Illinois State Water Survey

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1 Illinois State Water Survey Derek Winstanley, Chief 2204 Griffith Dr., Champaign, IL 6120 Tel (217) Fax (217) ILLINOIS WATER AND CLIMATE SUMMARY October 2007 October 2007 Overview (Jim Angel) Temperatures in Illinois during October, the ninth warmest October since 195, were well above average for the third consecutive month. Precipitation was above average. Soil moisture within the top 40 inches of soil was below the long-term statewide average. Mean streamflows were above median heights. Shallow groundwater levels were just below long-term average depths. Temperatures across Illinois (Figure 1) for October were well above average (a +4.-degree departure). Crop Reporting District (CRD) temperatures ranged from 4.0 degrees above average (westsouthwest) to 5. degrees above average (northeast). It was the seventh warmest October in the northeast, east, and east-southeast CRDs, and the tenth warmest in the northwest and southeast CRDs. Precipitation amounts for Illinois in October were above average (Figure 1). The statewide average of 3.52 inches represents a inch departure or 121 percent of average for the month. Precipitation amounts increased from north to south across the state. The northeast CRD received 2.69 inches (97 percent of average), and the southeast CRD recorded 4.0 inches (160 percent of average). Soil moisture in the 0- to 40-inch (0- to -centimeter) layer at the end of October was below normal across large portions of central Illinois, but near to above normal elsewhere (Figure 1). Mean provisional streamflow statewide was above the median flow in October, 149 percent of median (Figure 1). Rivers in Illinois recorded monthly mean discharges in the much below normal to much above normal range. Water surface levels at the end of October were below the normal pool/target operating level at 26 of 29 reporting reservoirs. At the end of October, Rend Lake, Lake Shelbyville, and Carlyle Lake were all below their seasonal target levels. Lake Michigan s mean level remains below the long-term average. Shallow groundwater levels statewide are below normal with an average departure of -0.5 feet (Figure 1). Levels averaged 0.03 feet higher than September levels and were approximately 0.2 feet below October levels last year in O06 N D J07 F M A M J J A S O Note: The WARM Network maps and extended network descriptions appear in the January and July issues. Contact Bob Scott: (217) , rwscott1@uiuc.edu For more information, see Figure 1. Statewide departures from normal

2 Weather/Climate Information (Jim Angel and Bob Scott) Temperatures across Illinois for October were above average (Figure 2 and Table 1). This was the third warmest August October since 195. Extremes ranged from 96 F on October 7 at both Fairfield (Wayne County) and Hidalgo (Jasper County) and on October at Hutsonville (Crawford County) to 26ºF on October 2 at both Congerville (Woodford County) and Decatur (Macon County). Precipitation for October was above average statewide (Figure 2 and Table 1). Cairo (Alexander County) reported the highest one-day precipitation, 5.66 inches on October 1, and also the highest monthly total,.79 inches. Severe weather reported in October included three tornadoes. Western Illinois reported scattered wind damage as severe thunderstorms passed through Missouri, Iowa, and Illinois on October 2. Widespread wind damage was reported throughout central and southern Illinois on October 17. More severe weather occurred throughout eastern and southern Illinois on October 1. Bond and Fayette Counties reported two unconfirmed tornado touchdowns, and another reported in Wabash County near Maud was confirmed. No damage or injuries were reported, however. Illinois Climate Network (ICN) Data. Average daily wind speeds across Illinois for October (Figure 3) ranged from 3.4 mph at Dixon Springs to 13.1 mph at Big Bend. Perry recorded the highest gust (56 mph) on October 1. Numerous other sites exceeded 40 mph that same day. The prevailing wind direction was south-southwesterly in all of Illinois but westerly in far southern Illinois. Wind speeds in excess of mph varied from 50 hours at Dixon Springs to 450 hours at Monmouth. (October has 744 hours.) Average air temperatures ranged from the upper 50s in northern Illinois to 65 F at Fairfield. Solar radiation totals in October continued a strong seasonal decline, varying from 26 Mega-Joules per meter squared (MJ/m 2 ) at Freeport to nearly 350 MJ/m 2 at Belleville and Rend Lake. Potential evapotranspiration observations also declined, varying from a low of 2.2 inches at Freeport to inches at Belleville and Rend Lake. Soil temperatures in Illinois ranged from 55 F at Big Bend to 6 F at Carbondale (4-inch level) and from 61 F at Big Bend to 70 F at Dixon Springs (-inch level). Extended climate outlooks issued by the U.S. Department of Commerce, National Oceanic and Atmospheric Administration, Climate Prediction Center for November and for November January call for a slight chance of above normal temperatures and equal chances of above, below, and normal precipitation across Illinois Figure 2. Illinois temperature and precipitation during October

