U.S. Department of the Interior U.S. Geological Survey Water Availability, Water Use, and the Great Lakes Compact Jim Nicholas, Director USGS Water Science Center Lansing, Michigan Great Lakes Water Conservation Conference Madison Wisconsin October 18-19 2010
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U.S. Department of the Interior U.S. Geological Survey Water Availability, Water Use, and the Great Lakes Compact Jim Nicholas, Director USGS Water Science.
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U.S. Department of the InteriorU.S. Geological Survey
Water Availability, Water Use, and the Great Lakes Compact
Jim Nicholas, DirectorUSGS Water Science CenterLansing, Michigan
Great Lakes Water Conservation ConferenceMadison Wisconsin October 18-19 2010
Abundance of Water
20 percent of world’s fresh surface water
800,000,000,000,000 cubic feet
Regional bedrock aquifers
Glacial aquifers > 1000-ft thick
100,000,000,000,000 cubic feet
Water Use in Michigan
Michigan is was 8th in population
15th in total water use
33rd in water use per capita
25th in ground-water use
PerspectiveSt. Clair River Flow—121,000 MGDPrecipitation on Lake Michigan—33,000 MGD Evaporation from Lake Michigan—27,000 MGDStreamflow to Lake Michigan—25,000 MGD
But says nothing about how much water is available for human use.
Regional abundance does not mean a lack of local shortagesor competing uses
…consider total assets and cash flow
Competition for water can be regional too
Hydrology and Ecology—A Missing New LinkHydrology is a principal driver of aquatic
ecology
Hydrologists know little ecology and Ecologists know little hydrology
Aquatic ecosystems are a focus of most water availability discussions
How much water do we need to leave in the stream?
There is No Unused Water
All water is being used by someone or something Humans change what the water is being used for
All human use of water has an effect on someone or something—often local
Often the effect is not noticeable or is perceived to be outweighed by a benefit (Chicago Diversion)
There is No Unused Water
Human uses of water redistribute water in time and place
A dam may alter the high and low flows of a river
A city with an intake in a Great Lake may discharge used water to a stream that is tributary to the lake
A groundwater use will always have an effect on a surface-water body, though the effect may be too small to measure
Groundwater –Surface WaterA Single Resource
Water Use—Effects on Distribution
Reduced flow to SW—59%
Induced GW flow from outside area—18%
Reduced Storage—11%
Reduced flow to Lake MI—8% Induced flow
from Lake MI—4%
Pumping from Deep Bedrock Aquifer in SE Wisconsin
Sources of Water to Wells
What is Water Use?Detroit land cover change 1905-1992
Changes in land cover affect:
rechargestreamflowwetlandswater quality
What is Water Use?Drain Tiles
Lower water tables
Less recharge
Faster movement to streams
Fewer wetlands
More useable land
Does the amount of a water use matter or just the IMPACT of the use:
changing where water goes, when it goes there, and its quality
Withdrawals and Consumptive Uses:
…no significant individual or cumulative adverse impacts to the quantity or quality of the Waters and Water Dependent Natural Resources of the Watershed
Great Lakes Compact
Michigan’s Water Withdrawal Assessment Tool and Process
• Assist Michigan in implementation of the Great Lakes-St. Lawrence River Basin Compact and Agreement
• Michigan legislation defines and prohibits Adverse Resource Impacts (ARI) to water-dependent natural resources in streams
• Process designed to ensure proposed withdrawals are legal—with burden on proposer
WWAT—Three Models• Flow—How much water is in the stream?
• Withdrawal—How much will a proposed withdrawal reduce streamflow?
• Fish—How will reduced streamflow affect fish?
The WWAT evaluates the impact of the water use, not the amount.
If the impact is not “adverse”, then it is ok
Ecological Response CurvesResponse Curves predict how characteristic fishes will respond to changes in index flow
Development of WWAT• Compact and Michigan Legislation provided
the need to define “adverse” resource impact
• Science provided the context within which to define “adverse”
• State government made policy definition of “adverse”
• Water Resource Conservation Advisory Council provided a collaborative context for policy makers and scientists to iteratively inform each other
Does the amount of a water use matter or just the IMPACT of the use:changing where water goes, when it goes there, and its quality
…then is water conservation also is more than just the amount conserved? Isn’t it about the IMPACT of the conservation?
Water Use and ConservationThe effect matters, not the amount
Conservation is a state of harmony between men and land—Aldo Leopold