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  • Floodplain Resources for Real Estate Professionals

    Pima County Regional Flood Control District
    The Pima County Regional Flood Control District (District) wants to help you understand the potential pitfalls of buying or selling properties that are in the floodplain and protect your clients in the process.

    Many people don’t realize that the disclosure requirement for FEMA floodplains is only a small portion of making truly flood smart decisions. Local floodplains, erosion hazards, and riparian habitat encompass larger areas of Pima County than FEMA mapped floodplains. 

    When buyers are planning to purchase a home or property, always confirm the FEMA and local floodplain status of the property before you purchase the property. You can do this yourself by contacting our office.

    Do I need a floodplain permit? Floodplain Management staff processes floodplain use permits for single-lot improvements, including common activities such as: site-built structures, manufactured homes, accessory structures, walls, fences, septic systems, grading. This list provides further examples of what may need a floodplain use permit. Most development activities also require a Development Services Department (DSD) Activity Permit, which should be initiated before applying for an FPUP.


    Hydrologists are available to answer your questions at the District's customer service counter Monday through Friday, from 8:00AM to 4:00PM, through walk-ins or phone inquiries. Please note that some answers may require a customer to schedule a face to face meeting to reduce miscommunication.

    Questions about properties within the City of Tucson, the City of South Tucson, or the Towns of Oro Valley, Marana or Sahuarita should be directed to those jurisdictions.


    Forms and Maps for Unincorporated Pima County

    Flood Hazard Information Form (Updated online form).
    The old PDF version of the Flood Hazard Information Form may also be completed
    Flood Hazard Map and Parcel Search
    Completed Elevation Certificates Search

    Other Local Floodplain Management Agencies

    Please contact the appropriate jurisdiction for floodplain assistance or any questions you may have about flooding issues. Property owners in unincorporated portions of Pima County and communities not indicated below should contact Pima County Regional Flood Control District.

    City of Tucson Planning & Development Services Department Flood Information
    Town of Marana Floodplain Management
    Town of Oro Valley Stormwater Utility
    Town of Sahuarita
    City of South Tucson


    When people talk about floodplains, most people think about Federal Emergency Management Agency (FEMA) floodplains. However, FEMA can't handle mapping all floodplains for the entire country, so it encourages local jurisdictions to map floodplains as well. Below are some types of floodplains that you might encounter.

    FEMA Special Flood Hazard Area (SFHA)

    The SFHA zones A, AE, AH, and AO are federally mapped floodplains shown on Flood Insurance Rate Maps (FIRMs) and are the basis for flood insurance rates. Pima County is responsible for regulating these floodplains in accordance with FEMA and National Flood Insurance Program (NFIP) requirements. Keep in mind that floods don’t read maps! Though Pima County regulates the 1% annual chance flood (100-year flood), larger floods do occur, which may create a hazard on your property that extends beyond the flood limits shown on the map.

    FEMA Other Flood Hazard Area (OFA) / Shaded-X

    FEMA OFAs are shown on FIRMs and could be one of four types of floodplain: areas of 0.2% annual chance flood (500-year flood); areas of 1% annual chance flood with average depths of less than 1 foot or with drainage areas less than 1 square mile; and areas protected by levees from 1% annual chance flood. Flood insurance is not federally mandated in OFAs, but the District always recommends the purchase of flood insurance for structures within OFAs.

    Local Floodplains

    Local floodplains are areas that carry regulatory flow (100 cubic feet per second (cfs) of water or more) and are not shown on the FIRMs. Local Floodplains are NOT mapped by FEMA. The District conducts detailed floodplain studies to map floodplains in areas of concern. Flood insurance is not federally mandated in local floodplains, but the District always recommends the purchase of flood insurance for structures within local floodplains.

    Sheetflow Floodplains

    Sheetflow floodplains are located in areas where there are either no washes or the existing washes are not large enough to convey flood waters. Flood water thus spreads out over the land surface at depths of six inches or greater in a very broad sheet of flow. Since a clearly defined channel may not exist, the path of flooding is often unpredictable and may cover large areas. This type of floodplain can be mapped by either FEMA or by the District.

