Table 1. Illinois Precipitation (inches) and Temperature (BF) by Crop Reporting District

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1 ILLINOIS DEPARTMENT OF NATURAL RESOURCES Illinois State Water Survey Derek Winstanley, Chief 04 Griffith Dr., Champaign, IL 610 Tel (1) Fax (1) ILLINOIS WATER AND CLIMATE SUMMARY February 000 February 000 Overview (Bob Scott) Temperatures across Illinois in February were well above average and precipitation was above average Soil moisture within the top inches of soil was just below the long-term statewide average for the month Mean streamflows were below median values Shallow groundwater levels were just below the long-term average Better than average precipitation across most of Illinois began a reversal of the decreasing trends in the state's water resources Some areas in central and southsouthwestern Illinois still exhibit a notable moisture deficit as indicated by soil moisture, streamflows, and ground-water levels Temperatures across Illinois (Figure 1) for February were well above average (a + -degree departure) By crop reporting districts, temperatures ranged from 6 degrees above average (northwest, east, and southeast) to 3 degrees above average (west) Precipitation amounts (Figure 1) were above the long-term average value for the month The statewide average of 69 inches represents a inch departure or 1 percent of average District precipitation totals were above average, ranging from 1 49 inches (northeast) to 5 3 inches (southeast), while percent of average precipitation values ranged from 10 percent (west-southwest) to 196 percent (southeast) Soil moisture conditions at the end of February were just below normal across Illinois in near surface layers, but considerable dryness continued over central and southwestern Illinois in the two lowest layers Mean provisional streamflow statewide was below the median flow, 54 percent of median (Figure 1) Stations in northern Illinois recorded mean flows in the normal range Reporting stations in central and southern Illinois continued to record flows in the below normal to much below normal range Peak stages on the Illinois River did not exceed flood stage Mississippi River stations along the Illinois border and the Ohio River at Cairo also recorded peak stages well below flood stage Water surface levels at the end of February were below the normal pool at 6 of the 3 reservoirs reporting Water surface levels at Carlyle Lake and Lake Shelbyville were just the above target operating level Rend Lake was 0 9 feet below the target operating level Lake Michigan's mean level remains below the long-term average Statewide, shallow ground-water levels, although below average for February by 0 6 feet, are recovering from dry conditions Levels averaged about 3 feet above those of last month and were approximately feet below February levels one year ago Note: The WARM Network maps and extended network descriptions appear in the January and July issues Figure 1 Statewide departures from normal Contact Bob Scott: (1) , r-scott5@uiuc.edu On the Web at 1

2 Weather/Climate Information (Nancy Westcott, Jim Angel, and Bob Scott) Cook County Precipitation January precipitation (Figure ) amounts were small and relatively uniform Site values for the month ranged from 1 63 inches at site #4 (Skokie) to 0 9 inches at site # (east of Chicago Heights) Slightly heavier precipitation occurred in the northeastern and west-central area of the network, and the lightest precipitation occurred in the southeastern portion of the network The January 000 network average of 1 33 inches was about 54 percent of the ten-year ( ) January network average of 44 inches Temperatures across Illinois for February were much warmer than average statewide (Figure 3 and Table 1) with the west district reporting the warmest departure This was the ninth warmest February in Illinois since 195 Record warm weather occurred throughout Illinois on February Some of the records established for the day were: 0 F (Waterloo), 9 F (Belleville), 3 F (Ottawa), F (Springfield, Champaign a new record high for the month and Decatur), and 1 F (Moline) The coolest reading for the month was - F on February (Mount Carroll and St Charles) and on February 9 (Rochelle) The warmest reading was 1 F on February 4 (Belleville) Precipitation across Illinois for February was above average (Figure 3 and Table 1) This was the 16th wettest February in Illinois since 195 All districts reported above average precipitation; however, heavier amounts fell in the southern third of the state The largest monthly total N 15 Scale of Miles Lake Michigan Figure Cook County precipitation (inches) during January was 6 11 inches reported at Smithland Lock and Dam Snowfall was generally light across the state except for the northwest and northeast districts The largest monthly snowfall was 14 5 inches reported at Rochelle, followed closely by 13 inches at Moline On February 9, a strong low-pressure system moving through the Midwest triggered thunderstorms in Illinois, some of which were severe High winds overturned a tractor-trailer truck near Warsaw (Hancock County) and 1.0 ILLINOIS INDIANA Temperature Difference from Average ( o F) " 6 Precipitation (inches) Figure 3 Illinois precipitation and temperatures during February 000