3 Crop Reporting District Table 1. Illinois Precipitation (inches) and Temperature (ºF) by Crop Reporting District Oct 07 Amount Last Month Last 3 Months Last 6 Months Last 12 Months % Temp Aug 07- % Temp May 07- % Temp Nov 06- % Avg Dev Oct 07 Avg Dev Oct 07 Avg Dev Oct 07 Avg Northwest Northeast West Central East West-southwest East-southeast Southwest Southeast State Average Note: Data are provisional. Complete, quality-controlled data are available about six months after a given month. Temp Dev Soil Moisture Information (Bob Scott) Precipitation in October was above average across Illinois, especially in central and southern areas. Precipitation in late summer across this same region was below average, creating the dry soils now observed in deeper layers (Figure 4). At the end of October, soil moisture in the 0- to 6-inch layer was normal to slightly below normal in west-central Illinois and above normal in southern Illinois. Values ranged from 55 percent of normal at Springfield to more than 160 percent at Olney and Carbondale. Values in the 6- to 20-inch layer were very low at Springfield (less than percent) and above normal in southeastern Illinois, approximately 140 percent at Rend Lake (Ina) and Dixon Springs. Amounts in the 20- to 40-inch layer were less than percent from East Peoria to Springfield, but 12 percent at Belleville and 14 percent at Dixon Springs. Similar amounts in the 40- to 72-inch layer ranged from less than percent at East Peoria and Springfield to more than percent at Monmouth, Stelle, Belleville, Brownstown, and Carbondale. Overall soil moisture in Illinois at the end of October was below normal (Figure 4). Compared to conditions at the end of September, soil moisture at the end of October increased statewide, especially in southern Illinois (Table 2). Values in the 0- to 6-inch layer increased by 1 percent at Belleville, Carbondale, and Rend Lake (Ina), and 126 percent at Olney. Conversely, northern areas reported increases only of about 15 percent. Values in the 6- to 20-inch layer also increased significantly in southern Illinois: nearly 200 percent at Belleville, 150 percent at Brownstown, and percent at Carbondale. Changes were essentially zero in the far north in that layer. Values in the 20- to 40-inch layer generally changed by less than percent, except for an increase of 17 percent at Fairfield. 3

4 A verage W ind S p eed (m p h) A verage W ind D irection (deg) H o u rs W in d S peed A b o ve m ph A verage T em p eratu re (deg F) Total Solar Radiation (MJ/m *m ) Total Potential Evap. (in ) Average 4 Inch Soil Tem perature (deg F ) A verage Inch Soil Tem perature (deg F ) Figure 3. October monthly averages and totals as collected by the Illinois Climate Network 4

5 0-6 inch S oil Layer 6-20 inch S oil Layer inch S oil Layer inch S oil Layer Figure 4. November 1 observed percent-of-normal soil moisture based on mean 5