    Developer Mapped Floodplains

    If you live in a subdivision, the developer may have already mapped the flood hazards in your area. Check your subdivision plat to make sure. The District or your local jurisdiction can help you with this.

    Letter of Map Amendment (LOMA)

    A LOMA is an official document issued by FEMA identifying a specific property or a specific structure as being located above the base flood elevation for the SFHA shown on the FIRM. LOMAs are used primarily to remove the federal flood insurance requirement. It is important to understand that a LOMA for a structure does not apply to the whole property or other structures on the property.

    Letter of Map Revision (LOMR)

    A LOMR is an official revision to the FIRMs issued by FEMA. LOMRs reflect changes to the 100-year floodplains or SFHA shown on the FIRMs. Changes may include modifications to Base Flood Elevations, floodplain widths, and floodways. The LOMRs are issued after a floodplain has been remapped due to a major flood event, after better mapping data becomes available, or after structural flood control improvements have been installed.

    Riparian Habitat

    Riparian habitats are water dependent ecosystems characterized by a rich and diverse group of plant and animal species. These ecosystems are vital in reducing flood peaks, enhancing water quality, and minimizing erosion hazards. Protecting riparian habitat minimizes erosion in floodplains. The plant roots help stabilize soils and reduce erosion. The plants themselves can also slow flow velocities, thereby reducing erosion and increase groundwater infiltration.

    It is important to know that when a property is impacted by mapped riparian habitat any disturbance to the riparian habitat a 1/3 acre or more, a property owner is required to mitigate for that disturbance. Disturbance is when trees, shrubs and/or grasses are removed from the riparian habitat.

    Disturbance can be from:

    • Construction
      • SFR, garages, barns, porches, ramadas
      • Fencing, driveways or sidewalks
    • Grading
      • Removal of soil
      • Placement of fill
      • Extensive raking
    • Livestock
      • Corrals, livestock trails, grazing areas
    • Humans
      • Dumping, trash, mini landfills
      • Storage of vehicles, RV’s, construction material 

    For more information please see the Technical Policy TECH 004, Delineating Regulated Riparian Habitat Disturbance


    National Flood Insurance Program (NFIP)

    Flood damage estimator from FloodSmart.govThe NFIP is a federal program that enables property owners to purchase flood insurance and is intended to curb escalating costs of repairing flood damaged buildings and their contents. Until the NFIP was enacted, this type of coverage was generally not available from private-sector insurance companies. The image at right is from an interactive flood damage estimator available at FloodSmart.gov Visit the site to see how costly floods can be!

    Am I required to obtain flood insurance?

    If your home is in a FEMA Special Flood Hazard Area (SFHA) floodplain and you finance it with a loan backed by the federal government (for example, backed by Fannie Mae or Freddie Mac), then flood insurance is mandatory.  Even when not required by law, the District always recommends purchasing flood insurance.  In Arizona, 34% of all flood insurance claims are for structures outside the FEMA floodplain! And many more structures located outside the FEMA floodplain are flooded but the owners didn't have flood insurance and thus didn't file a claim. 

    Damages resulting from flooding are usually not covered under regular homeowner or business insurance policies, specific flood insurance policies are needed for both the structure and its contents. Renters may also purchase contents coverage flood insurance. 

    Is there a discount on flood insurance in Pima County?

    Yes! By providing enhanced customer services and implementing higher regulatory standards, the District’s participation in the Community Rating System (CRS) allows residents of unincorporated Pima County to obtain lower flood insurance rates.

    In 2007, the FEMA announced that Pima County achieved a CRS Class 5 rating. This rating results in a 25% reduction in flood insurance premiums for all properties within Pima County. This designation puts Pima County in the top five percent of the 1,049 other CRS communities currently participating nationwide.


