The Missouri Groundwater-level Observation Well Network

The Missouri groundwater-level observation well network 

is a series of wells across the State of Missouri in which groundwater levels are monitored in real time and periodically. The 

wells monitor the water levels in multiple key aquifers, such as 

the Ozark aquifer in the Salem and Springfield Plateaus and the 

Mississippi Alluvial Plain aquifer in the South-eastern Lowlands. 

As of 2018, 150 real-time sites are operated as a cooperative 

effort between the Missouri Department of Natural Resources 

(MoDNR) and the U.S. Geological Survey (USGS; fig. 1). This 

fact sheet describes the network and well data from the network.

Spickard

Warrensburg Wildwood

Asbury

EXPLANATION

Real-time well

Dissected Till Plains

Physiographic region

Osage Plains

Salem Plateau

Southeastern Lowlands

Springfield Plateau

St Francois Mountains

Figure 1. Missouri groundwater-level observation well network 

and physiographic regions. Modified from Miller and Vandike, 1997.

The MoDNR maintains the wells by regularly visiting each 

site. MoDNR personnel ensure that the equipment is operating 

properly and make manual water-level measurements to ensure 

that the data are accurate. MoDNR collects other well information, such as total depth, casing depth, stratigraphy, and lithology, and prepares figures that show water level in relation to 

aquifer thickness and well construction (fig. 2). Further information is available at https://dnr.mo.gov/geology/wrc/groundwater/

gwnetwork.htm.

Data are transmitted from the wells by satellite and are 

available from the USGS National Water Information System on 

the world wide web in near real time. The USGS processes these 

data, making corrections and ensuring that real-time measurements agree with the manual water-level measurements. The 

USGS makes occasional manual water-level measurements at 

key sites. Statistics are computed so that recent groundwater 

levels can be compared to historical levels to assess trends. For 

example, statistics such as daily and monthly mean water levels 

and 25th and 75th percentiles computed for the observation well 

near Spickard, Mo., completed in the glacial drift aquifer show 

that 2016–17 water levels are among the highest in the 45 years 

of record for this site (fig. 3).

Formation contacts and

depths based on well log

29243

0

100

200

300

400

500

600

700

Depth from surface, in feet

07/26/2012 07/26/2012 07/26/2012

Daily average water level in Springfield Plateau aquifer

Daily average water level in Ozark aquifer

Asbury Observation Wells

Water-Level Hydrograph

Western Interior

Plains

confining unit

Springfield Plateau

aquifer

Ozark

confining

unit

Ozark aquifer

Soil

Cherokee

Group

Warsaw Formation

Elsey Formation

Pierson Limestone

Cotter Dolomite

Jefferson City

Dolomite

Northview 

Formation

Burlington–

Keokuk Limestone

Reeds Spring

Formation

10’

105’

160’

235’

275’

375’

435’

480’

600’

Figure 2. Stratigraphy, well construction, and water levels for the 

paired wells at Asbury, Mo. Modified from Missouri Department 

of Natural Resources, 2018 (https://dnr.mo.gov/geology/wrc/

groundwater/strathydrographs/asbury_combined.pdf). Dark gray 

section of the well indicates casing interval and light gray section of 

the well indicates open interval.

401444093442001—Spickard

Depth to water, in feet below land surface

0

5

10

15

Nov. Dec. Jan. Feb. Mar. Apr. May June July Aug. Sept. Oct.

2016–17

EXPLANATION

< 10

10–24

25–75

76–90

> 90

Mean daily 

water level

November 2016–

October 2017

Mean monthly 

water level

November 2016–

October 2017

Percentile class

Figure 3. Depth to water, mean monthly water levels, and mean 

daily water levels exceeding the 75th percentile of historical water 

levels for Spickard well, Mo., November 2016–October 2017.

U.S. Department of the Interior

U.S. Geological Survey

Fact Sheet 2019–3009

ver. 1.1, March 2019
Groundwater-level data have been recorded at some sites 

for more than 50 years. These long-term data are critical for 

understanding the aquifers in Missouri. Changes in groundwater 

levels can be affected by natural and human-induced factors. 

