Learn About My Assessment

Properties that flooded in 1913 and now receive protection from the Miami Conservancy District’s flood protection system pay an annual assessment to cover the necessary, ongoing maintenance of the dams, levees, storage basins, and related parts of the flood protection system. Assessments are based on property values and the appraisal of flood protection benefits provided. The funds collected are used for the necessary, ongoing maintenance of the flood protection system.

If you are a property owner protected by the Miami Conservancy District, you can view your current assessment by checking your property tax bill from your county auditor.

UPDATE: Changes to how Miami Conservancy District assessments are determined in 2024.


Frequently Asked Questions 


What is an assessment? Is this a tax?
Properties that flooded in 1913 and are now protected by the Miami Conservancy District flood protection system pay an annual assessment calculated using several factors including property tax values established by the county auditor. 

  • Assessments are different from taxes because assessments provide a benefit such as when you are assessed for sidewalks or streetlights in your neighborhood.
  • You receive a benefit in the form of reduced risk of flooding by the Great Miami River and certain tributaries.


Why do I pay a flood protection assessment?

  • Your property flooded during the Great Flood of 1913.
  • The assessment pays for the ongoing maintenance of the integrated flood protection system that includes five dams, storage basins, 55 miles of levee, and improved channels that were constructed to protect the region. 
  • The assessment is based partly on property values determined by the county auditor. The flood protection assessments appear on annual tax bills issued by the county treasurer.


Where does the Miami Conservancy District get the authority to charge this assessment? 
MCD is organized under the Ohio Revised Code sections 6101.01-6101.90.

Helpful links: Organization | Governance | Funding | History | The Conservancy Act


Who pays to be protected?

  • Individual properties pay an annual Individual Assessment

  • Municipalities and counties pay a Unit Assessment. Property owned by a municipality or county is exempt if the property is used expressly for a government purpose such as a city hall, water treatment plant, or fire station.


How is the assessment calculated? 

Properties that benefit from the protection of the Miami Conservancy District integrated flood protection system pay an annual assessment. The methodology was developed in 1917 and has been used for more than 90 years. The assessment is calculated by multiplying a rate and benefit:



The rate is assigned annually by the Miami Conservancy District Board of Directors and is subject to approval by the Conservancy Court:

 Maintenance Rate

    • Funds are used for the ongoing operation and maintenance of the flood protection system.
    • Current maintenance rate is 2.19%. 


Capital Improvement Rate

    • Funds are used for the rehab and repair of the flood protection system.
    • The capital authorization expired in 2022 and the rate was 0.54%. It was limited to dam and concrete stability projects. 



Individual properties, counties, and municipalities that flooded in 1913, and are now protected by the Miami Conservancy District’s integrated flood protection system, receive a benefit. The benefit represents the enhanced value of the property resulting from flood protection and is computed using the following flood factors:

    • Land and building tax values of the property provided by the County Auditor. Since property values can increase or decrease over time, the Miami Conservancy District periodically performs a Readjustment of the Appraisal of Benefits to make sure the cost to maintain the flood protection system is equitably distributed.
    • A flood percentage ranging from 3 to 30%, based on the depth of flooding at the property during the 1913 flood.
    • Other applicable modifiers such as the percent of property that was flooded, the location of structures, and buildings with multiple stories.

If your property is protected by dams, storage basins, and levees, you are fully protected. If your property is protected by dams and storage basins (no levees in your community), you are partially protected, and receive less benefit.


Full & Partial Protection Maps By County:


Is this related to the county’s reappraisal?
No, it is an entirely different process, but the assessment is based partly on the value of your property.

I’m from a church/non-profit. We should be exempt.
Your property may be exempt from taxes, but it is not exempt from assessments.

Why are there two assessments, Maintenance and Capital, and what is the difference?

  • The Maintenance Assessment is used to operate and maintain the entire flood protection system of dams, levees, storage basins, and other parts of the system. 
  • The Dam Safety Assessment paid for capital improvements from 1999-2022.
  • The Capital Assessment begins in 2025 and pays for rehabilitation activities of the system.


My property floods so why do I pay an assessment to Miami Conservancy District? You aren’t protecting me.

  • If partially protected: If your property is not within a city that has levees and channel improvements, your property still receives partial protection from the work of the dams. This means that the frequency or intensity of flooding is reduced. You are charged at a partial rate not a full protection rate.
  • If fully protected: Some properties experience minor flooding because their storm sewers lack capacity or sometimes the water is rising levels from groundwater. Miami Conservancy District protects from flooding from the river.


Why do I pay twice as much as my next-door neighbor?

  • Your house—because of a difference in ground elevation—may have flooded more or less than your neighbors in 1913.
  • The 1913 flood level at each property is used to calculate the benefit and could impact the amount you pay.
  • Also, property tax values are used to calculate the benefit, so if your house’s appraised value is more than your neighbor’s, you could pay more.


My building wasn’t even here in 1913. How can you assess me?
The property flooded in 1913 and it is now protected by the Miami Conservancy District flood protection system. Properties protected by the flood protection system are assessed for the maintenance of the system.


How do you know how deep the flood was on my property in 1913?

Information from topographic mapping (property elevations) and high water elevations surveyed and recorded immediately after the 1913 flood is used to determine flood depth.


What is the flood factor/How do you determine percentage for my flood factor?

  • The flood factor is a percentage that is applied to your benefit calculation. It is based on the 1913 flood depth on your property and the type of protection you receive: either full or partial.
  • Partial protection has a “flood factor” of 3% - this is property not protected by levees.  Typically, this is land outside cities that is not protected by levees but have reduced risk of flooding because of the dams.
  • Full protection “flood factors” range from 6% to 30% and is based on the depth of flooding in 1913. This land is usually in cities that are protected by both the dams and levees to the full design of the system.


Why do I have to pay both flood insurance and a Miami Conservancy District assessment?

  • Your assessment helps pay for the maintenance of the flood protection system.
  • Insurance pays in the event you were ever flooded.
  • Some people are subject to mandatory flood insurance, but flood insurance is something that Miami Conservancy District has no control over. We only have authority over the flood protection system.
  • The flood protection system positively influences flood insurance rates.  Miami Conservancy District protected properties have reduced or avoided flood insurance needs.  Without Miami Conservancy District flood protection, you would likely have much higher flood insurance costs. 



Additional Resources