ILLINOIS WATER AND
CLIMATE SUMMARY
MARCH 2017 OVERVIEW
March 2017
4(411(:65+1-4
Temperatures and precipitation in March were above the long-term
average in Illinois. Mean streamflow statewide was below the median for
the month. Shallow groundwater levels were slightly above the long-term
average depths.
Air temperatures averaged 43.2 degrees in March, 1.9 degrees above
the long-term average (Figure 1). The northeast crop reporting district
(CRD) had the lowest average monthly temperature with 38.3 degrees.
The highest average was 48.2 degrees, reported from both the southwest
and southeast districts.
Precipitation averaged 3.53 inches, 0.57 inches above the longterm average. The east-southeast CRD was the driest with an average
of 2.70 inches. The wettest was the northeast district with an average of
4.46 inches for the month.
Soil moisture was high for most of March, rising an average of
3 percent over the month at 2-inch depths. At the end of March, statewide
levels averaged 0.41 water fraction by volume (wfv) at 2 inches, 0.40 wfv
at 4 inches, 0.39 wfv at 8 inches, and 0.41 wfv at 20 inches. Moisture
levels were at or near field capacity at most monitoring locations.
Mean provisional streamflow aggregated statewide was below
the long-term median flow for March, about 60 percent of the median
(Figure 1). Monthly mean discharge values were in the much below normal
to normal range for March.
Water surface levels at the end of March were below the full pool/
seasonal target level at 7 of 27 reporting reservoirs. At the end of March,
Rend Lake was 1.7 feet above the spillway level, Carlyle Lake was 0.4 feet
above the April 1 target level, and Lake Shelbyville was 1.7 feet below the
April 1 target level.
Lake Michigan’s level was above its long-term mean for the month.
Shallow groundwater levels were just above normal this month
with an average departure of 0.1 foot (Figure 1). An increase of 0.5 feet in
departure was observed from the deviation in normal groundwater levels
between February and March. Levels averaged 1.1 feet above February
levels and were 1.0 foot below March levels of last year.
Figure 1
Statewide departures from normal
Water and Atmospheric Resources Monitoring Program | www.isws.illinois.edu/warm
Contact Jennie R. Atkins: (217) 333-4966, email: [email protected]
WEATHER/CLIMATE INFORMATION
and Cook counties reported more than 7 inches for the
month. A station in Homer Glen in Will County reported
the month’s highest total of 8.86 inches.
Conditions were drier in east-central Illinois where
stations reported less than 2 inches of rain.
Snow fell across the state in March. The heaviest
totals were in northeastern Illinois, which was affected
by lake-effect snowfalls. A Waukegan station in Lake
County reported 16.4 inches, the highest for the month.
Severe weather reports in Illinois included 6 reports
of tornadoes, 20 of hail, and 68 of wind, according to
the NOAA Storm Prediction Center. (Multiple reports
may describe the same event.)
Drought conditions in Illinois, as described by
the March 28 U.S. Drought Monitor report, included
37 percent of the state listed as abnormally dry and
17 percent as in moderate drought. The affected areas
included all of southern Illinois and most of the western
part of the state.
—Jim Angel and Jennie Atkins
The following description of precipitation,
temperature, and snowfall (in winter) comes from
data compiled by networks that report to the National
Oceanic and Atmospheric Administration (NOAA). There
are over 650 reporting sites in Illinois alone. These data
are provisional and may change slightly over time.
Temperatures in March were near normal with
a monthly average of 43.2 degrees or 1.9 degrees
above the long-term average. Temperatures reached
into the 80s for several stations with lows falling into
the single digits. The month’s highest temperature
was 86 degrees, recorded at the Belleville research
station in St Clair County. Two stations, Altona in Knox
County and Illinois City Dam 16 in Rock Island County,
reported minimum temperatures of 6 degrees, the
lowest of the month.
Precipitation averaged 3.53 inches for the
month, 0.57 inches above the long-term average. The
northeast received the most rain as stations in Will
Table 1. Temperature and Precipitation for March 2017
Temperature
(°F)
Departure
from long-term average
(1981 – 2010)
Precipitation
(in)
Illinois
43.2
+ 1.9
3.53
CRD 1 (northwest)
38.8
+ 1.2
3.60
CRD 2 (northeast)
38.3
+ 0.7
4.46
CRD 3 (west)
42.9
+ 2.3
3.37
CRD 4 (central)
42.2
+ 1.9
3.58
CRD 5 (east)
41.7
+ 1.9
3.35
CRD 6 (west southwest)
45.7
+ 2.7
3.56
CRD 7 (east southeast)
44.9
+ 1.9
2.70
CRD 8 (southwest)
48.2
+ 2.3
3.48
CRD 9 (southeast)
48.2
+ 2.4
3.77
_______________
Notes:
Data from NOAA’s National Centers for Environmental Information, accessed 4/6/2017.
