How valuable is water? That depends on where you are.

Water is both essential and versatile. It is critical to human and ecosystem health, necessary in many industrial processes, indispensable in food and energy production, an important vehicle for disposing of wastes, and integral to many forms of recreation.”The Marginal Economic Value of Streamflow From National Forests by Thomas C. Brown

In the last blog post, the value of groundwater was estimated by taking information on the quantity of ground water recharge by 1km grid and the quantity of water use by county and then benchmarking to the social cost of water in LA using water scarcity (inflows minus outflows).

In this post we’ve estimated the overall social value of water use by county. Taking the social value of streamflow water from a US Forestry paper(1), and using the data from the USGS Water Census on where the counties get their water from (groundwater or streamflow), we’ve estimated the Social Value of Water withdrawal per county. The following map depicts the Social Value of Water by county. Click on the map to load an interactive version – warning, the load time is a little slow.

How can this be used? Well, water (and well water) used by buildings and sites should be evaluated based on this social cost rather than its private cost.

Usually, the financial cost of water is used in decision-making. This private cost is also usually less than the social cost with the consequence that we use too much water and add to the scarcity and depletion of groundwater. By only thinking about the financial cost we are imposing costs on our thirsty neighbours.

Autocase will be using this social value of water and will help by internalizing this important externality.

1. Brown, Thomas Capnor. The marginal economic value of streamflow from national forests. Rocky Mountain Research Station, 2004. Available from: (This report estimates what changes in water runoff are worth to society using two sources of information: economic valuation studies and water market transactions.)