. Geological Survey (USGS) report released this month.

In per capita terms, domestic water use has plummeted from 112 gallons per day in 1980 to just 82 gallons in 2015, a 27 percent decrease. Take 30 gallon-sized milk jugs, fill them up with water and set them aside — that’s how much water you’re saving, every day, relative to the average American in 1980. For a typical family of four that means about a half-ton of water saved, or eight cubic feet, every single day relative to 1980.

For the purposes of the USGS data, domestic water use encompasses everything we do with water at home. “Common indoor water uses are drinking, food preparation, washing clothes and dishes, bathing, and flushing toilets,” the report explains. “Common outdoor uses are watering lawns and gardens or maintaining pools, ponds, or other landscape features in a domestic environment.”

The report credits a number of federal policy interventions with reducing home water use. The National Energy Policy Act of 1992 is a big one. It established efficiency standards for toilets (the now ubiquitous 1.6 gallons per flush), bathroom faucets (2.2 gallons per minute at 60 psi) and shower heads (2.5 gallons per minute at 80 psi). The legislation passed with overwhelming bipartisan support and was signed into law by President George H.W. Bush. Further amendments to the bill, passed in 2005, improved efficiencies for water-using appliances, such as dishwashers and washing machines.

The EPA estimates that 70 percent of our total home water consumption happens indoors, with the remainder going to outdoor uses. But these numbers vary considerably by region, with households in arid Western states devoting 50 percent or more of their annual water budget to maintaining lawns and landscaping. As a result, per capita domestic water use varies greatly at the state level, ranging from 35 gallons per day in Connecticut to 184 gallons in Idaho.

It’s worth pointing out that domestic water use accounts for just a tiny fraction of overall American water consumption, on the order of about 1 percent. Thermoelectric power (e.g., steam-driven electric turbines) accounts for 41 percent of all water use, while irrigation for crops eats up another 37 percent.

As part of its report, the USGS published this nifty map, breaking down the different water use categories at the county level.

USGS