Floodplain FAQ

A floodplain is an area that has been designated by the Federal Emergency Management Agency (FEMA) or the City of Tucson as Special Flood Hazard Areas (SFHA). These areas are defined by the frequency of the floods they may be prone to experiencing, such as a 100-year and 500-year (1% and 0.2% chance of significant flooding). Areas and minor washes that experience peak discharge rates of 100 cfs or greater during the 100-year storm event, they are considered regulatory floodplain.

For perspective - One cubic foot per second (cfs) is about 450 gallons per minute.

There are different classifications that FEMA and the City of Tucson have when it comes to delineated floodplains.

FEMA Classifications (All zones are marked as areas at high risk of flooding – all associated with the 1% chance of occurrence on a yearly basis):

• X – Outside the two-tenths (0.2) percent annual chance floodplain.
• Zone X (Shaded) – areas of two-tenths (0.2) percent annual chance flood; areas of one (1) percent annual chance flood with average depths of less than one (1) foot or with drainage areas less than one (1) square mile; and areas protected by levees from one (1) percent annual chance flood. Also known as 500-year and 100-year floodplains with 0.2% to 1% annual
• Zone A – Areas without detailed hydraulic analyses for depths
• Zone AE – Base flood elevations determined through hydrological analysis – moderate to high flow velocities
• Zone AH – Flood depths of 1 to 3 feet (Usually associated with ponding) Base flood elevations determined
• Zone AO – Flood depths of 1 to 3 feet (Usually sheet flow on sloped terrain); average depths determined

All new habitable structures such as homes or businesses within the City of Tucson that fall within a regulatory floodplain will be required to have a Floodplain Use Permit with Elevation Certificate. This is to ensure safety to life, property, and infrastructure for the City of Tucson.

Existing or Previously Issued Floodplain Elevation Certificates can be found by:

• Entering the property/site address into Property Research Online (PRO) to see if there is a recorded elevation certificate on file as well as potential floodplain status for the property. https://pro.tucsonaz.gov/
• If no previous Elevation Certificate is found, it is possible to go through the Final Elevation Certificate Process to receive a partially completed form. The Elevation Certificate form must be completed and stamped by an Arizona Registered Land Surveyor.

How to obtain new Elevation Certificate?

• Apply for a Floodplain Use (FPU) Permit through Tucson Development Center Online Tucson Development Center Online,

For more information on floodplain elevation certificates and to obtain a blank floodplain elevation certificate, visit the Federal Emergency Management Agency's (FEMA's) FEMA National Flood Insurance Program Elevation Certificate and Instructions.

To receive written documentation of floodplain status, please use:

Option One:

• FEMA Floodplain Maps: Search your address and follow the step-by-step tutorial to determine the FEMA floodplain status of your property and download a full-scale section of a FEMA Flood Insurance Rate Map (FIRM) *Note: This is solely for FEMA delineated floodplains. The City of Tucson also has its own mapped and unmapped floodplains and flood hazard areas that will not be shown through the FEMA floodplain mapping systems.

 Option Two:

• For City of Tucson Floodplain and Flood hazard areas status, apply through Tucson Development Center Online (TDC). From there a floodplain status process can be applied for where City of Tucson Planning and Development Services Site Engineering can directly establish any floodplain status as well as possible erosion hazard properties and possible environmental resource locations within the City of Tucson city limits.
• Site Engineering direct email: Site-Engineering@tucsonaz.gov

 Flood Insurance details:

• Flood Insurance | FEMA.gov

Final Plat Requirement Notice: There are final plats across the City of Tucson that also carry the requirement that a Floodplain Use Permit be submitted in conjunction with all building permits. 

To determine if you are located within a floodplain, go to MapTucson:

1. Click “I Want to…” on the top left corner of Map Tucson
2. Click Open with the file symbol shown
3. Options will appear along the left-hand side of the screen, select “CPAS Floodplain Map”
4. It will give the prompt “Are you sure you wish to load project “CPAS Floodplain Map”? This will overwrite you existing application state.” Go ahead and click “ok”
5. Allow Map Tucson to load, then proceed to search the address of the specific property in question within the top right search bar.
6. MapTucson – Use this link for instant access to the CPAS mapping layers. These layers include all regulatory floodplain delineations used by the City of Tucson PDSD.

*Note – MapTucson does not accept fully written out address phrases, Street = ST, Drive = DR, Trail =TR, ETC. If no property address shows up, try this format: 201 N Stone AV

*MapTucson also recognizes Assessor’s Parcel Numbers, APN’s.

Final Plat Requirement Notice: There are final plats across the City of Tucson that also carry the requirement that a Floodplain Use Permit be submitted in conjunction with all building permits. 

Whenever work is proposed within a regulated floodplain or flood hazard zone, a floodplain use permit will be required. This can range from demolition work to large scale development.

Apply for a Floodplain Use (FPU) Permit through Tucson Development Center Online Tucson Development Center Online,

Upon receiving an application for a floodplain use permit, the city engineer shall, within twenty (20) working days, review the application to ensure that the site is reasonably safe from flooding, declare the application complete.

Submission Requirements:

For work within a floodplain: A Narrative/Site plan that shows exactly what work is being proposed. *Ex. Demo permits, Development Package/Site work, Exterior amenities such as pools and non-enclosed structures. *

For improvements, repairs, additions, and alterations to structures within a floodplain, a detailed cost estimate that breaks down the cost of all proposed work. This will include separate lines for materials, labor, and any warranties/fees that are associated with the work being done. *Example: Residential & Commercial addition/alterations, Solar projects, and Repairs. *

For new structures intended for commercial use as well as residential dwellings (ADUs, SFR, Duplex’s, Etc): Provide a site plan with the required finished floor elevation called out, which are provided either through a permit review from Site Engineering or determined through a drainage document/study. These permits are classified as Floodplain Use permits with Elevation Certificate.

For final plat required Floodplain Use permits: Submit the same documents used for the submission of the associated permits already submitted for. 

Planning and Development Services can be contacted at (520) 791-5550.

PDSD Site Engineering: Site-Engineering@tucsonaz.gov