Hanna Lagoon (Cell 1 & 2) Reservoir Report
Nearby: Stephenson Dana Meadows
Last Updated: December 5, 2025
Hanna Lagoon (Cell 1 & 2) is a water resource located in Carbon County, Wyoming, with a primary purpose designated as 'Other'.
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Summary
Constructed in 1988, this Earth-type dam stands at 8 feet high and spans a length of 3900 feet, with a maximum storage capacity of 61 acre-feet. The lagoon is regulated by the State of Wyoming and is subject to regular inspections, with the last assessment conducted in July 2017 revealing a fair condition. Despite its low hazard potential, a high risk assessment has been assigned to Hanna Lagoon, indicating potential vulnerabilities that require attention.
The dam's location within the drainage of Big Ditch Creek ensures its significance in managing water resources and climate impacts in the region. The structure, designed by Paul McCarthy, features a stone core and a soil foundation, with two controlled outlet gates for water release. The absence of a spillway suggests a unique design that requires careful monitoring and maintenance to uphold safety standards. As a Local Government-owned facility, Hanna Lagoon plays a crucial role in water management and flood control efforts, highlighting the importance of maintaining its infrastructure for sustainable water resource utilization.
With its strategic positioning and critical role in water management, Hanna Lagoon serves as a vital asset for Carbon County and Wyoming. The lagoon's fair condition assessment, coupled with a high-risk designation, underscores the need for proactive risk management measures to ensure its long-term functionality and safety. By staying vigilant in monitoring the dam's structural integrity and implementing necessary maintenance and emergency preparedness measures, stakeholders can safeguard this essential water resource against potential climate-related challenges and contribute to the resilience of the surrounding ecosystem.
Year Completed |
1988 |
Dam Length |
3900 |
Dam Height |
8 |
River Or Stream |
DRAINAGE OF BIG DITCH CREEK |
Primary Dam Type |
Earth |
Surface Area |
21 |
Hydraulic Height |
5 |
Nid Storage |
61 |
Structural Height |
10 |
Outlet Gates |
Other Controlled - 2 |
Hazard Potential |
Low |
Foundations |
Soil |
Nid Height |
10 |
Seasonal Comparison
Weather Forecast
Nearby Streamflow Levels
Dam Data Reference
Condition Assessment
SatisfactoryNo existing or potential dam safety deficiencies are recognized. Acceptable performance is expected under all loading conditions (static, hydrologic, seismic) in accordance with the minimum applicable state or federal regulatory criteria or tolerable risk guidelines.
Fair
No existing dam safety deficiencies are recognized for normal operating conditions. Rare or extreme hydrologic and/or seismic events may result in a dam safety deficiency. Risk may be in the range to take further action. Note: Rare or extreme event is defined by the regulatory agency based on their minimum
Poor A dam safety deficiency is recognized for normal operating conditions which may realistically occur. Remedial action is necessary. POOR may also be used when uncertainties exist as to critical analysis parameters which identify a potential dam safety deficiency. Investigations and studies are necessary.
Unsatisfactory
A dam safety deficiency is recognized that requires immediate or emergency remedial action for problem resolution.
Not Rated
The dam has not been inspected, is not under state or federal jurisdiction, or has been inspected but, for whatever reason, has not been rated.
Not Available
Dams for which the condition assessment is restricted to approved government users.
Hazard Potential Classification
HighDams assigned the high hazard potential classification are those where failure or mis-operation will probably cause loss of human life.
Significant
Dams assigned the significant hazard potential classification are those dams where failure or mis-operation results in no probable loss of human life but can cause economic loss, environment damage, disruption of lifeline facilities, or impact other concerns. Significant hazard potential classification dams are often located in predominantly rural or agricultural areas but could be in areas with population and significant infrastructure.
Low
Dams assigned the low hazard potential classification are those where failure or mis-operation results in no probable loss of human life and low economic and/or environmental losses. Losses are principally limited to the owner's property.
Undetermined
Dams for which a downstream hazard potential has not been designated or is not provided.
Not Available
Dams for which the downstream hazard potential is restricted to approved government users.
Hanna Lagoon (Cell 1 & 2)