Natural factors include precipitation, changes in river stage, 

drought, earthquakes, barometric pressure changes, and tidal 

effects. Human-induced changes are generally related to the 

pumping of groundwater.

Parts of Missouri have an abundance of groundwater, 

whereas other areas lack a reliable groundwater source. Some 

wells in the network have had an overall decline (fig. 4) in 

water levels during the period of record, such as the well near 

Warrensburg, whereas some have had increases.

2002 2004 2006 2008 2010 2012 2014 2016 2018

Year

125

130

135

140

145

150

155

Daily depth to water level, 

in feet below land surface

645

640

635

630

625

620

615

Groundwater level, in feet 

above NAVD 88

EXPLANATION

Daily mean depth to water level Period of approved data

Period of provisional data

Figure 4. Hydrograph showing groundwater-level decline at the 

Ozark aquifer well at Warrensburg, Mo.

Groundwater is one of Missouri’s most valuable natural 

resources (Miller and Vandike, 1997). Many municipalities 

rely on groundwater as their primary source of water, and more 

than one-third of the approximately 797 million gallons per day 

(Mgal/d) withdrawn in 2015 for public supply in Missouri was 

from groundwater sources (Dieter and others, 2018). Groundwater is critical for tens of thousands of rural residents, and selfsupplied domestic groundwater withdrawal was approximately 

57.5 Mgal/d in 2015. Groundwater is important for many other 

industries in the State, such as agriculture, mining, and power 

generation (Dieter and others, 2018).

Figure 5. Pivot irrigation in the Missouri Bootheel in the 

southeastern part of the State (left). Farmer inspecting the effects of 

drought on crops (right), photograph by Kelly L. Warner, USGS.

Agriculture, the largest industry in Missouri, depends on 

groundwater. During 2015, approximately 1,300 Mgal/d of 

groundwater was withdrawn for irrigation, and 16.1 Mgal/d was 

withdrawn for livestock (Dieter and others, 2018). Agriculture 

can be greatly affected by droughts (fig. 5), and the observation 

well network is valuable in assessing the effect and severity of 

droughts on groundwater supply. During the 2012 drought, many 

wells in the network, such as the Ozark aquifer well at Wildwood, had a decline in water levels (fig. 6).

2008 2009 2010 2011 2012 2013 2014 2015 2016

Year

170

180

190

200

210

220

Daily depth to water level, 

in feet below land surface

510

500

490

480

470

460

Groundwater level, in feet 

above NAVD 88

EXPLANATION

Daily mean depth to water level Period of approved data

2012 Drought 

water-level decline

Figure 6. Hydrograph showing groundwater-level decline during 

the 2012 drought in the Ozark aquifer well at Wildwood, Mo.

References Cited

Dieter, C.A., Maupin, M.A., Caldwell, R.R., Harris, M.A., Ivahnenko, T.I., Lovelace, 

J.K., Barber, N.L., and Linsey, K.S., 2018, Estimated use of water in the United 

States in 2015: U.S. Geological Survey Circular 1441, 65 p. [Also available at 

https://doi.org/10.3133/cir1441.]

Miller, D.E., and Vandike, J.E., 1997, Groundwater resources of Missouri, in 

Missouri State Water Plan Series: Rolla, Mo., Geological Survey and Resource 

Assessment, Water Resources Report Number 46, v. II, 210 p. [Also available at 

https://dnr.mo.gov/pubs/WR46.pdf.]

Missouri Department of Natural Resources, 2018, Asbury Observation Wells: 

Rolla, Mo., 1 p. 

By David C. Smith

For more information concerning this publication, contact:

Director, Central Midwest Water Science Center

U.S. Geological Survey

1400 Independence Road, MS-100

Rolla, MO 65401

(573) 308-3667

Or visit the Missouri Water Science Center Web site at: 

https://www.usgs.gov/centers/cm-water

Scott Kaden, R.G.

Groundwater Section Chief

Missouri Geological Survey–Water Resources Center

P.O. Box 250

Rolla, MO 65402

Phone: (573) 368-2194

Fax: (573) 368-2193

Or visit the Missouri Department of Natural Resources site at: https://dnr.mo.gov/

ISSN 2327–6916 (print)

ISSN 2327–6932 (online)

https://doi.org/10.3133/fs20193009