0 Occurrences 0 Occurrences 1 Occurrences 27 Occurrences 
Jackson Hole Upper Right Bank Location
City, County, and State of the levee system. Determined by the levee alignment location not the leveed area.
Moose Wilson Road, Teton County, Wyoming
System ID
Unique identifier code for the levee system using 10 or 12 numbers in length.
6005000150
Operation and Maintenance Organization
Entity responsible for day-to-day management of the levee.
USACE - Walla Walla District
Floodplain Management
Entities responsible for regulating activities that occur in areas prone to flooding.
FEMA Region 8
Oversight Organization
Entity responsible for oversight of the levee and ensuring it is maintained.
USACE - Walla Walla District
Last Assesment Date Last Risk Assessment or Formal Inspection.
4/26/2016
Levee Length
Combine length of all the levee system features including the embankments, floodwalls, closures where they exist for this system.
13.816 Miles Average Levee Height
The average height of the levee system. The levee profile viewer on the mapping window will show the actual levee height values for the length of the levee if available.
No Data Year Levee Constructed Year levee system was fully completed as a flood reduction project.
1964 Summary
General text description of the levee system with a summary of why the levee is there, and the benefits it provides.
The Jackson Project includes 12 levee segments along the Snake and Gros Ventre (pronounced “Grow Vont”) Rivers in Jackson Hole, which is in Teton County, Wyoming. NWW is responsible for O&M of the Jackson Project in partnership with Teton County. The County provides the initial funds for annual O&M. Nine of the 12 segments consist of non-Federal levees that were originally constructed by the County and the Corps. The JY Ranch to Public Levees is one of the federally constructed segments. It is continuous along 13.4 miles of the right bank on the Snake River. The levees are earth embankments with a crest width of 15 feet, landside slopes of approximately 1.5H:1V, riverside slopes of 4H:1V between crown and top of revetment, and riprap revetment slope of 2H:1V. Landside height is on the order of 10 feet.
Performance & Condition
General text description of the historical and anticipated performance of the levee, the people and property benefitting from the levee and who may be at risk of flooding, and actions to address areas of concern.
PLEASE NOTE: The following Risk Characterization is a description of risk associated with this levee system. It is currently undergoing review and may be updated in the future.
The LSOG considers the risk characterization for the JY to Public levee segment (LST ID 2529) to be overall Moderate (LSAC 3) with the Prior to Overtopping scenario (Moderate, LSAC 3), contributing more to the overall risk versus the Overtopping scenario (Low, LSAC 4). The levee has required flood fighting in past to prevent a breach, but repairs had been made to address many of the issues. For an event to the top of the levee, erosion is the performance factor of highest concern due to the composition of embankment materials (poorly graded sand with cobbles) in combination with high velocities and braided stream. In the event of a breach, however, sheet flow is expected because the levee does not tie into high ground at the downstream end. Therefore, loss of life is expected to be low while economic damages are expected to be high. The risk associated with overtopping is low (5000 ACE), because the levee system across the river would overtop prior to this levee overtopping.
Flooding Hazard
Historic Loading by Percentage of Height
Representative loading associated with historical flood information as a percentage of the levee height or overtopping.
Representative loading associated with historical flood information as a percentage of the levee height or overtopping.
0 Occurrences 0 Occurrences 1 Occurrences 27 Occurrences