Chart of the Day: Water Use per Crop (Lawn vs Agriculture)

Via Scienceline, here’s a chart showing the amount of acre-feet of water used in a year for different “crops” in the US. It’s a cumulative total, represnting just how much “lawn” there is on the country, versus all the agricultural land.

Here you go:

water use graph lawn v crops

You can see that there’s an awful lot of lawn, and its very thirsty. It’s an additional thing to think about as we discuss setbacks, lot sizes, etc. Minnesota doesn’t necessarily have water shortages, but especially for places that rely on groundwater (like many of the suburbs), keeping the lawn green is a big drain on the water supply.

The article itself goes into detail on the relationship between lawn (aka. turf grass) — coming from homes, golf courses, and parks —  and the US water supply, which varies a lot depending on region.

Bonus:

Here’s a map!

top-crop-map

4 thoughts on “Chart of the Day: Water Use per Crop (Lawn vs Agriculture)

  1. Steve Brandt

    Unfortunately, the link to the source article wasn’t working for me, so I’m left with methodological questions. But here’s a threshold question–does anyone seriously think that Minnesota has more acres in lawn than in corn, as the map suggests? I highly doubt it, unless one is considering all of the untended grass that could hardly be considered lawn, stuff like the roadside ditches and so on. Counting parks as lawn also strikes me as disingenuous, given that many acres of parks are similarly untended and unwatered, and may not even be lawn but forest or scrub. And doesn’t having that “lawn” in grass also perform the function of holding water on site so that it can percolate into the groundwater as well as feed vegetation. Corn and some other crops don’t do that absorption nearly as well.

  2. mplsjaromir

    Most agricultural in the country is not irrigated. Go to Google maps and check out western Nebraska and notice the round fields, those are irrigated. It is true that in comparison to lawns there is greater acreage of corn fields in Minnesota but little if any is irrigated.

  3. Steve Brandt

    Good point. But what percentage of what they’re calling lawn is watered? They’re going way beyond people’s yards if they’re including parks, of which only small areas ever are watered.

    1. Joseph TottenJoseph Totten

      I think these charts aren’t showing the area derived to lawns, but the water used on lawns. Acre-feet is a common measure of water for hydrology and engineering, and I read the chart as XX million acre-feet of water are used on this crop, and doesn’t concern the amount of land the crop/lawn is on, simply raw numbers of how much water the crop/lawn uses cumulatively.

      The map likewise is confusing, without a title or caption, readers are left to posit what it means.

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