6 Location Table 2. Soil Moisture in Various Layers on October 27, 2007 Oct (inches) Change from Oct 1 (%) Oct (inches) Change from Oct 1 (%) Oct (inches) Change from Oct 1 (%) Freeport (NW) DeKalb (NE) Monmouth (W) East Peoria (C) Topeka (C) Stelle (E) Champaign (E) Bondville (E) Perry (WSW) Springfield (WSW) Brownstown (ESE) Olney (ESE) Belleville (SW) Carbondale (SW) Ina (SE) Fairfield (SE) Dixon Springs (SE) Surface Water Information (Bill Saylor and Vern Knapp) River and stream discharge and stage data are obtained from gaging stations operated by the U.S. Geological Survey (USGS) or the U.S. Army Corps of Engineers (USACE). The USGS gaging station network is supported, in part, by the Illinois Department of Natural Resources Office of Water Resources and the Illinois State Water Survey (ISWS), and the USACE. Provisional discharge data are obtained from the USGS. Table 3 lists the provisional peak stage for the current month compared to flood stage at selected streamgaging stations located on the Illinois, Mississippi, and Ohio Rivers. The peak stage is determined from the daily morning readings posted by the National Weather Service and/or the USACE. River levels at Table 3 stations did not exceed flood stage in October. Provisional monthly mean flows for 26 streamgaging stations located throughout Illinois are shown (Table 4). Mean values posted by the USGS are listed if available; otherwise, daily mean discharge data posted by the USGS are used to estimate the mean flow for the month. The USGS publishes long-term mean flows for each month. The month s median flow for each station listed in Table 4 was determined by ranking the October mean flow for each year of record, and selecting the middle value, 50 percent exceedence probability. The statewide percent of historical mean flow and percent of historical median flow are calculated by dividing the sum of the average flows this month at stations in Table 4 by the sum of the historical mean and median flows calculated for the month, respectively, at the same stations. This method is intended to weight individual observations proportionately in the aggregate comparison. (The Illinois River and Rock River stations are excluded from the statewide calculation because other rivers listed in Table 4 contribute to their flow.) Mean provisional flow statewide was above the median value for October (149 percent of the median) and below the long-term mean for the month (69 percent of the mean). Mean streamflow conditions in Illinois in October ranged from much below to much above normal. Water-Supply Lakes and Major Reservoirs. Table 5 lists reservoirs in Illinois, their normal pool or target water surface elevation, and other data related to observed variations in water surface elevations. Reservoir levels are obtained from a network of cooperating reservoir operators who are contacted each month by ISWS staff for the current water levels. Reservoir levels are reported in terms of their difference from normal pool (or target level). The 6

7 River Station River Illinois mile* Table 3. Peak Stages for Major Rivers during October 2007 Flood stage (feet)* Peak stage (feet)** Date Morris La Salle Peoria Havana Beardstown Hardin Mississippi Dubuque Keokuk Quincy Grafton St. Louis Chester Thebes Ohio Cairo Notes: *River mile and flood stage from River Stages in Illinois: Flood and Damage Data, Illinois Department of Natural Resources, Office of Water Resources, August 2004 (except as revised by the National Weather Service). **Peak stage based on daily a.m. readings, not instantaneous peak. average of the month-end readings for the period of record is reported in terms of the difference from normal pool or target level (column 6 of Table 5), and the number of years of record for each reservoir also is given (column 7). Most reservoirs serve as public water supplies, with the exceptions noted in the last column. Compared to end-of-september water levels at 2 reservoirs, end-of-october water levels had decreased at 16 reservoirs, had increased at 9 reservoirs, and were the same as last month at 3 reservoirs. For the 29 reservoirs with observations reported at the end of October, 26 reservoirs were below normal pool (or target operating level), two reservoirs were above normal pool, and one reservoir was at normal pool or spillway (Sparta Reservoir, which continues to be supplemented with water withdrawn from the Kaskaskia River). Salem Lake was supplemented with water withdrawn from Carlyle Lake. By the end of October, the City of Centralia was withdrawing from Carlyle Lake due to the low water surface level of Raccoon Lake. Virginia Lake (no longer a community water supply) was drained for maintenance. Major Reservoirs. Compared to end-of-september water levels, end-of-october water levels were 0.1 foot lower at Rend Lake, 0.2 foot lower at Carlyle Lake, and 0.3 foot higher at Lake Shelbyville. At the end of October, the water surface level at Rend Lake was 1.2 feet below the spillway, Carlyle Lake was a foot below its seasonal target level, and Lake Shelbyville was 1.3 feet below its seasonal target level. According to USACE records, Rend Lake was at its second lowest end-of-october level since 1974 (only 0.1 foot above the October 197 month-end level). Great Lakes. Current month mean and end-of-month values are provisional and are relative to International Great Lakes Datum 195. The October mean level for Lake Michigan was feet, compared to a mean level of feet in October The long-term average lake level for October is 57.9 feet, based on data. Historically, the lowest mean level for Lake Michigan in October occurred in 19 at feet, and the highest level occurred in 196 at 52.3 feet. The month-end level of Lake Michigan was feet. The October 2007 mean level for Lake Michigan was its second lowest mean level for the month of October since 19 (only 0.03 foot above the October 2003 mean level). 7

