Harvey Thorleifson, Ph.D. Director Minnesota Geological Survey University of Minnesota

Harvey Thorleifson, Ph.D. Director Minnesota Geological Survey University of Minnesota  Information Systems Required to Ensure Sustainable Groundwater Supply

Harvey Thorleifson, Ph.D. Director Minnesota Geological Survey University of Minnesota  Information Systems Required to Ensure Sustainable Groundwater Supply

USGS Groundwater

EC

IMPORTANCE OF GROUNDWATER FOR CANADA Domestic, 43% Industry, 14% Agriculture, 43% Groundwater Use in Canada

USGS - not recharged locally - Groundwater

Surface water and groundwater systems are linked; much to most river flow is groundwater Groundwater pumping USGS

Threats to groundwater quality Vulnerability and fate of contaminants are governed by geology

Groundwater contaminant plume USGS

Role of groundwater Principal drinking water source Principal source of irrigation water Critical water supply for industry Principal usable freshwater reserve Source of water for wetlands & streamflow

Sustainable groundwater use “development and use of groundwater in a manner that can be maintained for an indefinite time without causing unacceptable environmental, economic, or social consequences” – United States Geological Survey

Sustainable pumping rates

Observation Wells

Unsustainable pumping rates

CLIMATE CHANGE NGDC

Saltwater intrusion USGS

Land subsidence

Groundwater sustainability priorities sustainable long-term yields maintenance of river flow effective use of stored water preservation of water quality preservation of aquatic environments

Sustainable groundwater management We need to balance  groundwater pumping and land use activity with  maintaining groundwater quality and quantity What do we need to do to achieve this?

Requirements for sustainable groundwater development protect recharge protect recharge minimize contamination minimize contamination manage pumping manage pumping

Indicators for sustainable groundwater development quantity quantity quality quality mapping of groundwater systems mapping of groundwater systems

County Atlas - Regional Assessment Program

Assessing the sustainability of a regional groundwater system Assessing the sustainability of a regional groundwater system Winnipeg Winnipeg

MWRB

Drillhole data

Water Chemistry Carbonate Aquifer 771 Sandstone Aquifer 206

Density; kg/m3; from chloride

Transmissivity Lake Winnipeg Lake Manitoba

Non-industrial Pumping Wells Lake Winnipeg

Flow Calibration: 1920 RMS = 7.22 m Slope = 0.92 Intercept = 23.6 R 2 = 0.75

Flow History Match: 1999 data RMS = 10.4 m Slope = 1.13 Intercept = R 2 = 0.82

Changes in head at 2019, assumed increased pumping from 1999 rates

New 3D methods

Examples of major regional groundwater systems

Winnipeg Sandstone Aquifer Saline water Potable water Maathuis, H. and Thorleifson, L. H Potential impact of climate change on Prairie groundwater supplies: review of current knowledge. Saskatchewan Research Council Publication No E00, 43 p., 28 figures, three appendices. Prairie Aquifer Mapping

Outcrop Subcrop Judith River Aquifer

Buried Valley Aquifers

Winnipeg 3D aquifer map Red River Valley Red River Valley 3D aquifer mapping Fargo 3D aquifer map

Winnipeg 3D aquifer map

Fargo 3D aquifer map

USGS Groundwater

We need to: protect recharge minimize contamination manage pumping

Basic indicators Quantity Quality

Status of mapping indicators  proportion of public domain drillhole records that are digital, georeferenced, and categorized  extent of geological mapping that is detailed, consistent, comprehensive, and categorized  extent of 3D groundwater system mapping of that takes advantage of available drillhole data, geophysical surveys, and expert knowledge.

USGS - not recharged locally - Groundwater

 mapping of our groundwater systems