ILLINOIS WATER AND CLIMATE SUMMARY

Transcription

1 ILLINOIS WATER AND CLIMATE SUMMARY March 2013 MARCH 2013 OVERVIEW s and precipitation in Illinois during March were below average. Mean streamflow was above median for the month. Shallow groundwater levels were below long-term average depths. s across Illinois were below normal in March (Figure 1). The statewide monthly average of 34.1 degrees was 7.0 degrees below normal and 21.2 degrees lower than the March 2012 state average. Crop Reporting District (CRD) temperatures ranged from 7.4 degrees below normal (West CRD) to 6.4 degrees below normal (Northeast and East- Central CRD). Precipitation amounts for Illinois in March were below normal (Figure 1). The statewide average of 2.85 inches was 0.15 inches below normal for the state. By CRD, precipitation ranged from 1.62 inches (East- Central CRD) to 5.22 inches (Southwest CRDs). Soil Moisture data will return in the April summary. Mean provisional streamflow aggregated statewide was above the median flow in March, about 125 percent of median (Figure 1). Monthly mean discharge values were primarily in the normal to above normal range for the month. The Illinois, Mississippi, and Ohio Rivers reached local flood stage levels in many areas in mid-march. Water surface levels at the end of March were below full pool/target operating level at five of 25 reporting reservoirs. At the end of the month, Lake Shelbyville was 0.7 feet below the spring target level, Carlyle Lake was 0.1 foot below the spring target level, and Rend Lake was 5.0 feet above the spillway level. The mean level of Lake Michigan remains near its lowest level in the period of record (since 1918). Shallow groundwater levels statewide were below normal with an average departure of -0.8 feet. An increase of 0.2 feet in departures this month was observed from the deviation in normal groundwater levels between February and March (Figure 1). Levels averaged 0.9 feet above February levels and were approximately the same as March of last year. Figure 1 Statewide departures from normal Water and Atmospheric Resources Monitoring Program Contact Jennie R. Atkins: (217) , jatkins@illinois.edu

2 WEATHER/CLIMATE INFORMATION Jim Angel and Jennie Atkins s across the state averaged 34.1 degrees in March, 7.0 degrees below normal. This was a large change from March 2012 when temperatures averaged 55.3 degrees. The warmest temperatures were seen in the state s southern tip where temperature averages ranged between 40 and 45 degrees. The coolest temperatures were in northern Illinois with averages between 25 and 30 degrees. Precipitation for March was 2.85 inches, 0.15 inches below normal (Figure 2). (Precipitation totals include rainfall and the water content of any snow.) Illinois received 9.61 inches of precipitation by the end March 2013, which is 2.41 inches above normal and 4.44 inches greater than what the state had received by the end of March Snowfall for the month ranged from less than 0.5 inches in southern Illinois to more than 12 inches through the central part of the state (Figure 2). This is a large departure from the normal with portions of central Illinois receiving 10 to 12 inches greater than usual. Snowfall totals for winter and early spring (December 1 March 31) ranged from 40 to 50 inches in northwestern Illinois to 7.5 to 10 inches in the southern tip degrees at 8 inches under sod. At the central stations, temperatures averaged 36.8 degrees at 4 inches under bare soil, 37.6 degrees at 4 inches under sod, and 36.7 degrees at 8 inches under sod. In the northern portion of the network, temperatures averaged 33.5 degrees at 4 inches under bare soil, 33.0 degrees at 4 inches under sod, and 32.9 degrees at 8 inches under sod. Precipitation station totals averaged 2.79 inches for March. (The precipitation totals include rainfall and the water content of any snow. Snowfall totals are not recorded separately at the ICN stations.) Precipitation was greater in the south with station totals averaging 4.0 inches for the month. Station totals averaged 2.0 inches at the central stations and 2.2 inches at the northern stations. The highest monthly total was 5.63 inches at Rend Lake (Ina). Hourly and daily weather and soil data for all ICN stations are available on the WARM website at isws.illinois.edu/warm/soiltemp.asp. Soil moisture data will return in the April summary. ILLINOIS CLIMATE NETWORK (ICN) Jennie Atkins The Illinois Climate Network (ICN) consists of 19 stations across the state that collect hourly climate and soil information. Data for March are presented in Table 1. Wind speeds across the network averaged 8.0 mph in March. Station averages ranged from 5.7 mph in Dixon Springs to 12.2 mph in Bondville. The month s highest wind gust of 43.5 mph was measured at the Belleville station on March 5. Air temperatures averaged 34.4 degrees in March, 4.3 degrees higher than February but 8.1 degrees lower than the network s March normal. The highest temperature of the month, 75.2 degrees, was measured at Carbondale on March 15, while the lowest temperature, 2.2 degrees, was recorded at Monmouth on March 3. Soil temperatures rose slightly in March with averages 5 to 9 percent greater than February. However, the soil temperatures were 4 to 5 degrees lower than normal. s at the southern stations averaged 41.5 degrees at 4 inches under bare soil, 41.4 degrees at 4 inches under sod, and Figure 2 Illinois precipitation and precipitation departure from average for March

