Springfield, IL Reservoirs

The varying reports and events surrounding Lake Springfield and Hunter Lake span over fifty years and address several topics of environmental and economic concern, yet even with all this data there is no document that presents the situation in a format digestible to the general public. A major goal of this project will be aimed at fulfilling this void. Given this is an ongoing debate, if the public is to be a part of this decision-making process, they should have a relative understanding of the situation.

An Illinois State Water Survey in 1948 found that the original 20 billion gallon capacity of Lake Springfield had been reduced to 19.1 billion gallons in the span of 14 years due to sedimentation (Stall & Goffschalk, 1952). In 1985 the capacity stood at 17 billion gallons, 13% less than the original body (Knapp, 1998, p.46). From 1987-1990, the CWLP conducted a dredging project at a cost of $7.8 million, removing 3 million cubic yards of sediment and restoring 652 million gallons of capacity (Lake Springfield 1935-2010).

There has been continuous effort to try and manage the rate of sedimentation through better watershed management practices. Through the Sangamon County Soil and Water Conservation District and a Lake Springfield Watershed Project funded by the National Fish and Wildlife Foundation and the Springfield CWLP, there has been organization among farmers of the watershed to implement soil conserving practices such as no-till, cover crops, and buffer zones. In 2004 the lake was down to 16.7 billion gallon capacity, but studies show that the rate of sediment loss is lower due to better watershed management (CWLP, Lake Springfield 1935-2010).

A number of alternative water sources have been suggested to supplement Lake Springfield. These include groundwater locations in the Sangamon River Valley, the Illinois River Valley, and the Havana Lowlands. Another option is the reclaiming of water used in ash sluicing from the power plant. There is also the option to build additional reservoirs such as the Lick Creek Reservoir and the most popular and debated being Hunter Lake (Knapp, 1998, p.5-6).

Hunter Lake is the proposed damming of Horse and Brush Creek near the South Fork pump station. The second lake was first recommended in 1965 following the droughts of 1952-55 and the original sedimentation surveys. The lake was named after CWLP commissioner John Hunter. The interest in Hunter Lake has varied over the years with renewed interest following periods of drought or mandatory water conservation such as in 1988 and 2000 (CWLP, Lake Springfield 1935-2010). The first permit for the lake was submitted to the U.S. Army Corps of Engineers in 1989 with a primary purpose of supplemental water. The most reset application in 2018 suggested recreation as the primary purpose and supplemental water as the second purpose (U.S. Army Corps of Engineers).

Through change detection I had hoped to Identify the amount of land that would be inundated or altered by Hunter Lake. I was unable to classify the Hunter Lake feature layer I had created, so I performed my own makeshift change detection by classifying the entire watershed then clipping the area within the Hunter Lake feature layer. I built raster attribute tables in order to identify the number of pixels altered in each class. I found that 1,353 of 41,514 developed pixels, 8,620 of 21,942 herbaceous (forest, grassland, etc.) pixels , and 3,529 of 313,756 agricultural pixels would be lost to Hunter Lake. 39% of the herbaceous land within the watershed would be inundated. Looking at other research such as that published in a statement by the Springfield City Council found that of all the acquisition land, 3,101 acres are agricultural, 2,705 acres are forested, 1,858 are grassland, and 100 are developed. This report only claimed 1,108 acres of farmland would be inundated, and did not acknowledge the lost of forest or grassland.

10-Digit watershed boundaries obtained through the USDA data gateway, Lake Springfield and Hunter Lake watersheds were then selected and used to create layers. Landsat 8 imagery was obtained through the USGS Earth Explorer with a date of November 12, 2021 at path: 23, row: 33. The multispectral image was then clipped to the watershed polygons and classified using support vector machine. The proposed site of Hunter Lake was obtained through a scanned map by the CWLP. The map was georeferenced and traced to create a feature layer.