    Automated Local Evaluation in Real Time (ALERT)

    The District operates and maintains a network of real-time sensors used to collect rain and streamflow data. This network provides information to county personnel and other agencies about precipitation, stormwater runoff, and weather conditions affecting our regional watersheds, and can be an important tool to homeowners regarding estimated rainfall at a certain property. Visit the ALERT Precipitation and Streamflow Data website for more information.


    The Pima County Office of Emergency Management (OEM) has made it possible through a system called MyAlerts for the Regional Flood Control District to provide near-real-time flood alerts to Pima County residents within certain watersheds. MyAlerts serves also serves as a mass notification system that issues emergency notifications based on a geographic location. Entering your home and work addresses into your profile will ensure that OEM contacts you when alerts are sent for those areas.

    More to Consider

    Erosion Hazards

    A common hazard associated with flooding is erosion. Flowing water has potential to move soil and even large boulders from along the stream bottom as well as streambanks. Rivers, streams and washes rarely remain in a fixed location. Though a wash may be some distance from your proposed building location today, erosion may someday put that wash right at your back door, or may even undercut your structure, damaging or destroying it. The Floodplain Management Ordinance requires structures to be setback a minimum distance from regulatory washes (see table below), unless the RFCD approves an engineering analysis determining an alternative safe setback, or erosion protection is installed.

     Conveyance (cfs) Erosion Hazard Setback Requirement (EHS)
    100-500 25 ft.
    500-2,000 50 ft.
    2,000-5,000 75 ft.
    5,000-10,000 100 ft.
    >10,000 250 ft.
    Major watercourses 500 ft.


    In general, it is unlawful for any person or entity to engage in development which will divert, retard, or obstruct the flow of waters in a watercourse. A drainage violation can occur when any unpermitted activity diverts, obstructs, impedes or otherwise changes the regulatory floodplain. Additionally some people who obtain a permit, do not construct the improvement to the approved plan. This also creates a violation since the improvement constructed was not in accordance with the conditions of a permit or the Floodplain Management Ordinance.

    Arizona is a buyer beware state; a buyer is responsible for researching the property during a real estate transaction. When there is a violation on a property, if the property is sold, the violation stays with the property and NOT the former property owner. Consequently the new owner is responsible for correcting the violation. If a violation is observed, the owner of the property on which the problem is observed will be notified and required to take corrective action. Check with the District to determine if any violations exist on a property.

    Nonconforming Uses

    A nonconforming use is a structure or other improvement that was constructed in conformance with the regulations at the time of construction, but which does meet current regulations. A structure may be nonconforming due to flood or erosion hazards and usually is determined nonconforming if it was built prior to the area being mapped into a floodplain. If an applicant proposes to improve an existing, nonconforming structure and the cost of such improvements equals or exceeds 50% of the fair market value of the structure, then the new improvements, and possibly the entire building, must be brought into conformance with current floodplain requirements.

    For more information please see Technical Policy TECH 108, Guidelines for Improvements to Nonconforming Uses

    Tucson Association of Realtors (TAR) Continuing Education Class

    Does it Really Flood in the Desert?

    The Pima County Regional Flood Control District wants to help you understand the potential pitfalls of buying or selling properties that are in the floodplain and protect your clients in the process. Many people don’t realize that the disclosure requirement for FEMA floodplains is only a small portion of making truly flood smart decisions. Local floodplains, erosion hazards, and riparian habitat encompass larger areas of Pima County than FEMA mapped floodplains. Please join us for this informative course and learn how to determine whether a property is within a regulated flood hazard area and what questions to ask if it is. We’ll discuss how you can protect yourself and your clients from flood hazards and improve your reputation as a knowledgeable agent.

    TAR Facilitator: Theresa Barnabei
    Instructors: Brian Jones, Patricia Gilbert, and Joseph Cuffari
    CEC Eligible: 3 Hours - Real Estate Legal Issues
    Next class:  TBD

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    Regional Flood Control District

    201 N. Stone Avenue, 9th Fl.
    Tucson, AZ 85701

    Phone: (520) 724-4600
    Fax: (520) 724-4621

    Customer Service Hours:
    8:00AM - 4:00PM

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