David P. Lusch, Ph.D. 1 / 14 David P. Lusch, Ph.D. Distinguished Senior Research Specialist Michigan State University Dept. of Geography, Remote Sensing & GIS Research and Outreach Services Group Institute of Water Research Michigan’s Water Withdrawal Assessment Process and Using the WWA Tool for Planning and Watershed Management and

David P. Lusch, Ph.D. 2 / 14 Michigan’s Water Withdrawal Assessment Process for Planning and Watershed Management The Great Lakes Compact: why Michigan is regulating large-quantity water withdrawals Brief review of Michigan Water Law Tutorial on some key hydrologic terms and concepts

David P. Lusch, Ph.D. 3 / 14 Sources of Water in Rivers –Overland Flow –Baseflow (i.e., groundwater discharge) –Interflow –Direct precipitation in channel Michigan’s Water Withdrawal Assessment Process for Planning and Watershed Management

David P. Lusch, Ph.D. 4 / 14 Sources of Water in Rivers Precipitation ET Groundwater flow path Soil Moisture Infiltration Overland Flow (runoff) Interflow Water table Michigan’s Water Withdrawal Assessment Process for Planning and Watershed Management

David P. Lusch, Ph.D. 5 / 14 Baseflow of a river − the amount of groundwater that discharges from an aquifer into the watercourse. − Baseflow occurs year-round, but fluctuates seasonally depending on the level of the water-table aquifer. − The baseflow of a river is supplemented by direct runoff during and immediately after precipitation or snowmelt events. Michigan’s Water Withdrawal Assessment Process for Planning and Watershed Management

David P. Lusch, Ph.D. 6 / 14 Runoff dominated river – very little baseflow: “flashy” and warm Intermediate river – baseflow + runoff: warm/cool, but fewer extremes Baseflow dominated river – very little runoff – cold/cold transitional Michigan’s Water Withdrawal Assessment Process for Planning and Watershed Management

David P. Lusch, Ph.D. 7 / 14 Index Flow – the flow that is met or exceeded 50% of the time for the lowest summer flow month of the flow regime, determined over the period of record or extrapolated from USGS flow gauges in Michigan. Michigan’s Water Withdrawal Assessment Process for Planning and Watershed Management

David P. Lusch, Ph.D. 8 / 14 Groundwater Withdrawal Impacts on Rivers –Reduced flow –Altered water temperatures Michigan’s Water Withdrawal Assessment Process for Planning and Watershed Management

David P. Lusch, Ph.D. 9 / 14 GW Withdrawal Impacts on Rivers Precipitation ET Groundwater Flow - COLD Soil Moisture Runoff - WARM Interflow Water table Reduced Baseflow Michigan’s Water Withdrawal Assessment Process for Planning and Watershed Management

David P. Lusch, Ph.D. 10 / 14 Pumping well water sources –Initially, water is removed from storage in the aquifer, and the head near the well is reduced inducing flow towards the well. –As water is removed from storage, a cone of depression forms around the well. Michigan’s Water Withdrawal Assessment Process for Planning and Watershed Management

David P. Lusch, Ph.D. 11 / 14 Pumping well water sources –In most cases, the cone of depression continues to expand until the pumpage is balanced by a decrease in discharge from the system, resulting from the lowered head in the system which decreases the flow gradient in discharge areas and may shift the groundwater divide. –The change in discharge due to pumping is called “capture.” Michigan’s Water Withdrawal Assessment Process for Planning and Watershed Management

David P. Lusch, Ph.D. 12 / 14 Michigan’s Water Withdrawal Assessment Process for Planning and Watershed Management Source of water to a pumping well Decrease in the discharge from the system, resulting from the lowered head in the system, decreased gradients in discharge areas and shifts in the groundwater divide. Ground-water divide Ground-water divide Cone of depression Q 2 > Q 1 gaining stream gains less losing stream

David P. Lusch, Ph.D. 13 / 14 Michigan’s Water Withdrawal Assessment Process for Planning and Watershed Management Source of water to a pumping well

David P. Lusch, Ph.D. 14 / 14 The next segment –Water Withdrawal Tool Science Michigan’s Water Withdrawal Assessment Process for Planning and Watershed Management