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Statewide Aquifer Mapping
Project Overview
(SAMP)
The statewide aquifer mapping project began in March 1997 and was completed in March 2000. The goal of the project was to delineate aquifer boundaries, quantify yields, develop a standardized naming system, and define aquifer thickness for all of the significant aquifers in the state. Prior to the initiation of this project, the State of Ohio did not have a statewide aquifer map for unconsolidated (glacial) or bedrock aquifers, and had no formal identification system for aquifer boundaries, types, or names. Partial funding for the project was provided by a grant obtained from the United States Environmental Protection Agency under Section 319 of the Clean Water Act.
About the Unconsolidated
Aquifer Mapping Component
Data Sources
As with the bedrock aquifer maps, the draft unconsolidated aquifer maps are constructed on a standard 7.5 minute USGS quadrangle base. Data sources include maps, reports, and drilling logs from a variety of public and private organizations.
Aquifer Naming Conventions
Individual aquifers receive a two-part name. The first portion of the name identifies the local area where the aquifer exists, and the second part of the name identifies the fundamental type (hydrogeologic setting) of aquifer. For example, the Mad River Buried Valley Aquifer is present underneath and adjacent to the Mad River in southwest Ohio, and the aquifer belongs to the "buried valley" type. Ten different aquifer types (hydrogeologic settings) are used in this methodology: buried valley, ground moraine, end moraine, lacustrine, thin upland, alluvial, beach ridge, outwash/kame, thick drift complex, and valley fill.
Unconsolidated Data File Format
Polygon Coverages are in ArcInfo export file format and as ArcView shape files.
Methodology
The mapping methodology for the glacial aquifer maps varies somewhat from the bedrock aquifer maps. Few individual units have been formally named; therefore, aquifer boundaries were mapped using the lithologies (e.g. till, silt, sand, gravel, etc.) present. Primary lithologies are listed in capital letters, secondary lithologies are listed in lower case. For example, the designation Tsg indicates till with sand and gravel lenses. The complex nature of glacial deposits does not allow mapping multiple distinct aquifers at most locations.
Yields are divided into five categories: 0-5 gallons per minute (gpm), 5 -25 gpm, 25-100 gpm, 100-500 gpm, and greater than 500 gpm. Aquifer thicknesses fall into one of three categories: less than 25 feet, 25 to 100 feet, and greater than 100 feet.
Individual 7.5 minute quadrangle maps have been compiled into a single statewide ArcInfo coverage. This coverage is available for download from this site.
Authors
| Mapping: |
Mike Angle, Frank Fugitt, Paul Spahr |
| GIS: |
Paul Spahr, Ken Pendley, University of Dayton
(w/ support of Miami Conservancy District) |
| Project Management: |
Mike Angle, Mike Hallfrisch, Ted Lozier |
About the Bedrock
Aquifer Mapping Component
Data Sources
Aquifer delineations were completed at a scale of 1:24,000, using standard USGS 7.5 minute quadrangles as a base. Data for constructing the maps came from geologic and hydrogeologic maps, reports, and test well data published by the ODNR Division of Water, ODNR Division of Geological Survey, the United States Geological Survey, and other public and private organizations.
Aquifer Naming Conventions
The naming convention was based on the naming system used by the ODNR Division of Geological Survey for the reconnaissance bedrock geology maps. For example, the bedrock unit named Berea Sandstone by the ODNR Division of Geological Survey is the Berea Sandstone aquifer. In some cases, formations identified by the ODNR Division of Geological Survey have been grouped into a single aquifer because these formations contain similar lithology and water-bearing properties. In other cases, important aquifers have been separated from multiple formation groups mapped by the ODNR Division of Geological Survey.
Bedrock Data File Format
Polygon Coverages are in ArcInfo export file format and as ArcView Shape files.
Methodology
Bedrock aquifers were mapped as separate coverages and will overlap each other in some areas of the state. The following four attributes were assigned to each coverage: aquifer name, boundaries, thickness, and yield.
Yields for the bedrock aquifers are divided into four categories: 0-5 gallons per minute (gpm), 5 -25 gpm, 25-100 gpm, and greater than 100 gpm. Aquifer thicknesses fall into one of two categories: less than 100 feet, or greater than 100 feet. In portions of eastern and southeastern Ohio where relief is extremely high, the 100-foot thickness line was not drawn.
Completed 7.5 minute bedrock aquifer maps were digitized into the ArcInfo geographic information system (GIS) and electronically joined into statewide aquifer coverages.The areal extent, thickness, and yield of each individual aquifer exists as a series of statewide coverages within the ODNR GIS system. These coverages are available for download from this site.
Authors
| Mapping: |
Bill Haiker, Wayne Jones, Kathy Sprowls, Mike Hallfrisch |
| GIS: |
Wayne Jones, Bill Haiker, Ken Pendley |
Project
Management: |
Mike Hallfrisch, Ted Lozier |
For more information on the State Bedrock and Glacial Aquifer Mapping project, please contact:
Jim Raab at
Phone (614) 265-6747
Fax (614) 265-6767 or
E-mail at jim.raab@dnr.state.oh.us
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