Water Availability, Water Use, and the Great
Lakes Compact
Great Lakes Water Conservation Conference
Madison Wisconsin
October 18-19 2010
Jim Nicholas, Director

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

Michigan is was 8 th in population
15 th in total water use
33 rd in water use per capita
25 th in ground-water use

St. Clair River Flow —121,000 MGD
Precipitation on Lake Michigan —33,000 MGD
Evaporation from Lake Michigan —27,000 MGD
Streamflow to Lake Michigan —25,000 MGD
Chicago Diversion —2,100 MGD
Lower Peninsula Groundwater Use —700 MGD
Pfizer —32 MGD
Lansing BWL —20 MGD
Agricultural Irrigation Well —1 MGD
Nestle Waters/Ice Mountain —0.36 MGD

Regional abundance gives us our landscape
Makes our lakes Great. Streams too.
But says nothing about how much water is available for human use.

Regional abundance does not mean a lack of local shortages or competing uses
…consider total assets and cash flow

Hydrology 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?

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)

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 Water
A Single Resource

Water Use —Effects on Distribution
Pumping from Deep Bedrock Aquifer in SE Wisconsin
Reduced flow to
Lake MI —8%
Induced flow from Lake
MI —4%
Reduced
Storage —11%
Induced GW flow from outside area —18%
Reduced flow to
SW —59%
Sources of Water to Wells

Changes in land cover affect: recharge streamflow wetlands water quality

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

•
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 waterdependent natural resources in streams
•
Process designed to ensure proposed withdrawals are legal —with burden on proposer

•
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

Response Curves predict how characteristic fishes will respond to changes in index flow

•
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?

The effect matters, not the amount

Conservation is a state of harmony between men and land —Aldo Leopold