Dry weather across central Illinois this year has lowered Lake Springfield’s level, but conditions remain just below normal for this time of year due to some amount of rainfall and a handful of days of water being available from the South Fork of the Sangamon River to pump in.
As of October 30, the lake level is 557.50 feet above sea level—2.5 feet below full pool (560 feet) and about 0.68 feet below the 75-year average for October. This is consistent with typical fall conditions following a hot summer and reduced rainfall. The lake’s primary feeds are Sugar and Lick Creeks, which can slow to a trickle during dry periods.
Seasonal Trends
Lake Springfield’s highest levels usually occur in spring after heavy rains, while the lowest are seen in fall and early winter after hot temps and the outdoor watering season has concluded.
Anytime lake levels fall and under the utility’s Drought Management Plan, the Water Plant supplements the lake by pumping in water from the South Fork of the Sangamon River. This pump station went into operation in 1955 following a 3-year severe drought when Lake Springfield’s level dropped by over 12.5 feet. This year there were only 5 days where water was available to pump water in from the South Fork of the Sangamon River.
At the current lake level and for this time of year, CWLP continues routine operations, with no restrictions or conservation requirements for customers. The lake level and weather forecasts are closely monitored for conservation readiness should a drought persist and winter and spring precipitation be lacking.
Winter & Summer Operations
Each fall around mid-November, CWLP transitions the lake to winter operations, which dictates targeting a lake level of 559.60 feet by release of water over the dam to protect docks and shoreline structures from ice and wave damage. Since the current lake level is under the winter operations target, no water release is necessary.
For summer operations, Lake Springfield begins a target elevation of just over full pool, 560.50 feet each spring.
Historical Perspective
Lake Springfield has experienced much greater extremes in its history—from a record high lake level of 564.50 feet in April 1994 to a record low of 547.44 feet in December 1954 during a severe drought.
