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

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

Perspective

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

Competition for water can be regional too

Hydrology and Ecology — A Missing New Link

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?

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 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

What is Water Use?

Detroit land cover change 1905-1992

Changes in land cover affect: recharge streamflow wetlands water 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

Great Lakes Compact

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

Michigan’s Water Withdrawal Assessment Tool and Process

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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

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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 Curves

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

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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 Conservation

The effect matters, not the amount

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