Groundwater in the Great Lakes Basin

Estimates of the Level and Extent of Consumptive
Groundwater Use
Recent Research
Water resource planners and managers want to know
the amount of consumptive water use in the Great
Lakes Basin to help understand the impact of human
use of water on the hydrologic system. Consumptive
use is water that is evaporated, transpired or incorporated
into products or crops; consumed by humans or
livestock; or otherwise removed from an immediate
water environment (water body, surface or groundwater
source, basin). When water is consumed and
unavailable for use, interest increases in measures to
document current levels of consumptive use and to
develop policies that will optimize the use and reuse of
water as much as possible.
The Great Lakes Commission compiles water-use and
consumptive-use data provided by the Great Lakes
jurisdictions. Water use during 2002 and consumptive-use
data by water-use category are the most recent
basinwide information available. The consumptive-use
estimates are computed by using consumptive-use
coefficients. Preliminary discussions with state
agencies indicated that refinement of consumptive-use
data and coefficients is an area of great interest and
value to water-supply managers (Grannemann and
Reeves, 2005). The USGS is working on two reports
on consumptive-use coefficients. This first, by Shaffer
and Runkle (2007), is a compilation of consumptiveuse
coefficients by water-use categories. That report
contains:
• An annotated bibliography of references with
consumptive-use coefficients
• An appendix with detailed consumptive-use coefficient
tables from selected references
• Consumptive-use coefficients for domestic and
public-supply, industrial (including industrial
use by major standard industrial classification
codes), thermoelectric power, irrigation, livestock,
commercial and mining water-use categories
• A selected statistical analysis
• Summary tables by geographical area and wateruse
category for the Great Lakes Basin and areas
climatically similar to the basin, plus selected references
for elsewhere in the world
The statistical analysis (Kimberly Shaffer, written
communication) includes the median and the 25 th and
75 th percentiles of consumptive-use coefficients by
water-use category and provides a starting point for
facilities managers, water managers and scientists to
compute water consumption and return flow.
The second consumptive water-use report compares
the consumptive-use coefficient statistics (median
and 25 th and 75 th percentiles) computed by Shaffer
and Runkle (2007) to consumptive-use coefficients
computed from monthly water-use and return-flow
data for Ohio as well as monthly water-use data for
Indiana and Wisconsin (public supply only). That
report also analyzes the monthly water-use data to
determine if there is monthly variability in consumptive
use and consumptive-use coefficients by water-use
category.
Recommended Future Research
Water-use analysis is becoming more important as
stresses on water resources increase. Additional work
on consumptive water use is especially important to
future water resources development. New estimates
of consumptive use by water-use sector such as irrigation,
municipal use, domestic use and industrial use are
needed to more fully understand the impact of groundwater
withdrawals in the Great Lakes Basin.
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