3 Table 1. Illinois Precipitation (inches) and Temperature (BF) by Crop Reporting District Crop Reporting District Feb 00 Amount Last Month Last 3 Months Last 6 Months Last 1 months % Temp Dec 99- % Temp Sep 99- % Temp Mar 99- % Avg Dev Feb 00 Avg Dev Feb 00 Avg Dev Feb 00 Avg Temp Dev Northwest Northeast West Central East West-southwest East-southeast Southwest Southeast State Average Note: Data are provisional. Complete, quality controlled data are available about three months after a given month. downed large tree limbs and power lines near Avon (Fulton County); a wind gust of 51 mph was reported at Lincoln (Logan County); and one-inch hail was reported at Rushville (Schuyler County) Illinois Climate Network (ICN) Data Average daily wind speeds across Illinois for February (Figure 4) ranged from 5 mph at Dixon Springs to 1 mph at Stelle The highest wind gust for the month occurred at Stelle, 56 mph on February 6 The prevailing wind direction for the month was from the south southwest to southwest statewide Wind speeds in excess of mph varied considerably from 156 hours at Dixon Springs to 546 hours at Stelle (February has 696 hours) Average temperatures across the state ranged from 3 F at St Charles to the middle s across southern Illinois Solar radiation was fairly similar everywhere, ranging from 9 Mega-Joules per meter squared (MJ/ m ) at Springfield to 305 MJ/m at Dixon Springs and DeKalb on opposite ends of the state Potential evapotranspiration also was quite constant and varied from just under 1 6 inches across northern Illinois to 1 inches at Fairfield in southern Illinois Soil temperatures at the 4- and -inch levels ranged from F across northern Illinois to near F in the far south Extended climate outlooks issued by the U S Department of Commerce, National Atmospheric and Oceanic Administration, Climate Prediction Center for March call for a slight to moderate chance of above normal temperatures over southern Illinois and equal chances of above, below, and normal precipitation over all of Illinois The outlooks for climatological spring, March May, call for a slight chance of above normal temperatures and precipitation over southern Illinois Elsewhere equal chances exist for above, below, and normal temperature and precipitation Soil Moisture Information (Bob Scott) Above average levels of precipitation occurred across southern Illinois while near average rainfall was prevalent in much of the central and northern parts of the state Soil moisture conditions at the end of February (Figure 5) were near normal in both the 0- to 6- and 6- to 0-inch layers across all of Illinois Values were between and percent of normal nearly everywhere in both layers, exceeding average soil moisture only in southeastern Illinois Conditions at 0 to and to inches of depth, however, showed high spatial variability and were much below normal in central and southwestern Illinois Large areas of above normal soil moisture appeared for the first time in several months around the western, northern, and eastern borders of Illinois Amounts less than percent of normal were once again observed in the driest regions, however Overall, throughout the first inches of depth, statewide soil moisture at the end of February averaged just below the mean for the month (Figure 1) Compared to one month ago, soil moisture during February (Table ) generally increased in all layers over all of Illinois Most increases were substantial, from 10 to percent Several sites reported increases greater than 35 percent Surface Water Information (Sally McConkey) 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 (USACOE) The USGS gaging station network is supported in part by the Illinois Department of Natural Resources Office of Water Resources and Illinois State Water Survey, and USACOE Provisional discharge data are obtained from direct computer access to USGS Peak stage data are 3

4 Average Wind Speed (mph) 6 Average Wind Direction (deg) Total Hours Wind 3 Speed Above mph Average Temperature (deg F) Total Solar Radiation (MJ/m*m).0 Total Potential Evapotranspiration (in).0 Average 4 Inch (10 cm) Soil Temperature (deg F) Average Inch (0 cm) Soil Temperature (deg F) Figure 4 February monthly averages and totals as collected by the Illinois Climate Network

