Summary of USGS Water-Use statistics for US counties from 1985 to 2015.

All volume flux units in km3/year, population in persons

Target fields are Population and TotalUses for each category of Domestic, Industrial, Livestock, and Irrigation.
Several fields need to be calculated from other fields for specific years.

Population, DomesticSelf Supply, Domestic Self Supply population, Public Supply population, PublicSupply Use, Industrial Self Supply, Irrigation Total Use, and Livestock Total Use are all read directly from USGS tables.

Domestic Total Use:
2005,2010, 2015: Read directly

2000: Domsetic Self Supply + <calculated> Domestic Public Delivered

Domestic Public Delivered:
1985,1990,1995,2005,2010,2015: Read directly
2000: ( Public Supply Pop (2000) * ( PublicSupplyUse (1995)+PublicSupplyUse (2005))/(PublicSupplyPop(1995)+PublicSupplyPop(2005)))  [1]

Industrial Total Use:
1985,1990,1995: Read directly
1985,1990,1995: sum of total industrial and total commercial. [2]
2000, 2005, 2010, 2015: Industrial Self Supply + max(Public Supply Use - Domestic Public Delivered, 0.0)

Notes:
[1] - Assumes that county-wide total Domestic PublicSupply is properly captured by the Population served in the year 2000, and a per-capita PublicSupply rate estimated by the average of such available data from years 1995 and 2005.
[2] - The commercial classification stopped in 2000.  Assumes that commercial is best suited to be considered industrial supply.  By grouping the uses such, some counties show non-smooth trends in both Domestic and Industrial water uses suggesting that this assumption is not uniformly valid in all counties.

Citations:

Dieter, C.A., Maupin, M.A., Caldwell, R.R., Harris, M.A., Ivahnenko, T.I., Lovelace, J.K., Barber, N.L., Linsey, K.S., 2018. Estimated use of water in the United States in 2015 (USGS Numbered Series No. 1441), Circular. U.S. Geological Survey, Reston, VA.

Maupin, M.A., Kenny, J.F., Hutson, S.S., Lovelace, J.K., Barber, N.L., Linsey, K.S., 2014. Estimated use of water in the United States in 2010, Circular. U.S. Geological Survey, Reston, Virginia.