8 Table 4. Provisional Mean Flows, October 2007 Drainage Years 2007 Long-term flows Percent Days of area of mean flow Mean* Median chance of data this Station (sq mi) record (cfs) (cfs) (cfs) Flow condition exceedence month Rock River at Rockton above normal Rock River near Joslin above normal 1 31 Pecatonica River at Freeport much above normal 31 Green River near Geneseo normal Edwards River near New Boston normal Kankakee River at Momence above normal Iroquois River near Chebanse normal Fox River at Dayton above normal Vermilion River at Pontiac above normal Spoon River at Seville below normal 2 31 LaMoine River at Ripley much below normal Bear Creek near Marceline below normal 1 31 Mackinaw River near Congerville normal Salt Creek near Greenview below normal Sangamon River at Monticello below normal 7 31 South Fork Sangamon near Rochester much below normal Illinois River at Valley City 26,743 6,470 12,420 7 normal Macoupin Creek near Kane below normal 4 31 Vermilion River near Danville normal Kaskaskia River at Vandalia much below normal Shoal Creek near Breese below normal Embarras River at Ste. Marie normal Skillet Fork at Wayne City normal Little Wabash below Clay City normal Big Muddy at Plumfield normal Cache River at Forman much above normal 9 31 Notes: N/A = not available. Much below normal flow = 90-% chance of exceedence. Below normal flow = 70-90% chance of exceedence. Normal flow = 30-70% chance of exceedence. Above normal flow = -30% chance of exceedence. Much above normal flow = 0-% chance of exceedence. *As reported in U.S. Geological Survey (USGS) Water Resources Data, Illinois, Water Year 2006.

9 Table 5. Reservoir Levels in Illinois, October 2007 Current level Average September Normal pool difference from Monthly difference from Years reported or target normal or target change normal or target of pumpage Reservoir County level (feet) (feet) (feet) (feet) record (million gallons) Altamont Effingham 5 N/A N/A Bloomington McLean N/A Canton Fulton Carlinville Macoupin Carlyle (1) Clinton N/A Coulterville Randolph N/A N/A N/A Crab Orchard Williamson N/A N/A Not PWS Decatur (1,3) Macon ,154.0 Devils Kitchen Williamson 5.0 N/A N/A -0. Not PWS Evergreen (4) Woodford N/A Glenn Shoals Montgomery w/hillsboro Greenfield Greene Highland Madison Hillsboro Montgomery Jacksonville (2) Morgan 4.0 N/A N/A w/mauvaise Terre Kinkaid Jackson Lake of Egypt Williamson N/A N/A N/A Little Grassy Williamson N/A N/A Not PWS Mattoon Coles w/paradise Mauvaise Terre (2) Morgan 5.5 N/A N/A no meter Mt. Olive (new) Macoupin N/A N/A w/mt. Olive (old) Mt. Olive (old) Macoupin Nashville (3) Washington Pana Christian N/A Paradise Coles Paris (east) Edgar Paris (west) Edgar w/paris (east) Pinckneyville Perry N/A N/A Pittsfield Pike Raccoon (1) Marion N/A N/A Rend Franklin N/A Salem (3) Marion Shelbyville (1) Shelby Not PWS Sparta (3) Randolph Spring (4) McDonough Springfield (1,3) Sangamon Taylorville Christian Vermilion (4) Vermilion Virginia Cass 5.0 N/A N/A Not PWS Notes: Normal pool and target level datum is NGVD Current levels reported represent water surface levels at the end of the month, not the monthly average. Average difference from normal or target level is the arithmetic average of reported month-end values for the period of record indicated. Years of record = total number of monthly readings included in month-end average. Total period of record may be longer. Not PWS = not a public water supply. N/A = not available. (1) Target operating level may vary. Seasonal target levels this month represent November 1 values. (2) Instrumentation not available to measure height of water elevation above spillway. (3) Natural inflow can be supplemented by other sources. (4) Normal pool elevations have changed during period of record reported. 9