3 Figure 3 Illinois precipitation and precipitation departure from average for year to date (top), last 6 months (middle), and last 3 months (bottom) 3

4 Monmouth Perry Freeport Big Bend Kilbourne Springfield Belleville Peoria St Charles DeKalb Brownstown Stelle Champaign Bondville Fairfield Olney Table 1. Data from the Illinois Climate Network (ICN), March 2013 Station Ave Wind Speed (mph) Ave Wind Direction ( ) Maximum Wind Gust (mph) Maximum Air Minimum Air Average Air Total Solar Radiation (MJ/m 2 ) Belleville Big Bend Bondville Brownstown Carbondale Champaign DeKalb Dixon Springs Fairfield Freeport Kilbourne Monmouth Olney Peoria Perry (Orr) Rend Lake (Ina) Springfield St. Charles Stelle Rend Lake Carbondale Dixon Springs Table 1 continued Station Average Relative Humidity (%) Total Precipitation (in) Average Dew Point Total Potential Evapotranspiration (in) Ave Soil at 4" under Sod Ave Soil at 8" under Sod Ave Soil at 4" under Bare Soil Belleville Big Bend Bondville Brownstown Carbondale Champaign DeKalb Dixon Springs Fairfield Freeport Kilbourne Monmouth Olney Peoria Perry (Orr) Rend Lake (Ina) Springfield St. Charles Stelle M

5 SURFACE WATER INFORMATION Bill Saylor and Amy Russell 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, the Illinois State Water Survey (ISWS), and the USACE. Provisional discharge data are obtained from the USGS. Table 2 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. Water levels peaked above flood stage in many areas on the Illinois, Mississippi, and Ohio Rivers in mid-march. Provisional monthly mean flows for 26 streamgaging stations located throughout Illinois are shown in Table 3. 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. Long-term mean flows for each month are published by the USGS. The month s median flow for each station listed in Table 3 was determined by ranking the March 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 3 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 3 contribute to their flow.) Mean provisional flow statewide was above the median value for March (about 125 percent of the median) and slightly above the long-term mean for the month (about 105 percent of the mean). Monthly mean streamflow conditions throughout Illinois, as represented by Table 3 stations, were in the normal to above normal range for March, with the exception of the South Fork Sangamon River near Rochester where monthly mean flow remained slightly below normal. Water-Supply Lakes and Major Reservoirs. Table 4 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 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 4), 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-february water levels at 25 reservoirs for which levels were reported last month and this month, reported end-of-march water levels were lower at nine reservoirs, higher at 12 reservoirs, and about the same as at the end of last month at four reservoirs. For the 25 reservoirs with measurements reported at the end of March, water levels were below normal target pool or spillway level at five reservoirs, above target pool levels at 13 reservoirs, and at or above full pool at an additional seven reservoirs. Raccoon Lake level is drawn down to accommodate maintenance of the control gates. Major Reservoirs. Compared to water levels at the end of February, at the end of March, Lake Shelbyville was 0.2 feet lower, Carlyle Lake was 0.9 feet lower, and Rend Lake water level was 1.4 feet higher. At the end of March, Lake Shelbyville was 0.7 feet below the spring target level, Carlyle Lake was 0.1 foot below the spring target level, and Rend Lake was 5.0 feet above the spillway level. (Note that Lake Shelbyville and Carlyle Lake pool levels are actively managed, and that their seasonal target levels increase from March to April.) Great Lakes. Current month mean and endof-month values are provisional and are relative to International Great Lakes Datum The March 2013 mean level for Lake Michigan was feet. The monthly mean level one year ago (March 2012) was feet. The long-term average lake level for March is feet, based on data. In this period of record, the previous lowest mean level for Lake Michigan in March occurred in 1964 at feet, and the highest level for March occurred in 1986 at feet. The month-end level of Lake Michigan was feet. All values are provided by the U.S. Army Corps of Engineers Detroit District. 5

6 Table 2. Peak Stages for Major Rivers during March 2013 River Station River mile* Flood stage (feet)* Peak stage (feet)** Date Illinois 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 (and Addendum, February 2007). **Peak stage based on daily a.m. readings, not instantaneous peak. Stage data obtained from U.S. Army Corps of Engineers. Table 3. Provisional Mean Flows, March 2013 Station Drainage area (sq mi) Years of record 2013 mean flow (cfs) Long-term flows Mean* Median (cfs) (cfs) Flow condition Percent chance of exceedence Days of data this month Rock River at Rockton normal Rock River near Joslin ,700 11, normal Pecatonica River at Freeport normal Green River near Geneseo above normal Edwards River near New Boston above normal Kankakee River at Momence normal Iroquois River near Chebanse normal Fox River at Dayton above normal Vermilion River at Pontiac above normal Spoon River at Seville above normal LaMoine River at Ripley normal Bear Creek near Marceline above normal Mackinaw River near Congerville above normal Salt Creek near Greenview normal Sangamon River at Monticello normal South Fork Sangamon near Rochester below normal Illinois River at Valley City 26, ,820 34,640 30,487 normal Macoupin Creek near Kane normal Vermilion River near Danville normal Kaskaskia River at Vandalia normal Shoal Creek near Breese normal Embarras River at Ste. Marie normal Skillet Fork at Wayne City above normal Little Wabash below Clay City normal Big Muddy at Plumfield above normal Cache River at Forman normal Notes: Source streamflow data are obtained from the U.S. Geological Survey. N/A = not available (due to ice or equipment problems). Much below normal flow = % chance of exceedence. Below normal flow = 70-90% chance of exceedence. Normal flow = 30-70% chance of exceedence. Above normal flow = 10-30% chance of exceedence. Much above normal flow = 0-10% chance of exceedence. *As reported in U.S. Geological Survey (USGS) Water Resources Data, Illinois, Water Year

