Groundwater | Trends
Summary
Groundwater storage in the northern part of the state has been decreasing over the last 30 water years, while increasing in the southern part of the state. The annual average water table is decreasing, which means that groundwater is getting further from the ground surface, for 53% of monitoring wells, with three decreasing significantly. Four locations are increasing significantly, but in general the magnitude of the decreasing trends is larger than that for the increasing trends. Similar distribution of trends can be seen in the maximum water table height with 59% of locations experiencing decreases dominating in the north. The range is also increasing the same parts of the state as the difference between the seasonal high and low water table increases.
The Groundwater Trends webmap displays the results of statistical trend analysis over the last 30 years of groundwater measurements from groundwater monitoring sites within the state of Indiana. Trends for several water level metrics are available for viewing through the interactive map. Descriptions of the various metrics presented in the webmap can be found at the bottom of this page.
Click Here to Open Interactive Long-Term Trends Webmap
Layers Present in Webmap
Rate of Change of Mean Water Table [in/yr] – The rate of change of the annual mean water level over the last 30 years based on the Theil-Sen trend slope estimator. An increasing trend indicates a rising water table although the depth to the water table is decreasing. Statistically significant trends were identified based on a 10% significance level using the Mann-Kendall statistical test.
Rate of Change of Maximum Water Table [in/yr] – The rate of change of the annual maximum water level over the last 30 years based on the Theil-Sen trend slope estimator. An increasing trend indicates a rising water table although the depth to the water table is decreasing. Statistically significant trends were identified based on a 10% significance level using the Mann-Kendall statistical test.
Rate of Change of Minimum Water Table [in/yr] – The rate of change of the annual minimum water level over the last 30 years based on the Theil-Sen trend slope estimator. An increasing trend indicates a rising water table although the depth to the water table is decreasing. Statistically significant trends were identified based on a 10% significance level using the Mann-Kendall statistical test.
Rate of Change of Water Table Range [in/yr] – The rate of change of the annual water level range over the last 30 years based on the Theil-Sen trend slope estimator. An increasing trend indicates a rising water table although the depth to the water table is decreasing. Statistically significant trends were identified based on a 10% significance level using the Mann-Kendall statistical test.