Cretaceous Aquifer
The Cretaceous aquifer system is in the oldest sediments deposited in the Coastal Plain of Georgia (Clarke and Pierce, 1985). The aquifer system is a southwest-northeast trending belt about 50 miles wide that runs from Columbus to Augusta, Georgia, along the southern boundary of the Piedmont Province. This aquifer is highly productive, second in Georgia only to the Upper Floridan (Pollard and Vorhis, 1980). During 2015, about 166.4 million gallons per day (Mgal/d) were withdrawn from the Cretaceous aquifer in Georgia, primarily for public supply, irrigation, and industrial uses (Painter, 2019). The Cretaceous aquifers include the Providence Sand, Cusseta Sand, and Tuscaloosa in west Georgia, and the Dublin and Midville in east Georgia.
The Cretaceous aquifer is informally divided into two areas for discussion of water levels. The southwestern and central Georgia area has 10 wells that continuously monitor water levels. Richmond County in east Georgia has 6 wells that continuously monitor water levels.
Cretaceous Aquifer: Central and Southwestern Georgia
Aquifer Characteristics: Water levels in 10 wells in the Cretaceous aquifer system were used to define groundwater conditions throughout central and southwestern Georgia (excluding the Augusta/Richmond County area). In this area, water in the Cretaceous aquifer system mostly is confined (under pressure by overlying sediments) but can be unconfined (in contact with the atmosphere) in stream valleys or the out-crop area near the southern boundary of the Piedmont. Hydrographs show periodic upward or downward trends that largely reflect changes in pumping and long-term, multi-year wet and dry periods.
Well Locations with Ten Year Trend Icons
Arrow icons represent upward or downward water-level trend. Water-level trend calculations based on last 10 years of data.
Circle icon represents slope of trend line with an absolute value that is less than 0.01 feet per year (ft/yr), based on last 10 years of data.
Split color icons represent wells with graphs.
Light blue square indicates nearby precipitation gage.
Diamond icon represents less than 100 monthly-mean water levels from the last 10 years of data.
(Click or hover over map icons for more information.)
Water-level Trends: The table below shows the period of record (POR) and most recent ten-year trends of monthly mean water levels for ten Cretaceous-aquifer wells. The data used in the trend analyses are pulled from the USGS National Water Information System: Web Interface (NWISweb), and the trends are calculated in ft/yr. The check boxes on the left side of the table allow the reader to compare only those wells of interest by selecting them on or off to appear on the Monthly Mean Composite Graph. Water levels in most wells in the Cretaceous aquifer have been declining since the 1970s.
Below the table and composite graphs are trend analysis graphs for three selected wells. The trend analyses show mostly long-term effects of pumping. A simple regression line may be placed on the graph by selecting the Simple Regression button, and the slope of the line is calculated. To clear the regression line, select the Clear Regression Line button. Like the composite graph, the user can click and drag the mouse vertically or horizontally to change the scale and zoom in to the time-period of interest. Any changes to the time scale will require the user to clear and recreate a regression line for the new time scale. Double click on the graph and it will return to the period of record.
Period of Record (POR) and Previous Calendar Year Summary Table
| Well | Period of Record | Previous Calendar Year |
|---|---|---|
| Mean of monthly water levels in feet below land surface | Monthly mean water levels in feet below land surface | |
| 28X001 | xxxx | xxxx |
| 12L021 | xxxx | xxxx |
| 06S001 | xxxx | xxxx |
Period of Record (POR) and Previous Calendar Year Table, updated weekly. Monthly Mean Composite graph updated weekly, all other graphs and tables continuously updated. Negative depths to water indicate water level in feet above land surface.
Slope of trend line for Period of Record (POR) and previous Ten Years
Station Name Data Link |
County |
Water-bearing Unit1 |
POR First Month/Year |
POR slope (ft/yr) |
Ten Year slope (ft/yr) |
|---|---|---|---|---|---|
| Burke | M | xx | xx | yy | |
| Burke | LM | xx | xx | yy | |
| Burke | LD | xx | xx | yy | |
| Dougherty | P | xx | xx | yy | |
| Johnson | M | xx | xx | yy | |
| Laurens | M | xx | xx | yy | |
| Muscogee | T | xx | xx | yy | |
| Pulaski | M | xx | xx | yy | |
| Twiggs | D | xx | xx | yy | |
| Washington | DM | xx | xx | yy |
1M, Midville aquifer system; LM, lower Midville aquifer; LD, lower Dublin aquifer; P, Providence aquifer; T, Tuscaloosa Formation;D, Dublin aquifer system; DM, Dublin-Midville aquifer system. Slope of 0.00 represents no trend.
Monthly Mean Composite Graph
To change the graph scale, click and drag mouse vertically or horizontally.
To reset the graph scale, double click on the graph.
Blank where data are missing.
(mouse over graph for date and depth)
Select Monthly Mean Data Graphs with Trend Analysis
To change the graph scale, click and drag mouse vertically or horizontally. To reset graph scale, double click on the graph. Blank where data are missing.