2
Departure
from long-term average
(1981 – 2010)
+ 0.57
+ 1.16
+ 2.10
+ 0.69
+ 0.90
+ 0.69
+ 0.64
- 0.57
- 0.35
- 0.39
Figure 2
Illinois precipitation, temperature, and their departures from average, as well as snowfall, for March 2017
Source: cli-MATE, Midwestern Regional Climate Center. http://mrcc.illinois.edu/CLIMATE accessed on: April 3, 2017
3
Figure 3
Illinois precipitation and precipitation departure from average for year to date (top), last 6 months (bottom)
Source: cli-MATE, Midwestern Regional Climate Center. http://mrcc.illinois.edu/CLIMATE accessed on: April 3, 2017
4
Figure 4
U.S. Drought Monitor report for Illinois
Source: U.S. Drought Monitor. http://droughtmonitor.unl.edu accessed on: March 30, 2017
ILLINOIS CLIMATE NETWORK (ICN)
Under sod, temperatures from 32.9 to 65.0 degrees
at depths of 4 inches and 34.9 to 62.3 degrees at
8 inches were reported.
Precipitation increased 2.28 inches from February
to a network average of 3.28 inches, or 0.60 above the
long-term average. The highest total, 4.77 inches, was
recorded at the Springfield station. The lowest was
2.26 inches, recorded at Fairfield. Fourteen out of the
19 stations had monthly totals greater than their longterm average.
Soil moisture remained high through March for
most of the state. Soil moisture levels at 2-inch depths
rose 3 percent, on average, over the month to a
network average of 0.41 water fraction by volume (wfv)
on March 31. Similar patterns were seen at 4, 8, and
20 inches, ending the month with averages of 0.40,
0.39, and 0.41 wfv, respectively.
The lowest levels were observed in west-central
Illinois where soil moisture declined for most of the
first three weeks of March. Rains over the last week
caused soil moisture to increase, rising an average
of 29 percent from March 24 to March 31 at 2-inch
depths.
Soil moisture levels at 39 and 59 inches were steady
for most of March with end-of-the-month averages of
0.44 and 0.42 wfv, respectively.
—Jennie Atkins
The Illinois Climate Network (ICN) consists of 19
stations across the state that collect hourly weather
and soil information. ICN data for March are presented
in Table 2.
Wind speeds averaged 9.0 mph in March, 0.9 mph
higher than in February and 0.5 mph higher than the
long-term average. Bondville had the highest station
average for the month with 13.7 mph. The highest
reported wind gust was 61.7 mph, measured at the
Snicarte station on March 6.
Air temperatures rose 1.5 degrees from February
to an average of 44.1 degrees. Temperatures were
1.6 degrees above the network’s long-term average.
Monthly station highs ranged from the mid-70s to the
mid-80s throughout Illinois as the monthly lows fell
into the teens. March’s highest temperature was 85.3
degrees, measured at the Belleville station on March
20. The Big Bend station had the month’s lowest
temperature, 9.2 degrees, reported on March 15.
Soil temperatures rose slightly in March to
monthly averages in the mid-40s at all depths.
Temperatures averaged 3 to 4 degrees above February
and 2 to 3 degrees above the long-term average.
Under bare soil, temperatures ranged from 26.3 to
71.7 at depths of 2 inches and 29.7 to 74.0 at 4 inches.
