Winslow Levee

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Overview Statement

Informational Video on the Winslow Levee


The Little Colorado River (LCR) is a dynamic, unstable dry land river. It is a 356 mile meandering tributary of the Colorado River with erratic flows due to uneven snow melts and summer monsoons. The LCR has a total elevation drop of about 6,300 feet from its headwaters in the White Mountains to its confluence with the Colorado River.  

The complex hydrology of the LCR is a problem that first captured the attention of the United States government nearly a century ago. Since then, Navajo County and the City of Winslow have worked with federal and state partners to find a permanent solution.

LRC flooding has tormented Winslow and its environs for generations. The LRC’s channel form changes and the associated erosion poses an even-greater flood-related hazard than floodwater inundation. The river channel undergoes constant side to side migration and channel narrowing.

Despite Arizonas arid climate, its all of rivers frequently flood as the result of three storm types:

      Winter frontal storms that cover large areas of the state and region (late November through mid-March);

      Dissipating Pacific Ocean tropical cyclones that move over the entire state (late summer and early fall); and

      Monsoon season convective thunderstorms (late June through mid-September).  

These storms influence the type and duration of Arizonas flooding.  Decaying tropical storms and winter frontal systems are generally slow-moving, low-pressure weather systems that produce regional floods.   Monsoon thunderstorms bring flash floods which can occur within seconds to hours after the onset of rain.   These are the deadliest because of the rapid increase in water levels and swift devastating flow. 

History of Flooding

WLevee2 Quantitative measurements of early floods on the LRC (before 1950) are scanty. Prior to 1972, there were no flood gauges on the LRC in Winslow. But the greatest flood peak on the LRC occurred in December 1923 at Holbrook and was estimated to be 60,000 cubic feet per second. Before the completion of the Winslow Levee historical records of major flood flow events in the Winslow area indicate that many of these floods have resulted in significant property damage.


1878: The LCR destroyed Brigham City, the Mormon settlement that was located north of today s Interstate 40. 

1888: Eyewitness accounts from the time tell the story: "Only the tops of the cottonwoods remained above water," "The whole country seemed to be under water” or, There was water everywhere.” According to Bill Williams, a young cowboy at the time, the water rose more than 73 feet in Clear Creek, a LCR tributary near Winslow.


1905: Lumber for a new bridge washed away when the LCR  flooded.

1908: The only winter flood in which melting snow seems to have played no appreciable part.

1923: Highest ever LCR peak flows measured, inspiring La Posada builders to elevate their site by six feet. 

1926: Winslow native Lorena Shipley, better known as stage actress Norma Deane, killed in flash flood on a visit home to see her parents. 

1928: A wet August where 4.44 inches fell in Winslow. Most of this rain came in a single cloudburst on August 2 which flooded basements and destroyed the lower floor of the Old Harvey House. 

1945: The LCR flooded the railroad office with five feet of water and closed the Williamson Street underpass.


1952: Monsoons ravaged road beds and street surfaces which took weeks to repair.

1954: Stream or Street?” read the August 12 Winslow Mail headline.

1954: Families were evacuated when dikes protecting the airport runways broke.

1970: Labor Day Flood breached LCR dikes and surrounded 200 homes with water.  

1978: Easter flood overtopped LCR dikes, destroying homes, livestock and vehicles. 

1978: Christmas flood forced evacuations at 2AM Governor declared county a disaster.  

1980: Valentines Day flood caused from leak in earth-filled dike flooded homes in Bushman Acres. 

1993: New Years flood filled fifty homes with four feet of water and forced 900 people to evacuate.


2004: New Years Eve piping failure of Winslow Levee damaged Homolovi Ruins State Park.

History of Flood Protection


The LCR’s bed can move a mile over the course of a persons lifetime. Its bed and banks are composed of mobile sediment that constantly changes the channel flow based on the extent and frequency of flooding it experiences. Protecting life, safety and property from a meandering river is no easy task. For over a hundred years Winslow’s pioneers, public officials and residents have all tried to solve the persistent problem of LCR flooding.

Railroad Efforts

1908: Made extensive embankment improvements on both sides of the LCR bridge.

1924: Re-built bridge over LCR to address embankment problems.

Resident Efforts

1954: Built dikes out of old cars, dirt and cement in an attempt to restore LCR to its prior course.

City of Winslow Efforts

1925: Built a rock and sand dike 140 feet long and 4 feet high to protect a local gas plant.

1954: Sought flood protection assistance from Congress.

1971: Became responsible for operation of Ruby Wash Diversion Levee.

2015: Develops Winslow Levee Emergency Action Plan and Flood Response.

Navajo County Efforts

1937: Passed resolution to contribute funds for LCR flood risk survey.

1970s: Constructed four mile levee to protect Winslow and its environs.

1972: Installed gauges along the LCR, this area of the river’s first flood warning system.

1978: After major overtopping, declared war on the LCR.

1979: Dredged LCR to try to re-channel the river bed, tried to strengthen and lengthen dikes.

