Major Water User Frequently Asked Questions - PUB2337

Qualifying

What is a Major Water User?

In Missouri, a Major Water User is any surface or groundwater user with a water source and the equipment necessary to withdraw or divert 100,000 gallons or more per day, or 70 gallons per minute, from any stream, river, lake, well, spring or other water source. Additionally, any user who operates a combination of withdraws (wells, surface water pumps or diversions) that together withdraw or divert 100,000 gallons or more per day, or 70 gallons per minute, also qualifies as a Major Water User. (see Missouri Revised Statutes sections 256.400 to 256.433, RSMo). 

I have several wells that pump less than 70 gallons per minute, but when combined, they pump more than 70 gallons per minute. Am I a Major Water User?

Yes. By the definition of the law, any surface or groundwater user that has the capacity to withdraw or divert 70 gallons per minute or more from any water source is a Major Water User For example, if you have four wells, each with the maximum capacity to withdraw 20 gallons per minute, then the combined total of the four wells equals 80 gallons per minute, thus qualifying you as a Major Water User.

Our corporation has facilities in several counties. Should each facility report as a separate Major Water User?

Reporting is separated into the three water use categories: Irrigator, Non-Irrigator and Mine or Quarry. If the facilities fall under multiple categories, a Major Water Use identification number will be assigned for each water use category, however multiple facilities may report under one water use category. 

How much surface water or groundwater can I take from a water withdrawal point?

There are no state laws, regulations or policies that specify how much water may be used. However, the Water Preservation Act does set permitting and reporting requirements for exporting water outside the state. Missouri is a riparian water law state, except in cases where the end use is export outside of the state. This means all landowners touching or lying above water sources have a right to a reasonable use of those water resources. Reasonable use requires other users and landowners not be adversely impacted.

Are there any fees associated with registering as a Major Water User or reporting annual water use?

No fees are assessed to register as a Major Water User or to report annual water use.

Reporting and Registration 

How often is Major Water User registration required?

Registration is a one-time activity, required by law for all major water users. Registration is required to get a Major Water User identification number, which is needed to report water usage. Once you are registered as a Major Water User you can add, delete or transfer water withdrawal points. The necessary registration form is available below.

• Major Water Use: New User MO 780-2019

While registration is a one-time activity, Major Water Users are required to annually report water usage.  

When is annual reporting due each year?

Annual reporting is completed January 1 through March 31 for the previous calendar year. For example, water used between Jan. 1 and Dec. 31, 2025, should be reported between Jan. 1 and March 31, 2026. 

Note: To provide water use information for previous years, contact the department's Water Resources Center at 573-368-2494 or 573-368-2192.

Can I submit my annual water use data online?

Yes. The preferred method for reporting is by using the Major Water Use Information System online reporting tool. You may also submit your water use data by email at [email protected]. The same form used to register as a Major Water User also is used to report annual water use.

• Major Water Use: New User MO 780-2019

What should I do if the data on the forms I received is incorrect?

Major Water Users who requested to receive mailed reminders for annual reporting will also receive auto-populated forms with the previous year’s information, minus water usage. Please review all data for accuracy. If changes are necessary, indicate the correct information on the form and return the form to us.

What will happen if I do not submit my water use data?

The department's Missouri Geological Survey (MGS) conducts periodic reviews to assess whether individuals or entities are subject to reporting obligations. If it is determined that a party is not reporting as required by law, we proactively engage with them to provide guidance on the applicable legal requirements and to encourage compliance with reporting obligations. You may contact MGS at any time to submit water use data for prior reporting periods.  

Why does the state collect this data?

The reporting law was established to collect water use data. Understanding how much water is used by Missouri Major Water Users is critically important — it helps ensure our states water resources are managed wisely and protected for future generations. 

As of Aug. 28, 2025, permits must be obtained to export water from Missouri. Water use data will be a vital component when reviewing these applications to ensure Missourians have enough water for their needs before approving water for export outside of the state. We must know how much water is being withdrawn yearly to determine whether existing water resources are adequate to meet the current and future water use demands of Missouri citizens.

Do other states have similar requirements for water use registration?

Yes. Most states have a water use registration if they have water rights or water allocations programs.

What is my Major Water User identification number?

This eight-digit identification number is unique to each Major Water User. One or more surface or groundwater withdrawal points will be associated with this number.

Who reports water use if a water source is used by someone other than the owner?

The owner is always responsible for reporting water use. The water user may or may not be the property owner.

How do I report additional wells or withdrawal points?

Use the Major Water Use: New User MO 780-2019 form to report additional wells or contact us to request additional forms. Registration and reporting forms can be emailed to [email protected], faxed to 573-368-2193, or mailed to:

Missouri Geological Survey
Missouri Water Resources Center
PO Box 250
Rolla, MO 65401-0250