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  • Floodplain Management

    Photo: Flooding inundates large areas of Marana and unincorporated Pima County during the January 1993 event on the Lower Santa Cruz River.In order to minimize the threat to life and property from flooding and erosion hazards, the goal of the Floodplain Management Division is to provide residents of unincorporated Pima County with up to date floodplain information, establish appropriate development requirements and provide timely assistance to individuals with drainage questions or concerns. This includes ensuring that any new development within the floodplain is safe from flooding and erosion hazards, does not adversely impact adjacent properties, and maintains the integrity of the floodplain.

    Another important goal is protecting natural resources within floodprone areas. Floodplains typically support important riparian ecosystems and associated wildlife. These riparian areas are also important for their role in mitigating flood hazards by maintaining stable flood flow conditions, providing natural erosion control, as well as by promoting recharge into underground aquifers. As such, it is beneficial to all residents of Pima County that these critical resources are protected and maintained.

    One of the ways Floodplain Management accomplishes these goals is by implementing floodplain regulations contained in the Pima County Floodplain Management Ordinance. The Ordinance was developed to conform with the National Flood Insurance Program administered by the Federal Emergency Management Agency  (FEMA), which allows residents of Pima County to receive flood insurance. In addition, the Ordinance includes provisions regarding the construction of buildings and other man-made structures within regulatory floodplains. The Ordinance applies only to those areas prone to flooding where the peak discharge is 100 cubic feet per second or greater, or prone to sheet flooding. In other areas, the Ordinance does not apply, however other ordinances such as the Grading Ordinance may apply.

    Flood Insurance

    You can't control the weather, but you can prepare for it.If your home is in a federally-mapped floodplain and you finance it with a loan backed by the federal government, flood insurance is mandatory. Even when not required, the District recommends purchasing flood insurance for any structure that may be impacted by flooding.

    Prior to purchasing a new home or property always confirm the floodplain status of the property. You can either do this yourself by contacting our office or ask your realtor to provide the information. Additional information can be found on the Flood Insurance page.

    Floodplain Information

    The District encourages residents to become familiar with the flood related hazards impacting their property or property that they are considering purchasing.  District staff is available to discuss flood hazard issues at our customer service counters.

    In addition, some flood hazard information is available on-line:

    NOTE: Specific questions about the flood hazard map, the Flood Hazard Information Sheet and/or the regulatory status of a wash cannot be answered via e-mail or over the phone. Please visit our office with this type of question. Other detailed questions may also require you to visit our office, where we may more accurately serve you with the wide array of resources at our disposal. If you wish, feel free to call us to determine whether or not you need to come in to our office for service.  The District phone number is (520) 724-4600.


    For more comprehensive information related to obtaining a floodplain permit, please visit the Permitting Page.

    To assist you in permitting, planning and constructing your single-lot improvements, please review the District’s Floodplain Use Permit Application Guide.

    The District has created a Subdivision and Development Review page to assist the developers and engineers in providing the District with all of the information necessary to facilitate the preparation and review of subdivision and commercial project permits.

    The District issues floodplain use permits in unincorporated portions of Pima County. Floodplain use permits for properties in the City of Tucson, and the Towns of Oro Valley, Marana and Sahuarita may be obtained by contacting that jurisdiction’s floodplain management office. There are currently no federally mapped floodplains within the City of South Tucson, although there may be local drainage issues that warrant attention.

    A floodplain use permit is a document issued by the District that authorizes a specific improvement within a regulatory floodplain or erosion hazard area. Regulatory floodplains include areas along any wash with a base flood discharge that equals or exceeds 100 cubic feet per second, and areas subject to sheet flooding.  Virtually all man-made structures or improvements constructed within regulatory floodplains or erosion hazard areas require Floodplain Use Permits prior to beginning construction.  These include: all structures, additions, fencing, walls, pools, drainage improvements or modifications, erosion control measures, and some temporary construction.

    Permit applicants, engineers and developers are encouraged to visit our Resources page for helpful information designed to make preparing documents necessary for obtaining an FPUP easier.  Engineers and developers are also encouraged to incorporate Low Impact Development/Green Infrastructure practices into their designs.

    Drainage Complaints

    Drainage concerns involving potential floodplain violations within unincorporated Pima County should be reported to the District for investigation.  A drainage violation occurs when any unpermitted activity diverts, obstructs, impedes or otherwise changes the regulatory floodplain if it creates a hazard to life or property.  Other violations may include improvement constructed not in accordance with the conditions of a permit or the Ordinance.  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.

    Please note that some flooding, called nuisance drainage, is not within the regulatory authority of the District, and must be dealt with by individual property owners.  Water harvesting may be a solution to nuisance drainage problems.

    Drainage complaints enable the District to identify potential flooding problems that may warrant measures to alleviate the problem. If you observe a potential violation or if you think that a drainageway that is owned or maintained by Pima County requires maintenance, please contact the District.

    Long Range Planning

    Through the application of sound floodplain management principles during the planning process, The District achieves substantial flood hazard prevention before specific development is proposed or lot densities are established. These principles are applied during the County’s Comprehensive Plan Amendment and Rezoning processes, as well as through courtesy reviews of projects in neighboring jurisdictions including Marana, Oro Valley, Sahuarita, the City of Tucson and adjacent counties. In addition, Floodplain Management staff reviews State Land Permit Applications, minor land subdivision applications, variance requests, and other requests in order to ensure that these proposals are compatible with the Ordinance.  Staff is available to meet with applicants to ensure that proposed development conforms to sound floodplain management principles.

    Another component of floodplain management is coordinating the long range plan for the District. Under the umbrella of the Community Rating System (CRS), the tasks and functions of the District are evaluated in order to determine their effectiveness.  To date, this has resulted in the District’s Class 5 CRS rating by FEMA.

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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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