7 Table 4. Reservoir Levels in Illinois, March 2013 Normal pool Current level Monthly Average difference Years February or target difference from normal change from normal of reported pumpage Reservoir County level (feet) or target (feet) (feet) or target (feet) record (million gallons) Altamont Effingham Bloomington McLean N/A Canton Fulton N/A Carlinville Macoupin Carlyle (1) Clinton N/A Coulterville Randolph N/A N/A N/A Decatur (1,3) Macon Evergreen (4) Woodford N/A Glenn Shoals (2) Montgomery w/hillsboro Greenfield Greene N/A N/A N/A Highland Madison Hillsboro (2) Montgomery Jacksonville (2) Morgan w/mauvaise Terre Kinkaid Jackson Lake of Egypt Williamson N/A Mattoon Coles N/A N/A w/paradise Mauvaise Terre (2) Morgan no meter Mt. Olive (new) Macoupin N/A N/A w/mt. Olive (old) Mt. Olive (old) Macoupin N/A N/A Nashville (3) Washington N/A N/A N/A Pana Christian N/A Paradise Coles N/A N/A Paris (east) Edgar Not PWS Paris (west) Edgar w/paris (east) Pinckneyville Perry N/A N/A N/A Raccoon (1) Marion N/A N/A Rend Franklin N/A Salem (3) Marion Shelbyville (1) Shelby Not PWS Sparta (3) Randolph N/A N/A Spring (3,4) McDonough Springfield (1,3) Sangamon Taylorville Christian Vermilion (4) Vermilion 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 April 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. 7

8 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 of March. Levels were 0.8 feet below normal and ranged from 6.1 feet below to 2.1 feet above normal levels (Table 5). Comparison to Previous Month. For the fourth straight month, shallow groundwater levels were above those of the previous month. Levels averaged 0.9 feet above and ranged from 2.5 feet below to 4.8 feet above levels of February. Comparison to Same Month, Previous Year. Shallow groundwater levels in March were approximately the same as levels measured one year ago. Levels averaged 0.03 feet above this month and ranged from 9.7 feet below to 4.4 feet above levels of March Overall, groundwater conditions are improving, in that this is the first time since January 2012 that the average departure from the previous year has been positive (13 months). Table 5. Month-End Shallow Groundwater Level Data Sites, March 2013 Number Well name County Well depth (feet) 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 Cambridge Henry * NA NA NA NA 5 Fermi Lab DuPage Good Hope McDonough Snicarte Mason Coffman Pike Greenfield Greene Janesville Coles St. Peter Fayette SWS #2 St. Clair Boyleston Wayne Sparta Randolph SE College Saline Bondville Champaign Notes: N/A = Data not available. * Water level fell below the bottom of the well. Averages

9 ADDENDUM Nancy Westcott Imperial Valley. Precipitation for March 2013 was moderate (Figure 5a). Monthly gage totals were largest in the southwestern portion of the network, and smallest in the central and northeastern regions of the network. Individual gage amounts ranged from 3.33 inches at Site #19 to 1.98 inches at Sites #3. The , 30-year average precipitation amounts for March at Havana and Mason City are 2.81 and 2.49 inches, respectively. The March 2013 network average of 2.52 inches is about 114 percent of the 20-year ( ) IVWA March network average of 2.21 inches. Cook County. March 2013 total precipitation was moderate (Figure 5b). Precipitation amounts were greatest in the southwestern region of the network, and least at locations in the southeastern portion of the network. Precipitation values ranged from 2.29 inches at Site #21 (Tinley Park) to 1.57 inches at Site #25 (Chicago Heights). The March 2013 network average of 1.91 inches is about 79 percent of the 23-year ( ) March network average of 2.43 inches. a. Imperial Valley b. Cook County Figure 4 Long-term raingage network precipitation totals (inches) for March 2013 Data sources for information in this publication include the following: CPC - Climate Prediction Center, ISWS - Illinois State Water Survey, MRCC - Midwestern Regional Climate Center, NCDC - National Climatic Data Center, NWS - National Weather Service, USACE - U.S. Army Corps of Engineers, USGS - U.S. Geological Survey, WARM - Water and Atmospheric Resources Monitoring Program, Illinois State Water Survey 2204 Griffith Drive Champaign, IL Tel (217)