5
Table 2. Data from the Illinois Climate Network (ICN), March 2017
Station
Ave Wind
Speed
(mph)
Belleville
Big Bend
Bondville
Brownstown
Carbondale
Champaign
DeKalb
Dixon Springs
Fairfield
Freeport
Monmouth
Olney
Peoria
Perry
Rend Lake
Snicarte
Springfield
St. Charles
Stelle
9.2
10.0
13.7
8.1
8.2
6.6
11.4
5.4
8.5
6.7
12.4
7.2
9.2
8.0
6.4
11.3
7.6
8.5
12.4
Ave Wind
Direction
(°)
Maximum
Wind Gust
(mph)
182.2
175.2
177.0
171.0
200.3
178.3
170.4
184.1
177.7
175.1
175.3
173.8
179.3
186.4
181.6
181.9
185.1
169.6
177.5
Maximum Air
Temperature
(°F)
54.0
44.6
54.6
53.7
41.6
39.2
50.2
38.6
44.1
49.3
54.9
39.3
61.5
47.0
35.7
61.7
34.8
49.9
50.8
Minimum Air Average Air
Temperature Temperature
(°F)
(°F)
85.3
82.9
77.3
78.4
77.8
76.3
80.4
79.4
79.9
75.4
78.5
77.4
79.3
79.6
78.5
78.7
78.2
80.0
79.8
17.2
9.2
11.7
17.8
17.3
14.0
12.4
19.3
17.4
11.3
11.3
16.6
18.0
14.9
19.9
14.9
17.0
12.7
13.6
48.4
40.6
42.4
47.0
49.0
41.9
37.9
50.5
48.8
37.1
41.3
46.4
44.3
45.8
48.9
43.8
46.0
37.9
39.9
Table 2 continued
Station
Belleville
Big Bend
Bondville
Brownstown
Carbondale
Champaign
DeKalb
Dixon Springs
Fairfield
Freeport
Monmouth
Olney
Peoria
Perry
Rend Lake
Snicarte
Springfield
St. Charles
Stelle
Total Solar
Average
Radiation
Relative
(MJ/m2)
Humidity (%)
404.5
398.8
437.0
408.1
444.0
411.6
379.2
392.6
432.7
390.5
406.4
439.9
388.4
405.4
434.8
412.8
396.3
364.5
391.7
68.2
70.8
73.5
65.7
65.1
69.2
70.7
65.7
66.3
71.3
71.8
67.1
72.0
68.5
65.3
68.0
66.2
69.5
74.4
Total
Average
Precipitation Dew Point
(in)
(°F)
3.32
3.15
2.78
2.79
3.78
2.56
3.11
4.54
2.26
2.58
3.20
2.89
4.30
4.17
2.62
3.43
4.77
3.74
2.35 M
Total Potential
Evapotranspiration
(in)
37.3
30.7
33.5
35.0
36.5
31.7
28.0
38.2
37.0
27.6
31.8
35.1
34.8 M
34.6
36.7
32.7
34.2
27.9
31.6
2.9
2.43
2.66
2.82
3.21
2.52
2.20
2.80
3.07
2.14
2.54
2.89
2.45 M
2.78
3.03
2.82
2.70
2.12
2.3
_______________
Notes:
M = Missing data.
6
Ave Soil
Ave Soil
Ave Soil
Ave Soil
Temperature Temperature Temperature Temperature
at 4" under at 8" under at 2" under at 4" under
Sod (°F)
Sod (°F)
Bare Soil (°F) Bare Soil (°F)
48.4
42.1
44.6
47.8
50.0
47.2
40.4
50.4
49.5
42.8
42.7
48.2
44.1
46.5
49.7
47.2
47.5
41.8
42.2
48.1
42.2
44.5
47.0
49.8
47.0
40.9
51.1
49.3
40.7
42.2
48.3
44.8
46.6
50.5
47.3
46.3
41.7
42.1
48.5
42.4
45.1
46.6
49.3
46.6
42.3
51.2
49.9
41.2
42.8
48.8
43.2
46.3
50.1
47.3
45.9
41.2
41.5 M
46.8
42.2
45.3
46.7
49.4
46.6
41.8
48.3
45.8
38.3
43.2
48.6
43.5
46.5
50.4
47.4
45.9
42.2
40.9
Figure 5
March soil moisture levels at ICN stations.
2 in,
4 in, and
8 in
7
Figure 5
March soil moisture levels at ICN stations.
2 in,
4 in, and
8 in
8
OTHER PRECIPITATION NETWORKS
Cook County. During March 2017, precipitation
was well above normal (Figure 6b). On March 20, the
gage at site 16 in Palos Park, IL recorded a one-year
recurrence interval event with a storm total amount of
1.63 inches in three hours.
Total monthly precipitation amounts were greatest
in the south-central region of the network and lowest
along the northern edge of the network. Precipitation
values ranged from 5.11 inches at site #17 (near
Laramie Ave and W 115th St) to 2.96 inches at site #1
(Northbrook, near Landwehr Rd and Willow Rd). The
March 2017 network average of 4.19 inches is about
179 percent of the 27-year (1990 –2016) March network
average of 2.34 inches. The Illinois State Water Survey
operates this 25-station precipitation network funded
by the U.S. Army Corps of Engineers.