10 Groundwater Information (Ken Hlinka) Comparison to Average Levels. Shallow groundwater levels in 15 observation wells, which are remote from pumping centers, were below average for the month. October levels were 0.5 foot below normal and ranged from 3.1 feet below to 2.4 feet above normal levels (Table 6). Water levels at Snicarte (Mason County) were below the bottom of the well for the third consecutive month. Comparison to Previous Month. Shallow groundwater levels were above those of September. Levels averaged 0.03 foot higher and ranged from feet below to 4. feet above levels last month. Comparison to Same Month, Previous Year. Shallow groundwater levels in October were below levels measured one year ago. Levels averaged 0.2 feet below and ranged from 4.9 feet below to 7.4 feet higher than during October Table 6. Month-End Shallow Groundwater-Level-Data Sites, October 2007 Number Well name County Well depth (feet) This month s reading (depth to water, feet) 15-year avg. level (feet) Deviation from Period of Previous record avg. month (feet) (feet) Previous year (feet) 1 Galena JoDaviess Mt. Morris Ogle Crystal Lake McHenry Cambridge Henry * N/A N/A N/A N/A 5 Fermi Lab DuPage Good Hope McDonough Snicarte Mason * N/A N/A N/A N/A Coffman Pike Greenfield Greene Janesville Cumberland St. Peter Fayette SWS #2 St. Clair Boyleston Wayne Sparta Randolph SE College Saline Dixon Springs Pope Bondville Champaign Notes: N/A = Data not available. *Data not used in analysis. Averages Addendum (Nancy Westcott) Imperial Valley Precipitation. October 2007 precipitation amounts (Figure 5a) were moderate. Monthly gage totals were greatest in the eastern portion of the network, and precipitation was lightest in the central and northern regions of the network. Individual gage amounts ranged from 3.31 inches at site #7 to 1.39 inches at site #2. The 30-year, , average precipitation amounts for October at Havana and Mason City are 2.6 and 2.73 inches, respectively. The October 2007 network average of 2.30 inches was about 95 percent of the 15-year ( ) October network average of 2.42 inches. Cook County Precipitation. October 2007 precipitation amounts (Figure 5b) were below average. The greatest precipitation was in the south-central portion of the network, and the lightest precipitation was in the western region of the network. Precipitation values ranged from inches at site #13 (near th Street) to 1.25 inches at site #19 (Avenue O, near Wolf Lake). The October 2007 network average of 1.9 inches was about 61 percent of the 1-year ( ) October network average of 3.11 inches.

11 a. Imperial Valley b. Cook County October 2007 Figure 5. Long-term raingage network precipitation totals (inches) for October 2007 Data sources for information in this publication include the following: CPC - Climate Predication Center, ISWS - Illinois State Water Survey, MRCC - Midwestern Regional Climate Center, NCDC - National Climate Data Center, NWS - National Weather Service, USACE - U.S. Army Corp of Engineers, USGS - U.S. Geological Survey, WARM - Water and Atmospheric Resources Monitoring Program, Equal opportunity to participate in programs of the Illinois Department of Natural Resources (IDNR) and those funded by the U.S. Fish and Wildlife Service and other agencies is available to all individuals regardless of race, sex, national origin, disability, age, religion, or other non-merit factors. If you believe you have been discriminated against, contact the funding source s civil rights office and/or the Equal Employment Opportunity Officer, IDNR, One Natural Resources Way, Springfield, IL ; 217/ ; TTY 217/