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Florence FRS

Florence Flood Retarding Structure

Rehabilitation Fact Sheet


  1. Florence Area Watershed Flood Control District
  2. Florence-Coolidge Natural Resource Conservation District

Project Location: Central Pinal County, Arizona

Authorization: Watershed Protection and Flood Prevention Act, Public Law 83-566, as amended, and Public Law 106-472, Small Watershed Rehabilitation Amendments of 2000.

Project Summary:

The Florence Flood Retarding Structure (FRS) was originally constructed by the Soil Conservation Service (now the Natural Resources Conservation Service–NRCS) in 1965.  It is currently operated and maintained by the Florence Area Watershed Flood Control District.  The five-mile-long, 20-foot-high earthen structure provides flood protection to the Town of Florence, Arizona, including:

  • 17,000 residents

  • Arizona State Prisons facilities

  • the Central Arizona Project Canal and Florence-Casa Grande Canal,

  • streets and highways, residential and commercial properties and 5,000 acres of Prime Farmland. 

The FRS has developed safety deficiencies since the time of its construction, including embankment cracking and emergency spillway capacity.  To address the embankment cracking deficiency, the project Sponsors, with assistance from the NRCS, completed a dam repair project in 2006.  The Sponsors have also completed a Supplemental Watershed Plan and Environmental Assessment (Plan/EA) which calls for rehabilitation of the FRS to provide for continued flood protection while meeting current dam safety and performance standards.  The total flood damage reduction benefit from the Florence FRS is estimated at $54 million.