—Erin Bauer
Imperial Valley. Precipitation during March 2017
was well above average (Figure 6a). Precipitation
amounts were largest along the northern edge of the
network and a region in the center of Mason County,
northeast of Easton, IL. The smallest gage totals were
along the western edge of Mason County. Monthly
gage totals varied 1.26 inches across the network, from
2.33 inches (site 13) east of Havana to 3.59 inches
north of Manito (site 2). The 1981–2010, 30-year
average precipitation amounts for March at Havana and
Mason City are 2.81 and 2.49 inches, respectively. The
March 2017 network average of 3.03 inches is about
143 percent of the 24-year (1993-2016) IVWA March
network average of 2.11 inches. The Imperial Valley
Water Authority funds this 20-station precipitation
network operated by the Illinois State Water Survey.
0TWLYPHS=HSSL`>H[LY(\[OVYP[`
7YLJPWP[H[PVUPUJOLZ
4HYJO
a. Imperial Valley
:JHSLVM4PSLZ
b. Cook County
4HYJO
Figure 6
Long-term raingage network precipitation totals (inches) for March 2017
9
SURFACE WATER INFORMATION
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
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-February water levels at
26 reservoirs for which levels were reported last
month and this month, reported end-of-March water
levels were lower at three reservoirs, higher at 18
reservoirs, and about the same as at the end of last
month at five reservoirs. For the 27 reservoirs with
measurements reported at the end of March, water
levels were below the normal target pool or spillway
level at seven reservoirs, at about the full pool level at
eight reservoirs, and above the seasonal target or fixed
spillway levels at 12 reservoirs.
Major Reservoirs. Compared to water levels at
the end of February, at the end of March the water
level at Rend Lake was 0.2 feet higher, Carlyle Lake
was 0.4 feet higher, and Lake Shelbyville’s level
was 0.1 foot lower. At the end of March, Rend Lake
was 1.7 feet above the spillway level, Carlyle Lake
was 0.4 feet above the April 1 target level, and Lake
Shelbyville was 1.7 feet below the April 1 target level.
(Carlyle Lake and Lake Shelbyville target operating
levels increase from March to May.)
Great Lakes. Current month mean and endof-month values are provisional and are relative to
International Great Lakes Datum 1985. The March 2017
mean level for Lake Michigan was 579.2 feet. The
monthly mean level one year ago (March 2016) was
579.4 feet. The long-term average lake level for March
is 578.4 feet, based on 1918-2015 data. In this period
of record, the lowest mean level for Lake Michigan for
March occurred in 1964 at 576.1 feet, and the highest
level for March occurred in 1986 at 581.1 feet. The
month-end level of Lake Michigan was 579.3 feet. All
values are provided by the USACE Detroit District.
—Bill Saylor
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 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. Peak stage is represented
here by morning readings posted daily by the USACE
or the National Weather Service. Flood stage is defined
locally for each gage location.
Provisional monthly mean flows for 26
streamgaging stations located throughout Illinois are
shown in 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. Long-term mean flows for
each month are published by the USGS. The month’s
median flow for each station listed in Table 4 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 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 aggregated statewide, using
the available monthly mean data shown this month
in Table 4, was below the median value for March
(approximately 60 percent of the median) and below
the long-term mean for the month (about 50 percent of
the mean). Monthly mean discharge values were in the
much below normal to normal range for the calendar
month. Streamflow conditions across central and
south-central Illinois were drier during most of March
than Table 4 values would suggest, as flows were
augmented by precipitation at the end of the month.
