Water Well Journal
Issue link: http://read.dmtmag.com/i/465664
A ccording to U.S. Geological Survey estimates released in November 2014, daily groundwater withdrawals declined 0.42% between 2005 and 2010, continuing a decline that began with estimates in 2000. The USGS estimates the nation pumps 79.3 billion gallons per day (BGD) of fresh 1 groundwater for all purposes, down from the 79.6 BGD in the 2005 estimate and the 83.3 BGD in the Survey's 2000 estimate. The USGS compiles these estimates every five years. As an estimated percentage of the nation's total water sup- ply, groundwater dropped slightly from 26% in 2005 to just under 25% in 2010. While less than in 2005, the 2010 ground- water estimate is nearly 17% higher than the Survey's 1970 estimate. While overall 2010 fresh groundwater abstraction volume estimates were down slightly from 2005, some categorical changes are notable. Irrigation Leads the Way As always, irrigation is the largest abstraction of ground- water in the United States, some 49.5 BGD in 2010, but a de- crease of 7.5% from 2005's 53.5 BGD, and a 14.7% decline from 2000. The top five states as measured by volume of abstractions for irrigation are: California (8.69 BGD), Arkansas (7.38 BGD), Nebraska (5.3 BGD), Texas (5.1 BGD), and Kansas (2.88 BGD). States with notable increases in gallons abstracted between 2005 and 2010 were: Mississippi with a 530 million gallons per day (MGD) increase (37.06%) to 1.96 BGD, Arkansas (360 MGD more to 7.38 BGD), Kansas (260 MGD increase), Washington (169 MGD more), Georgia (150 MGD increase), and Florida (130 MGD increase). States with notable volume declines in irrigation abstrac- tions were: Nebraska's drop to 4.3 BGD from 7.3 BGD (–41.2%), Colorado's and Texas' 1.02 BGD declines, and Arizona's 570 MGD reduction. Groundwater abstractions in 2010 for domestic use, essen- tially private household wells, were an estimated 3.54 BGD, a decline of 7.6% from 2005, but nearly on par with the estimated 3.592 BGD of 2000. Major domestic withdrawal states in 2010 were: Texas (259 MGD), North Carolina (231 MGD), New York (231 MGD), Florida (214 MGD), and Pennsylvania (201 MGD). States experiencing the most significant increases in esti- mated withdrawal amounts were: Delaware, from 6.43 MGD to 14.8 MGD, a 130.2% increase; North Carolina, up 43.5%; Wyoming, up 35.3% to 8.6 MGD; Pennsylvania, up 32.2%; and Rhode Island, up 31.5% to 8.02 MGD. States with the most significant percentage decreases in estimated withdrawal amounts were: Hawaii, down 84.8% to 1.85 MGD; North Dakota, down 58.7% to 3.68 MGD; Kentucky, down 43.4% to 19.7%; Utah down 38.3% to 8.44 MGD; and South Dakota down 30% to 5.37 MGD. Public Supply Use Increases Water Well Journal reported in its November 2014 issue a U.S. Census measured decline in newly constructed single family houses served by individual well systems from 12.1% market share in 2009 to 8.4% share in 2013. Public supply groundwater abstractions in 2010—15.7 BGD—were 7.6% higher than the 2005 estimates, but were about equal to the 15.98 BGD of 2000. As a segment of the nation's total groundwater withdrawals, the public water supply use rose to just below 21%. California's estimates for this market segment were up 121% from 2005 to 2.83 BGD. California's is the largest estimate for this category, with Florida following behind in second with 2.01 BGD, and Texas is third with 1.13 BGD. Between 2005 and 2010 reporting, there was a decline of 209 community water systems using groundwater—a change of just 0.5%, at least as tabulated by the U.S. Environmental Protection Agency. The population served groundwater by those systems also decreased by 1.17 million, or just slightly more than 1%. Connecticut recorded an increase of 77.4% to some 135 MGD, while abstractions in Oregon were up 40.9% from 2005 to an estimated 114 MGD. Other states with notable increases were Colorado (27.4%), North Carolina (24.4%), and Missouri (20.6%). States with notable decreases in groundwater abstractions for public supply include South Carolina's 24.5% decline to ESTIMATED GROUNDWATER USE IN 2010 IN THE UNITED STATES Withdrawals of groundwater declined, continuing a trend beginning in 2000. By Kevin McCray, CAE GROUNDWATER USE continues on page 30 Twitter @WaterWellJournl WWJ March 2015 29 1 Numbers reported in this article are for fresh withdrawals. Saline withdrawals are estimated by the Survey as well. Groundwater abstractions in 2010 for domestic use, essentially private household wells, were an estimated 3.54 BGD, a decline of 7.6% from 2005.