Missouri collects water use data to better understand and manage the state’s water inventory. This data shows what water is being used for (such as municipal, agricultural, hydroelectric, etc), which regions of the state use the most water, and the demand placed on each source of water (such as an aquifer, lake, or stream). With adequate data, we are able to monitor the health of our water sources and provide data for hydrologic and geologic research. Though the amount of available water can be determined from geology and meteorology, water demand can only be calculated by data provided by Missouri’s Major Water Users. 

Irrigation system being used agricultural needs

A Major Water User (MWU) is any person or entity that has the capability of producing a large amount of water (100,000 gallons per day or ~70 gallons per minute) with all their combined wells or surface intakes. This water can be from either groundwater via a well, or surface water from a stream, river, lake, pond, or spring. Major Water Users are required by law to report the volume of water they use each year. Major Water Users are required by law to report the volume of water used by March 31 of the year following the usage.

How does this benefit me?

The MWU program helps defend the water rights of Missouri citizens and ensure that regulation and permits are not needed. Unlike many of its neighbors to the West, Missouri is a riparian water law state, meaning that a landowner has a right to reasonably use water sources that flow across or next to, or lie below their property. In other words, Missouri citizens have the right to draw as much water as they need, for whatever purpose they have, as long as it does not negatively impact others.

Many of our water sources, such as the Missouri River or the Ozark Aquifer, are shared between neighboring states that do regulate their water use. If one or more of these states believe they need more water, one option they could take is sue the State of Missouri to attempt to limit its water usage and thus allow more water to flow to the neighboring states. Water use data establishes Missouri’s need for that water, and protects the riparian water rights of its citizens. Missouri cannot show its need for water without documented data to back up that claim.

Water use data is also used to update the Missouri Water Resources Plan. The plan allows the Water Resources Center to prepare for the future challenges by examining the current state of water in Missouri. From these analyses we can identify where water is needed, where water is abundant, and areas that may have future water shortages. With this knowledge we are then able to build the infrastructure needed before there is ever a problem. Water demand primarily data comes from MWU data. If your water use is not known, then it cannot be taken into consideration when planning these projects. Missouri Water Resources Plan.


Missouri is becoming like other states to the west, where the government tells farmers how much water they can use.

Unlike many of the western states, Missouri has an abundance of water resources and does not have a need to regulate water usage. These resources include, but are not limited to: the Mississippi and Missouri Rivers, the Ozark Aquifer, several alluvial aquifers, and a large amount of precipitation. As long as these resources are not overstrained, there is no need for regulation or permitting.

If I report my data, the department will start restricting my water use. 

There is no legislation enabling the department to restrict water use. All MWU have important needs for their water, and the state of Missouri has no plans to limit that use. As long as Missouri’s water sources are not overstrained, there is no need to regulate water use. If you are concerned about future water laws, please contact your state legislator. The General Assembly creates the laws that the department is tasked with fulfilling and abiding by.

I don’t need to report because my wells are not metered or I don’t know exactly how much water I use.

Most wells in Missouri are not metered, so exact numbers are nearly impossible to determine. Estimations are acceptable when submitting your report, and there will be a place to mark if your values are estimations or exact volumes. You can also contact MGS for help in estimating your water usage. Estimated data is better than no data at all. 

This is a water permit program.

While Major Water Users must register to submit reports, this is not a permitting program. The MWU program is established to simply gather water use data. It is not an enforcement or regulation program.

I don’t want to pay fees to report my data.

While other states may have fees associated with registering and/or reporting their water usage, it is absolutely free to report water usage in Missouri. There are no fees or monetary penalties associated with Missouri MWU reporting.

My data will be used to begin taxing my water use.

The MWU program is operated by the Missouri Geological Survey who use the data for scientific, engineering, and statistical purposes only. Missouri currently has no intention of taxing water use.

The State Water Plan will prioritize who gets water, and the farmers will be the first to be restricted.

One of the main goals of the water plan is to prepare Missouri for extended droughts. We can identify areas at risk and assist with infrastructure planning to minimize the effects of drought to both the public and agriculture sectors. By reporting your water needs, we can better prepare for the future by understanding the water need of Missouri’s citizens, industry and municipalities. Missouri Water Resources Plan.