5 < > 0-6 inch Soil Layer 6-0 inch Soil Layer inch Soil Layer - inch Soil Layer Figure 5 March 1 observed percent-of-normal soil moisture based on mean 5

6 Table. Soil Moisture in Various Layers on March 1, 000 Location Mar (inches) Change from Feb 1 (%) Mar (inches) Change from Feb 1 (%) Mar (inches) Change from Feb 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) obtained from readings posted on the Internet by USGS and USACOE Values reported do not reflect final or official discharges and stages Table 3 lists streamgaging stations located on the Illinois, Mississippi, and Ohio Rivers, flood stage, and the provisional peak stage for the current month Along the Illinois River, peak stages did not exceed flood stage, and peak stage occurred during the last few days of the month The Mississippi River peaked below flood stage at stations along the Illinois border, as did the Ohio River at Cairo Peak flow at these stations was mostly recorded on February 9 Table 4 lists 1 streamgaging stations located throughout Illinois Provisional monthly mean flows posted by USGS are listed if available; otherwise, daily mean discharge data posted by USGS were used to estimate the mean flow for the month Long-term mean flows for each month are published by USGS The month's median flow for each station listed in Table 4 was determined by ranking the February mean flow for each year of record and selecting the middle value ( percent exceedence probability) Mean flows for February at all but one station listed in Table 4 exceeded those recorded in January Mean flows in the northern third of Illinois were within the normal range Mean flows in central and southern Illinois were in the below normal to much below normal range for February Because the Shoal Creek gaging station near Breese (35- square-mile drainage area) has been experiencing problems, discharge at this station (see Table 4) was estimated from the flow recorded for Shoal Creek near Pierron (6-square-mile drainage area) The mean provisional flow statewide was below the median this month (54 percent of median) and below the mean (46 percent of mean) Water-Supply Lakes and Major Reservoirs Table 5 lists reservoirs in Illinois and their month-end water surface elevation, normal pool, and other data related to observed variations in water surface elevations Water withdrawals from public water-supply reservoirs are reported for the previous month as available Most reservoirs listed in Table 5 serve as public water supplies, with the exceptions noted in the last column Compared to levels at the end of January at reservoirs, the water surface elevation at the end of February had risen at 4 reservoirs and had decreased at 4 reservoirs The reported elevation was the same as last month at eight reservoirs Of the 3 reservoirs reporting this month, reservoirs had water surface levels above the target operating level, 4 reservoirs were at normal pool, and 6 reservoirs were below normal pool at the end of February Five of the seven reservoirs that were above normal or target pool elevation are not used for public water supply Two reservoirs, Mauvaise Terre and Paris West, have remained at normal pool for the past four months These reservoirs have natural inflows augmented by pumpage from a second, conjunctive use reservoir The water level at Decatur's reservoir and at Lake Vermilion serving Danville rose more than 3 feet since the end of January However, reservoirs serving Altamont, Bloomington, Canton, Carlinville, Evergreen, Pana, Paris, and Springfield were 3 feet or 6

7 Table 3. Peak Stages for Major Rivers, February 000 River Station River mile* Illinois Mississippi Ohio Flood stage (feet)* Peak stage (feet)** Date Morris La Salle Peoria Havana Beardstown Meredosia Hardin Dubuque Keokuk Quincy Grafton St. Louis Chester Thebes 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, July 199. **Peak stage based on daily a.m. readings, not instantaneous peak. Table 4. Provisional Mean Flows, February 000 Drainage Years 000 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 6,3 64 3,5 3,91 3,31 normal 44 9 Rock River near Joslin 9, ,04 6,46 5,51 normal 5 9 Pecatonica River at Freeport 1, , normal 53 9 Green River near Geneseo 1, normal 5 Edwards River near New Boston normal 43 Kankakee River at Momence,94 1 1,1,,490 normal 63 9 Fox River at Dayton,6 0 1,699,0 1,635 normal 9 Vermilion River at Pontiac much below normal 95 9 Spoon River at Seville 1, ,411 1,6 below normal 0 9 LaMoine River at Ripley 1, ,030 4 below normal 9 Mackinaw River near Congerville much below normal 96 9 Sangamon River at Monticello below normal 3 9 Vermilion River near Danville 1, ,41 1,031 below normal 4 9 Kaskaskia River at Vandalia 1,9 9 0,65 1,4 much below normal 9 9 Shoal Creek near Breese ** much below normal 96 9 Embarras River at Ste. Marie 1, ,904 1, below normal Skillet Fork at Wayne City normal 6 9 Big Muddy at Plumfield , below normal 9 Notes: *As reported in U.S. Geological Survey (USGS) Water Resources Data, Illinois, Water Year 199. * *Estimated. Much below normal flow = 90-% chance of exceedence. Below normal flow = 0-90% chance of exceedence. Normal flow = 30-0% chance of exceedence. Above normal flow = 10-30% chance of exceedence. Much above normal flow = 0-10% chance of exceedence.