1980: Reinforced earth-filled dike that sprang a leak in three places.

1986: Built current 7.2 mile Winslow Levee that abuts the Ruby Wash Diversion Levee.

1991: Made improvements to new levee.

1993: County crews worked 24 hour shifts to repair levee breach.

1994: Installed new rip-rap.

2005: Repaired levee damage caused from desiccation cracks, root channels, rodent burrows.

2006: Asked United States Army Corps of Engineers (USACE) to update LCR Reconnaissance Study.

2008: Partnered with USACE on Feasibility Study to find permanent flooding solutions.

2008-2018: Convinced Congress to fund 50% federal share of Feasibility Studycost.

2008-2018: Funded and/or performed 50% of Feasibility Study cost activities.

2015: Helped develop Winslow Levee Emergency Action Plan.

State of Arizona Efforts

1968: Arizona Department of Water Resources (ADWR) helped USACE construct Ruby Wash Diversion Levee.

1974: Arizona Department of Transportation (ADOT) completed hydrology study for Interstate 40.

1974: ADOT designed Interstate 40 to serve as a dike.

1980: ADWR issued “Feasibility Report, Little Colorado River Flood Control Project, Winslow.”

1986: ADWR helped Navajo County construct Winslow Levee.

Federal Efforts

1937: Congress authorized survey of LCR and its tributaries in Navajo County.

1939: Congress appropriate funds for USACE to do LCR survey.

1954: US Soil Conservation Service took aerial photos of LCR in Winslow to identify flood risk.

1961: USACE researched and published report on flood control in Winslow.

1968: USACE began building the 5.3 mile Ruby Wash Diversion Levee.

1978: USACE exploded LCR with 600 pounds of dynamite to try to straighten “dog leg.”

1979: USACE directed County to raise the height of the dike behind Whipple Park by four feet.

1980: USACE helped County reinforce earth-filled dike.

1993: USACE assisted County crews to conduct emergency repairs on Winslow Levee.

1993: Federal Emergency Management Agency (FEMA) paid 75% of repair costs for Winslow Levee.

1998: USACE added three feet of freeboard to Ruby Wash Diversion Levee.

1999: USACE published report that identified federal interest in LCR flood risk management.

2008: USACE revised report on federal interest in LCR and issued Reconnaissance Study.

2015: USACE, United States Geological Survey, and National Weather Service helped develop Winslow Levee Emergency Action Plan.

2008: USACE embarked upon Feasibility Study of permanent LCR flood solutions.

2018: USACE LA District completed Feasibility Study and sent it to Headquarters for approval.

Flooding Impacts


Vulnerable Populations

Winslow has three distinct sub-populations whose social economic challenges influence their ability to respond to, cope with, recover from, and adapt to floods.  These conditions put these populations at risk for loss of life or loss of property.

Children: Winslow is home to many young families whose low incomes and lack of vehicle ownership make flood evacuation and recovery very difficult. 25% of Winslow’s residents are children. 7.1% are under 5.  One third of Winslow residents are single moms.

Elderly & Infirmed: More than 10% of Winslow residents are over 65. Many have low incomes. At least 500 are sick and live in assisted care facilities located in the 100 year flood zone. The limitations of their physical mobility and resources make their evacuation difficult.

Tribal Relocatees: As a result of the Navajo Hopi Land Settlement Act of 1974, Public Law 93-531, the federal government relocated approximately 700 Navajos and Hopis from their reservations to Winslow’s 100 year flood plain. 76% are under-employed. Limited resources and tribal disconnection challenge the ability of these families to recover from a flood.


Approximately 1,600 structures, including almost the entirety of Winslow’s critical public facilities (hospitals, schools, nursing homes, and utilities) are located in a 100 year floodplain. Expected average annual damages for the current condition due to flooding exceed $10 million dollars.

Hospital: The Little Colorado Regional Medical Center’s electrical and medical oxygen systems are vulnerable to a leave breach. Its electrical wiring and conduits are all underground. Its generators and transformers are ground level. Flood water would contaminate oxygen valves and fittings, making its medical oxygen system unusable.

Sewage: Winslow's Wastewater Treatment Facility has a micro-levee  (berm) surrounding it but the the city's sewage collection system itself is vulnerable to a flood event.  The sewages gravity system has five lift station pumps that carry Winslow's sewage from lower to higher elevations.  All five pumps are within the 100 year flood zone.

Emergency Response: Winslow's primary 911 system is located inside the Police Department in one of the lowest spots of Winslow's 100 year flood zone.  Its backup system is located in the Fire Station, a few short blocks from the Ruby Wash Diversion Levee.  A levee breech could destroy both stations, making 911 calls impossible.

Local Economy

All of downtown Winslow was built before 1935. This architectural and historic fact drives Winslow’s tourism economy.  Much of Winslow is on the National Park Service’s National Register of Historic Places - the nation’s list of historic places worth preservation.

Insurance: Federal Emergency Management Agency (FEMA) engineers mapped the Winslow’s flood zones as though no levee exists manning that Winslow property owners must carry costly flood insurance.  As great a risk as an actual flood is, for these owners, being financially underwater due to insurance premium increases can be ruinous.

