Understanding Well Data

DepthMap provides access to extensive water well data from public records across the United States. This guide explains what information is available, how to interpret it, and where the data originates.

Quick Start: View Well Details

1. Click any well marker on the map
2. View basic info: ID, depth, date, owner
3. Click View Well Log for full report
4. Review formation layers and construction details
5. Use data to inform planning decisions

Key Well Data Fields

Step-by-Step Workflow

1. Click any well marker on the map
2. View basic info: ID, depth, date, owner
3. Click View Well Log for full report
4. Review formation layers and construction details
5. Use data to inform planning decisions

Data Sources

State Agencies

Well construction reports are filed with state geological surveys, environmental agencies, or water management departments. Requirements vary by state, but most require drillers to submit reports for new wells within a specified timeframe after completion.

What Gets Reported

Typical well construction reports include:

• Well location (address or coordinates)
• Property owner at time of construction
• Driller and drilling company information
• Construction date
• Total depth drilled
• Casing specifications
• Formation layers encountered
• Static water level
• Pump information
• Driller notes and observations

Data Quality

Report quality depends on original documentation practices. Some reports include detailed geological descriptions while others provide only basic construction data. Older wells may have limited information compared to recent installations.

Well Information Fields

Basic Information

• Well ID - Unique identifier assigned by the reporting agency
• Construction Date - When the well was drilled
• Total Depth - The deepest point reached during drilling
• Well Type - Purpose of the well (domestic, commercial, irrigation, etc.)

Location Data

• Address - Property address where the well is located
• GPS Coordinates - Latitude and longitude of the well
• Township/Range/Section - Legal land description (in states using PLSS)
• County - County where the well is located

Construction Details

• Casing Diameter - Width of the well casing
• Casing Depth - How deep the casing extends
• Grout Seal - Depth of annular seal around casing
• Screen Interval - Where water enters the well

Water Information

• Static Water Level - Water level when well is not pumping
• Yield - Flow rate during testing (gallons per minute)
• Water Quality Notes - Any observations about water quality

Geological Information

• Formation Log - Description of materials encountered at each depth
• Bedrock Depth - Where solid rock was encountered
• Aquifer - Water-bearing formation supplying the well

Reading Well Logs

Well logs describe what the driller encountered at different depths during construction.

Formation Descriptions

Common terms in well logs:

Depth Intervals

Formations are listed with depth ranges, such as "Sand 45-78 ft" meaning sand was encountered from 45 feet to 78 feet below surface.

Water Notes

Look for notations about where water was encountered, flow rates during drilling, and static water level measurements.

Data Coverage by State

Coverage varies significantly by state:

complete Coverage

States with extensive digital records and good historical data include Wisconsin, Minnesota, Ohio, and several others. These states often have wells dating back many decades.

Growing Coverage

Many states are actively digitizing older records and expanding their databases. Coverage improves over time as more historical data becomes available.

Limited Coverage

Some states have minimal public well records or only recent data. Rural areas may have fewer documented wells than urban regions.

Data Limitations

Not Real-Time

Well data represents conditions at the time of construction. Water levels, yields, and property ownership may have changed since the report was filed.

Location Accuracy

Older wells may have less precise location data. Some coordinates are estimated from addresses rather than GPS measurements.

Completeness

Not all wells are represented. Some private wells predate reporting requirements, and compliance with filing requirements varies.

Regional Variation

Geological conditions change across short distances. A well log from one property may not accurately predict conditions on an adjacent property.

Using Well Data Effectively

Research Best Practices

• Review multiple wells in an area to understand patterns
• Note the construction dates of wells you examine
• Consider the distance from your area of interest
• Look for consistency among nearby well logs

Planning Applications

Well data helps inform planning but should not replace professional assessment for:

• New well site selection
• Water supply evaluation
• Geological studies
• Engineering decisions

Disclaimer

Well data is sourced from public records nationwide. Data accuracy and completeness may vary by region. Always verify critical information through official channels and professional consultation.

Troubleshooting

Well log not available?

• Not all wells have digitized reports
• Some states have limited historical data
• Well may predate reporting requirements

Formation data missing?

• Older reports may have minimal detail
• Quality depends on original driller documentation
• Some wells only have basic depth information

Location seems inaccurate?

• Older wells may have estimated coordinates
• Address-based locations less precise than GPS
• Verify with additional nearby wells if possible

Related Topics

• Map Navigation - Find and search wells
• Map Layers - Toggle data layers
• Map Tools - Estimate geology
• DepthMap Overview - Features and subscription