Future research could include the monitoring/prediction of water quality which is pumped from the South Fork pump station fed by the proposed Hunter Lake into Lake Springfield. Are sediments and agricultural inputs passed through to Lake Springfield? Further investigation is needed on the state of watershed management practices in Christian and Macoupin counties for much of the Hunter Lake watershed resides in them. There may not be as much organized management within these counties as already established in Sangamon county. Another topic that needs discussed is how much of the acquisition land is being converted to forest and protected habitat?

Holth, N. (2016). Vachel Lindsay Bridge. Historic Bridges.  https://historicbridges.org/bridges/browser/?bridgebrowser=illinois/vachellindsay/ 

CWLP (n.d.). Springfield Water Works.  https://www.cwlp.com/Images/CWLPHistory/CWLP100thPampForWeb.pdf 

CWLP (n.d.). Sangamon Water Works Station.  https://www.cwlp.com/Images/CWLPHistory/WtrHistoryPampForWeb.pdf 

CWLP (n.d.). Lake Springfield Construction.  https://www.cwlp.com/Images/CWLPHistory/Lake75PampForWeb.pdf 

CWLP (n.d.). Three-day Celebration. WMay.  https://www.wmay.com/2021/07/11/july-12-1935-lake-springfield-formally-dedicated/ 

Laswell, C. (1954). Lake Springfield Drought. [Photograph]. Illinois Times.  https://www.illinoistimes.com/springfield/secrets-uncovered-by-1950s-drought/Content?oid=11451798 

Hanson (n.d.). Spaulding Dam.  https://www.hanson-inc.com/portfolio/CWLP-Spaulding-Dam-spillway-gate-rehabilitation/118/portfolio-details 

Sangamon County Soil and Water Conservation District. (n.d.) Sedimentation.  https://www2.illinois.gov/epa/Documents/iepa/water-quality/watershed-management/watershed-based-planning/2018/lake-springfield/lswmp-wbmp.pdf 

Crawford, Murphy, & Tilly Inc. Hunter Lake Map [Map]. City Water, Light, and Power, 2008.

United States Department of Agriculture. 10 Digit Watershed Boundary Dataset [Shapefile].

United States Geological Survey. Landsat 8 [Image]. 2021, November 12

City Water, Light, and Power. (n.d.). Lake and Parks.  https://www.cwlp.com/LakesParksHome/LakesParksHome.aspx 

City Water, Light, and Power. (n.d.). Lake Springfield 1935-2010.  https://www.cwlp.com/Images/CWLPHistory/Lake75PampForWeb.pdf 

Hudson, H. E. & Roberts, W. J. (1955). 1952-1955 Illinois Drought with special reference to Impounding Reservoir Design. Illinois State Water Survey Division.  https://www.isws.illinois.edu/pubdoc/B/ISWSB-43.pdf 

Illinois Council of Best Management Practices. (n.d.). Lake Springfield.  http://illinoiscbmp.com/Watersheds/Lake-Springfield/ 

Knapp, V. H. (1998, April). Operation Alternatives for the Springfield Water Supply System and Impacts on Drought Yield. Illinois State Water Survey Hydrology Division.  https://www.isws.illinois.edu/pubdoc/CR/ISWSCR-626.pdf 

Springfield City Council. (2015, July 21). Hunter Lake.  https://www.springfield.il.us/Docs/Stat%20Sheet%20Aug%202015.pdf 

Stall, J. B., Goffschalk, L. C., & Smith, H. M. (1952). The Silting of Lake Springfield. State Water Survey Division.  https://www.isws.illinois.edu/pubdoc/RI/ISWSRI-16.pdf 

U.S. Army Corps of Engineers. (2021, October 1). Springfield, Illinois (City Water, Light & Power) / Springfield Supplemental Water Supply SEIS – Permits.  https://www.mvr.usace.army.mil/About/Offices/Programs-and-Project-Management/District-Projects/Projects/Article/1172010/springfield-illinois-city-water-light-power-springfield-supplemental-water-supp/