10
Table 3. Peak Stages for Major Rivers during March 2017
River
Station
River
mile*
Flood stage
(feet)*
Peak stage
(feet)**
Date
Illinois
Morris
La Salle
Peoria
Havana
Beardstown
Hardin
263.1
224.7
164.6
119.6
88.6
21.5
16
20
18
14
14
25
15.3
21.3
13.2
12.5
11.5
22.4
31
31
31
31
31
11
Dubuque
Keokuk
Quincy
Grafton
St. Louis
Chester
Thebes
579.9
364.2
327.9
218.0
180.0
109.9
43.7
17
16
17
18
30
27
33
16.6
13.3
16.3
17.2
16.4
18.8
N/A
04
08
08
10-11
11
11-12
N/A
Mississippi
Ohio
Cairo
2.0
40
37.6
10
________________
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 4. Provisional Mean Flows, March 2017
Station
Drainage
area
(sq mi)
Years
of
record
2017
mean flow
(cfs)
Long-term flows
Mean*
Median
(cfs)
(cfs)
Flow condition
Rock River at Rockton
6363
81
8613
7365
7851
normal
Rock River near Joslin
9549
73
11,700
11,090
9725
normal
Pecatonica River at Freeport
1326
97
1457
1765
1722
normal
Green River near Geneseo
1003
77
686
1081
902
normal
Edwards River near New Boston
445
78
219
528
413
below normal
Kankakee River at Momence
2294
99
3047
3341
3201
normal
Iroquois River near Chebanse
2091
92
1482
3170
2742
below normal
Fox River at Dayton
2642
97
3422
3363
2866
normal
Vermilion River at Pontiac
579
72
463
758
674
normal
Spoon River at Seville
1636
99
748
1727
1287
below normal
LaMoine River at Ripley
1293
92
281
1317
917
much below normal
Bear Creek near Marceline
349
72
87
375
247
below normal
Mackinaw River near Congerville
767
67
739
948
739
normal
Salt Creek near Greenview
1804
74
988
2106
1729
below normal
Sangamon River at Monticello
550
103
264
713
606
below normal
South Fork Sangamon near Rochester
867
66
133
989
708
much below normal
Illinois River at Valley City
26,743
77
23,190
34,480
30,487
normal
Macoupin Creek near Kane
868
87
317
876
576
below normal
Vermilion River near Danville
1290
94
957
1726
1442
below normal
Kaskaskia River at Vandalia
1940
46
594
2958
2498
much below normal
Shoal Creek near Breese
735
72
152
958
729
much below normal
Embarras River at Ste. Marie
1516
102
516
2185
1981
much below normal
Skillet Fork at Wayne City
464
96
295
821
728
below normal
Little Wabash below Clay City
1131
101
508
1747
1470
below normal
Big Muddy at Plumfield
794
45
598
1355
1139
below normal
Cache River at Forman
244
92
331
620
436
below 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 = 90-100% 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 2015.
11
Percent
Days of
chance of data this
exceedence month
42
41
56
67
78
56
77
39
65
77
90
80
50
76
82
90
67
70
70
90
92
90
74
81
79
73
31
31
31
31
31
31
31
31
31
31
31
31
31
31
31
31
31
31
31
31
31
31
31
31
31
31
Table 5. Reservoir Levels in Illinois, March 2017
Reservoir
County
Normal pool
or target
level (feet)
Current level
difference from normal
or target (feet)
Monthly
change
(feet)
Average difference
from normal
or target (feet)
Years
of
record
February
reported pumpage
(million gallons)
Altamont
Effingham
582.0
-0.1
+0.2
-0.6
33
5.1
Bloomington
McLean
719.5
-0.5
-0.7
-0.8
30
N/A
Carlinville
Macoupin
N/A
-1.3
+0.8
-0.1
32
21.7
Carlyle(1)
Clinton
443.0
+0.4
+0.4
+1.0
39
N/A
Decatur(1,3)
Macon
612.5
+0.9
+0.8
+0.9
33
852.2
Evergreen(4)
Woodford
720.0
+0.3
+0.3
-1.1
26
N/A
Glenn Shoals(2)
Montgomery
590.0
+0.3
+0.3
+0.2
22
w/Hillsboro
Highland
Madison
500.0
+0.2
+0.2
+0.2
28
26.1
Hillsboro(2)
Montgomery
589.0
+0.3
+0.3
+0.1
22
25.6
Jacksonville(2)
Morgan
644.0
N/A
N/A
-0.1
16
w/Mauvaise Terre
Kinkaid
Jackson
420.0
0.0
+0.2
+0.2
28
41.1
Lake of Egypt
Williamson
500.0
+0.3
+0.5
+0.2
23
N/A
Mattoon
Coles
632.0
0.0
0.0
-0.1
23
w/Paradise
Mauvaise Terre(2)
Morgan
588.5
N/A
N/A
+0.1
20
no meter
Mt. Olive (new)
Macoupin
600.0
0.0
N/A
-0.5
13
w/Mt. Olive (old)
Mt. Olive (old)
Macoupin
654.0
0.0
+0.3
-0.2
19
4.5
Pana
Christian
641.6
0.0
-0.1
-0.4
33
N/A
Paradise
Coles
685.0
0.0
0.0
0.0
27
50.2
Paris (east)
Edgar
660.0
+0.1
0.0
-0.1
32
Not PWS
Paris (west)
Edgar
660.1
+0.1
0.0
+0.2
22
w/Paris (east)
Raccoon(1)
Marion
477.0
+0.5
+0.3
N/A
N/A
93.0
Rend
Franklin
405.0
+1.7
+0.2
+3.7
39
N/A
Salem(3)
Marion
546.5
-0.3
+0.7
-0.2
22
20.3
Shelbyville(1)
Shelby
594.0
-1.7
-0.1
+0.4
39
Not PWS
Sparta(3)
Randolph
497.0
-0.6
+0.7
-0.7
19
N/A
Spring(3,4)
McDonough
654.0
+0.4
+0.4
+0.1
33
45.7
Springfield(1,3)
Sangamon
559.6
0.0
+0.4
-0.5
33
505.0
Taylorville
Christian
590.0
-0.3
+0.2
0.0
24
56.0
Vermilion(4)
Vermilion
581.7
0.0
0.0
-0.2
31
178.6
_______________
Notes:
Normal pool and target level datum is NGVD 1929.
