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El Vado Wash Drainage Improvements

Study status:  Letter of Map Revision (LOMR) approved by FEMA. The new mapping is effective as of April 21, 2020. Phase 1 improvement plans are in progress.


This project is potentially the first of the drainage infrastructure improvements recommended by the Airport Wash South Basin Management Study (AWBMS). In cooperation with the City of Tucson (COT), the Pima County Regional Flood Control District (PCRFCD) is preparing plans to install a Green Infrastructure Water Harvesting basin at the corner of Calle Medina and Santa Clara.

The project has also remapped the Federal Emergency Management Agency (FEMA) floodplains within the El Vado Wash Watershed.

For more information contact:
Janice Hughes, PE, Civil Engineer
(520) 724-4600

Scope of Work

The first part of this project submitted to FEMA updated Hydrologic and Hydraulic Modeling completed with the AWBMS. This revised mapping removed 8.49 acres from the FEMA Floodplain.

The second part of this project is investigating ways to improve the drainage within the watershed. Our first project will be a Green Infrastructure, Water Harvesting basin adjacent to the New Hope Methodist Church at Calle Medina/Santa Clara. Construction is anticipated during FY 2022/2023. PCRFCD is currently working with City of Tucson to work out operations and maintenance agreements.

The Flood Insurance Rate Map (FIRM) for a community depicts the Special Flood Hazard Area (SFHA), the area that has been determined to be subject to a 1 percent or greater chance of flooding in any given year (i.e., 100-year floodplain). The FIRM is used to establish whether flood insurance is required, flood insurance premium rates, and to help the community with floodplain management.

The Pima County Regional Flood Control District (District) on behalf of the City of Tucson (City) applied for a Letter of Map Revision (LOMR) from the Federal Emergency Management Agency (FEMA) to revise FIRM panels 04019C2288L and 04019C2880L to reflect improved data and modeling techniques. FEMA has agreed to revise the SFHA for the areas surrounding the El Vado Wash effective April 21, 2020. The proposed LOMR will result in:
1) Narrowing the width of the SFHA;
2) removing 8.49 acres of land from the SFHA, and
3) decreasing the water surface elevation of the flooding for those areas that remain in the SFHA.

The map revisions may remove the need for property owners in the area to carry federal flood insurance or reduce the flood insurance rate on their home. Home owners should contact their mortgage holder or insurance company prior to April 21, 2020 to verify the impact of this LOMR. Floodplain revision maps are below:
If you have any questions or concerns about the proposed project or its effect on your property, please contact Janice Hughes, Civil Engineering Manager, with the District at (520) 724-4600, or Elizabeth Leibold, Civil Engineer with the City at (520) 837-4934, Monday through Friday from 8:00 a.m. to 4:00 p.m.

Si necesita ayuda con la traducción, favor de comunicarse con Francisco Ramirez al número (520) 724-4600.
A public meeting discussing this and the other recommended projects from the AWBMS was held at the Desert Diamond Casino on June 25, 2014. Additional mailings and outreach will be forthcoming as the project progresses. 

If you have any questions about the project please contact Janice Hughes, PE, Project Engineer, Pima County RFCD at 724-4600 or Janice.hughes@pima.gov.
August 23, 2005 - Photos by Eric Griffin