Water Resources Center
Groundwater-Level Observation Well Network
Groundwater is one of Missouri's most abundant and important natural resources. In many areas it provides nearly all of the water that is used for private and public water supply. In other areas it mostly supplies rural residents and farm needs. The Missouri Department of Natural Resources has been monitoring groundwater levels throughout Missouri since the mid-1950s. The network is operated by the department's Water Resources Center, and currently consists of more than 160 wells that vary from less than 30 feet deep to more than 1,800 feet deep. They monitor aquifers ranging from shallow, unconfined alluvial and glacial drift aquifers to deep confined bedrock aquifers. Some of these were constructed by the department specifically for measuring groundwater levels. Most, however, began as water supply wells whose use was later discontinued. They subsequently were loaned or donated to the department by cities, rural water districts, businesses, and private individuals who no longer needed them for supplying water.
The groundwater-level changes recorded at these installations are caused by many things; some natural and some man-induced. Naturally-occurring events that affect groundwater levels can include precipitation, changes in river stage, drought, earthquakes, barometric pressure changes, and tidal effects. Man-induced changes are generally caused by water wells producing large quantities of groundwater.
Additional groundwater-level observation wells were added to the network during 2008, 2009 and 2010 to bring the total to approximately 164 wells. Several new wells that penetrate the Missouri River alluvial aquifer have been added to the network. The Missouri River and its alluvial aquifer provide drinking water to more than half of Missouri’s population, and its importance as a water supply source for agriculture, industry, and recreation as well as public water supply cannot be over stressed. Additional observation wells are being placed in areas of high groundwater use to help better document water-level changes caused by all types of development. In June 2008, two new observation wells were drilled in the city of Wildwood to monitor groundwater-level changes in that rapidly developing part of western St. Louis County. Other observation wells will be placed in areas not currently monitored to help fill data gaps. Several of the wells are being placed in areas far from significant groundwater use to monitor the natural changes in groundwater level under ambient conditions.
Real time precipitation data are now being collected at more than 30 of the observation wells. These wells have been equipped with tipping-bucket rain gauges that measure and record each 0.01 inch of rainfall. Wells where precipitation data are collected are indicated with the letter ‘P’ on the regional maps. The precipitation graphs are shown below the water level graphs.
Six wetland sites were added to the network in 2009 and 2010 (Marion Bottoms, Pershing State Park, Bee Hollow Conservation Area, Little Bean Marsh Conservation Area, Van Meter State Park and Four Rivers Conservation Area.) These sites are being monitored as part of the Missouri Wetlands Monitoring and Assessment study being conducted by the Water Resources Center and the University of Missouri in cooperation with the Environmental Protection Agency. In addition to groundwater levels, a full suite of meteorological and surface-water data is being collected at these sites. More details concerning the wetlands study can be found at http://www.dnr.mo.gov/env/wrc/wetlands.htm.
A new addition to the website is the creation of strathydrographs for approximately 110 of the observation wells. These are downloadable graphics that combine well site subsurface geology, aquifer hydrogeology, well construction, earliest water level information, and long-term water level trend on a single illustration. These will allow viewers a better understanding of what the water level data is showing, and how it relates to the aquifer.