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.
12
GROUNDWATER INFORMATION
Comparison to Previous Month. Shallow
groundwater levels in all 14 wells were above those of
the previous month. Levels averaged 1.1 feet above and
ranged from 0.1 to 5.7 feet above February levels.
Comparison to Same Month, Previous Year.
Shallow groundwater levels in March were below levels
measured one year ago. Levels averaged 1.0 foot below
this month and ranged from 4.5 feet below to 2.0 feet
above levels of March 2016.
—Ken Hlinka
Comparison to Average Levels. Shallow
groundwater levels in 14 observation wells, which are
remote from pumping centers, were above normal for
the month of March. Levels averaged 0.1 foot above
and ranged from 3.6 feet below to 3.2 feet above
normal levels (Table 6). One well, Boyleston (Wayne
County), reported its lowest measurement for March.
Table 6. Month-End Shallow Groundwater Level Data Sites, March 2017
Number
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
Well name
Galena
Mt. Morris
Crystal Lake
Fermi Lab
Good Hope
Snicarte
Coffman
Greenfield
Janesville
St. Peter
SWS #2
Boyleston
Sparta
SE College
Bondville
County
JoDaviess
Ogle
McHenry
DuPage
McDonough
Mason
Pike
Greene
Coles
Fayette
St. Clair
Wayne
Randolph
Saline
Champaign
_______________
Notes:
* Lowest level of record for the month
N/A = Data not available.
Well depth
(feet)
25.00
55.00
18.00
17.00
30.00
42.00
28.00
20.70
11.00
15.00
80.00
23.00
27.00
11.00
21.00
Deviation from
This month’s reading 15-year avg. Period of record
Previous
(depth to water, feet) level (feet)
avg. (feet)
month (feet)
Previous
year (feet)
19.66
16.63
3.44
1.41
5.35
35.32
12.28
12.63
5.46
1.17
10.91
* 6.03
NA
1.96
3.34
+0.86
+3.44
+1.00
+3.32
-0.19
+2.28
-2.77
-2.86
-0.62
-0.05
+1.32
-3.26
NA
-0.41
-0.68
+1.61
+2.52
+1.16
+3.16
+0.63
+1.79
-3.09
-4.57
-0.84
+0.42
+2.75
-3.60
NA
-0.52
-0.78
+0.16
+0.78
+0.09
+5.71
+1.76
+0.22
NA
+1.38
+0.16
NA
+1.54
+0.09
NA
+1.07
+0.65
+0.06
-3.55
-0.26
+2.02
-1.55
+1.29
-1.67
-4.45
-0.71
+0.29
+1.10
-2.53
NA
-1.96
-2.41
Averages
+0.10
+0.05
+1.13
-1.02
Data sources for information in this publication include the following:
CPC - Climate Prediction Center, http://www.cpc.ncep.noaa.gov/index.php
ISWS - Illinois State Water Survey, http://www.isws.illinois.edu
MRCC - Midwestern Regional Climate Center, http://mrcc.isws.illinois.edu
NCDC - National Climatic Data Center, http://www.ncdc.noaa.gov
NWS - National Weather Service, http://www.nws.noaa.gov
USACE - U.S. Army Corps of Engineers, http://rivergages.com, http://www.lre.usace.army.mil/greatlakes/hh
USGS - U.S. Geological Survey, http://waterdata.usgs.gov/il/nwis
WARM - Water and Atmospheric Resources Monitoring Program, http://www.isws.illinois.edu/warm
13
Illinois State Water Survey
2204 Griffith Drive • Champaign, IL 61820
Tel (217) 333-2210 • www.isws.illinois.edu