8 Table 5. Reservoir Levels in Illinois For security considerations, statewide tabular reservoir data are not available on the Internet. Specific data requests may be made to Sally McConkey at:

9 more below normal pool (spillway elevation) Seventeen of the 3 reservoirs reporting this month were a foot or more below normal pool Month-end average levels and current month-end levels were available for 3 reservoirs this month, of which 4 reservoirs ended February with water levels below their average month-end level for February Major Reservoirs Water levels at Carlyle Lake, Lake Shelbyville, and Rend Lake have increased since the end of January At the end of February, water surface levels at Carlyle Lake and Lake Shelbyville were 0 1 feet above target operating levels The water surface level was 0 9 feet below the target level at Rend Lake Great Lakes Current month mean and end-of-month values are provisional and are relative to International Great Lakes Datum 195 The February mean level for Lake Michigan was feet, compared to a mean level of 5 feet in 1999 The long-term average lake level for February is 5 54 feet, based on data Historically, the lowest mean level for Lake Michigan in February occurred in 1964 at 56 0 feet, and the highest level occurred in 196 at 51 0 feet The month-end level of Lake Michigan was 5 06 feet Ground-Water Information (Ken Hlinka) Comparison to Average Levels Shallow ground-water levels in 14 observation wells that are remote from pumping centers were below average levels for February (Table 6) Levels averaged 0 6 feet below and ranged from 5 feet below to 5 3 feet above average One well, SE College (Saline County), is currently at a record low groundwater level for February The largest deviations from normal occurred in the west-southwest crop reporting district along the western edge of Illinois Increased precipitation throughout the state is reflected in a large increase in average water levels from January to February Dramatic increases are not uncommon in large-diameter bored wells in response to precipitation recharge These wells typically tap thin lenses of water-bearing silt, sand, or gravel only a few inches thick and very near the surface The proximity of these lenses to the surface, the connection of the lenses to the bored well casing, and the duration of the rainfall event all have an impact on the movement of shallow ground water into these types of wells This month's readings reflect this quick precipitation recharge into the network wells Comparison to Previous Month Shallow ground-water levels from all areas except the central crop reporting district during February were above those of last month Levels averaged 3 feet higher and ranged from 0 1 feet below to feet above levels in January Comparison to Same Month, Previous Year Shallow ground-water levels throughout most of Illinois were below levels of February 1999 during February 000 Levels averaged feet lower and ranged from 10 4 feet below to 1 feet above the levels of last year Table 6. Month-End Shallow Ground-Water Level Data Sites, February 000 Number Well name County This month s reading (depth to water, feet) 15-year avg. level (feet) Deviation from Period of record avg. (feet) Previous month (feet) Previous year (feet) 1 Galena JoDaviess Mt. Morris Ogle Crystal Lake McHenry NA NA NA NA NA 4 Cambridge Henry Fermi Lab DuPage NA 6 Good Hope McDonough NA NA NA NA NA Snicarte Mason Coffman Pike Greenfield Greene Janesville Cumberland St. Peter Fayette SWS # St. Clair NA NA NA NA NA 13 Boyleston Wayne Sparta Randolph SE College Saline Dixon Springs Pope Bondville Champaign