As water issues continue to take a backseat to climate change, new research finds groundwater depletion is causing parts of Beijing to sink by 11 centimeters (more than four inches) per year (1). This is not a unique phenomenon, Mexico City is sinking by as much as 28 centimeters per year. Our current water demands are placing huge demands on aquifers all around the world. At impact infrastructure we’ve been doing our own homework on groundwater depletion, to try and understand the sustainability of water policy across North America (we’ve only mapped the U.S. below). It’s not looking so good.

Using data from the USGS we’ve estimated (2) (3) county by county, if the United States is using its’ supply of groundwater sustainably. Everywhere on the above map that’s blue is in okay shape. Everywhere that’s not blue are varying degrees of completely not okay. Click the picture to open an interactive map on a new page. (Note that you have to be patient as the map and data take a while to load)

recharge photo

Using this information, and a paper discussing the value of groundwater recharge (4) in urban environments, we’ve estimated the value of groundwater recharge across the continental United States and Canada.

“Groundwater supplies are a valuable resource … Urbanization, by increasing demand, reducing recharge, and increasing pollution, may increase the value of groundwater resources while at the same time decreasing aquifer capacity as well as groundwater stock. This paper models optimal groundwater use and determines the stock … values …”

The values are based on the recharge rates for each county, so the more unsustainable the water use, the higher the value of recharging aquifers is. The following map shows the value of groundwater recharge for each county in the continental United States.

Click on the map to open an interactive version in a new window. (Note that you have to be patient as the map and data take a while to load)

value photo

In the next post we’ll add in the stream-flow value of water to this groundwater value to show the overall social value of water by county.

1 https://www.theguardian.com/world/2016/jun/24/beijing-has-fallen-chinas-capital-sinking-by-11cm-a-year-satellite-study-warns

2 http://water.usgs.gov/GIS/metadata/usgswrd/XML/rech48grd.xml

3 http://water.usgs.gov/watercensus/water-use.html

4 Cutter, W. Bowman. “Valuing groundwater recharge in an urban context.” Land Economics 83.2 (2007): 234-252.