Groundwater from the Conservationist Perspective (3-D Geographic)

NOTE: The interactive map features are currently under revision.

Click the button below to load an interactive map for groundwater resources in Spring Creek Watershed. After you click the button, a small window will appear and then a second larger window. Be sure to wait until all the maps have been loaded into this second window. If you get an error message when you try to load the map or if the maps are not in color, close both map windows and try again.

The table below lists the flow for the Big Hollow subsurface tributary and the other springs in the watershed.

Spring Creek Spring and Subsurface Drainage

Use the identify button in the groundwater GIS to find each of these springs. If you forget how to use a button, click the ? button or check out the description of the GIS on the runoff from the conservationist perspective web page.

Notice the groundwater drainage area is larger than the surface drainage. The surface drainage is determined by the land surface topography. The subsurface drainage is a function of the geology. Below are two maps and a table showing and describing the subsurface geology and its effect on water movement.

Date Source: Charles R. Wood Summary ground-water resources of Centre County, Pennsylvania prepared by the U.S. Geological Survey, Water Resources Division, in cooperation with the Pennsylvania Geological Survey, 1980.

Hydrogeologic Environments	Topographic Position	Depth to Water Table (ft)	Response to Rainfall	Seasonal Range of Water Table Fluctuations (ft)	Predominant Rock Type
Mountain Top	Crest of Ridge	50 to 300	Slow	40	Sandstone and some Shale
Mountain Slope	Side of Ridge	0 to 50	Rapid	15	Shale and shaly Limestone
Mountain Foot	Base of Ridge	100 to 200	Immediate	40	Limestone
Artesian Upland	Low Ridge on Valley Floor	0 to 15	Slow	5	Sandstone
Valley Center Ridge	Ridge on Valley Floor	200 to 500	None	0	Sandy Dolomite and Sandstone
Valley Center Upland	Broad Valley Floor	50 to 200	Slow	30	Limestone and Dolomite
Valley Bottom / Floodplain	Floodplain or Dry Valley	0 to 100	Immediate	30	Limestone and Dolomite

Data Source: Map and Table from M. Todd Giddings Jr., Hydrologic Budget of Spring Creek Drainage Basin, Pennsylvania, Ph.D. Thesis in Geology, The Pennsylvania State University, 1974.

Notice the large Valley Center Ridge region in the second map. Precipitation that infiltrates to the groundwater in this region does not discharge to the nearest stream. Instead the groundwater flows down toward Bellefonte. Notice how most of the springs shown in the groundwater GIS Most springs are located near Bellefonte, where the geology of this region discharges the groundwater. In addition to the large flows from Big and Kelly Springs, the bottom of Logan Branch must also receive some of this discharge. This helps explain why Logan Branch has such large flows while only draining a small land area.

Studies have been done to determine a water balance for the entire Spring Creek Watershed. The table below lists the most recent effort at quantifying where the precipitation goes in the watershed.

Water Balance for Spring Creek Watershed: 1968-1994

Precipitation = Evapotranspiration + Total Runoff

Total Runoff = Direct Runoff + Baseflow

The mean column corresponds to the two equations. Notice the almost equal split of precipitation into evapotranspiration and total runoff. Also notice almost all (88%) runoff came from baseflow (groundwater flow) and not from direct runoff (surface runoff). The minimum and maximum columns list the extremes for each value. These values did not occur in the same year, so the values do not add correctly, except for the minimum runoff values.

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