Real Estate: Property owners fear that mandatory flood insurance premiums slow down their real estate market and diminish their property values. Flood insurance costs do disqualify some potential buyers from financing. Home values will increase when flood risks decrease.

Development: Winslow’s business community likens mandatory flood insurance to a boot on the neck of Winslow’s economic future. Reconstructing the Winslow and Ruby Wash Diversion Levees to remove properties from a FEMA flood plain map will remove that restraint.

Jobs: United States Army Corps of Engineers (USACE) estimates that construction of the Winslow Levee Project will create over 1,000 jobs that will generate $27 million in wages and pump $33 million into the regional economy.

National Economy

Winslow provides a critical transcontinental crossing of the LCR through which the Burlington Northern Santa Fe (BNSF) Railway threads commodities and consumer goods to and from Chicago to the Ports of Los Angeles and Long Beach. In 1853, President Franklin Pierce ordered military surveyors to chart a railroad route along the 35th parallel, across the Colorado Plateau and the LCR. Winslow’s location was selected precisely because the LCR could be traversed there and could provide water for the future railroad. Winslow is a town the railroad built.

Transcontinental Rail Freight: BNSF carries $4 million worth of freight per hour, or $35 billion per year, through Winslow. 120 double stacked trains per day, or one every 12 minutes, travel to and from the Ports of Los Angeles and Long Beach, across the LCR bridge, near the most likely failure point on the Winslow and Ruby Wash Diversion levees. Approximately 5,000 freight containers per day could be significantly delayed if a flood event were to damage the LCR bridge and disrupt the rail corridor that pulls trains through Winslow like thread through the eye of a needle.

Transcontinental Truck Freight: Interstate 40 links Port of Los Angeles to the eastern United States, carrying a daily traffic volume of approximately 30,000 vehicles.  Freight trucks constitute more than 43 percent of Interstate 40’s total traffic. This transcontinental highway runs through Winslow’s 100 year flood plain and is situated between the Winslow and Ruby Wash Diversion levees. Interstate 40 traffic through Winslow could be stopped, delayed, and re-routed if the LCR floods. 

Past Project Planning Milestones

Thousands of residents are at risk from failure or overtopping of the Ruby Wash Diversion and Winslow Levee System. Many areas would be quickly inundated with several feet of water, leading to significant public health and safety risks. In some parts of northeastern Winslow, flood depths could exceed ten feet.

The purpose of the proposed project is to reduce risk of property damages and the life, safety, and health risks caused by flooding from the LCR to the City of Winslow, surrounding community, and public and private infrastructure. The project has competed two phases of the Planning stage.

Reconnaissance Study:

The Little Colorado River Watershed, Arizona and New Mexico Reconnaissance Report was approved by the South Pacific Division (SPD) of the USACE on November 5, 1999. This study identified Federal interest in water resource issues within the LCR Watershed, including flood risk management, ecosystem and environmental restoration, storm water retention, water conservation and supply, and recreational needs.

A revised Report for the LCR Watershed was approved by SPD on August 11, 2008. The purpose of the revised document was to update and supplement the information in the previously approved Report.

Feasibility Study:

In 2008, Navajo County partnered with USACE to conduct a Feasibility Study of how to best protect Winslow from LCR flooding. Navajo County is the local sponsor of this study and has paid 50% of its cost in cash and in-kind contributions. The total cost of the Little Colorado River at Winslow Levee Feasibility Study was $5.9M.

The 49-square-mile study area study evaluates structural and non-structural alternatives (such as reconstruction of portions of the existing Winslow Levee and Ruby Wash Diversion Levee, levee setbacks, flood warning system and elevation of residential structures, and river channel conveyance improvements) for managing flood risk for the majority of City of Winslow and portions of unincorporated Navajo County from the Clear Creek confluence downstream to the northern end of the existing Winslow Levee.


Recent Key Project Milestones

DEcember 2020

Water Resource Development Act Signed into Law

LCR Levee at Winslow Authorized in Bill

February 2019

A resolution of the Navajo Count Flood Control Board of Directors, Supporting the Intent of Navajo County and the City of Winslow to Partner and Share equally in Future Costs Associated with the Planning, Engineering, Design and Construction of the Little Colorado River at Winslow, Navajo County Arizona, Flood Risk Management Project.

July 2019 

National Association of Counties adopts Resolution to make rural flood control projects more competitive for funding.


December 2018

Chief of Engineers Report


Next Steps

Navigate Federal budget and legislative processes

  • Continue rigorous coordination with USACE on project funding status
  • Coordinate with federal, state, local, tribal, and private sector stakeholders
    • Congressional advocates and committees
    • USACE; ADOT; and BNSF Railroad
    • Navajo Nation

Efforts to improve project BCR and implementation

  • Initiate Pre-Construction/Engineering and Design (PED phase)
  • Pursue Economic Validation Study if necessary

Winslow Levee Information