New Record Low Stream Flow for the Spring Creek Watershed on Saturday, June 2, 2001.

by Todd Giddings, Ph.D., P.G.

    In spite receiving .79 inches of rainfall on June 2, Spring Creek in Centre County set a new 34 year record for low flow.  The red dot in the center of the Pennsylvania map below indicates that the flow of Spring Creek at the Milesburg Stream Gage set a new 34 year record low flow for June 2.  This map is from the U.S. Geological Survey Web site, and is located in the Real Time Data for Pennsylvania Section.

    Notice that no other streams adjacent to Center County are experiencing low flows.  All of the surrounding dots are green , indicating that their flows are in the 25 to 75 percentiles.  This percentile range includes normal flows.

Explanation New record high for day > 90th percentile 75th - 89th percentile 25th - 74th percentile 10th - 24th percentile < 10th percentile New record low for day Not ranked

The colored dots on this map depict streamflow conditions as a percentile, which is computed from the period of record for the current day of the year. Only stations with at least 30 years of record are used. The gray circles indicate other stations that were not ranked in percentiles either because they have fewer than 30 years of record or because they report parameters other than streamflow. Some stations, for example, measure stage only.

    This hydrograph is also from the U.S. Geological Survey Web site, and is located in the Real Time Data for Pennsylvania Section.  The new record low flow for June 2 is 158 cubic feet per second (cfs), where 1 cfs = 449 gallons per minute (gpm).  The flow was 70,942 gpm.  This record low flow is a direct consequence of the below normal precipitation received in the Spring Creek Watershed during 2000 and during 2001 year-to-date.  As of June 2, 2001 is ranked 103 out of 106 years of precipitation record at the Penn State Weather Station, with the wettest year ranked 1 and the driest year ranked 106.  A graph of the monthly precipitation for the last three years compared to the average (normal) precipitation for each month is located on The Invisible Drought page.

    Notice that the streamflow (blue line) has been consistently below the median daily streamflow (maroon triangles) based on 34 years of record for this gage.  The median daily streamflow is the middle-most value, with 17 daily streamflow values lying above and 17 lying below this median value.

    This stream gage has been operated by the U.S. Geological Survey since it was installed on May 1, 1967.  There are 34 years of stream flow record for this gage.  Graphs and tables of these streamflow data are available at the U.S. Geological Survey Web site.  A hydrograph of the last 365 days for the Milesburg gage is available by clicking here.  The lack of precipitation and ground-water recharge during last winter caused the daily streamflow (blue line) to be below the median daily streamflow line (maroon line).