Magoon No. 1 Reservoir Report
Nearby: Bast No. 1 Stock Carrico No. 1
Last Updated: March 4, 2026
Magoon No.
Summary
1 is a privately owned earth dam located in Niobrara, Wyoming, along the Young Woman Creek. Completed in 1959 for irrigation purposes, this structure stands at 25 feet high with a hydraulic height of 20 feet, spanning a length of 508 feet. With a storage capacity of 593 acre-feet, the dam serves as a vital resource for water management in the region, storing up to 358 acre-feet of water during normal conditions.
Despite its age, Magoon No. 1 is considered to have a low hazard potential and is in fair condition according to a recent assessment conducted in July 2020. With a moderate risk assessment rating of 3, the dam is inspected every five years to ensure its structural integrity and safety. Equipped with a slide gate for outlet control, the dam also features an uncontrolled spillway with a width of 50 feet, allowing for controlled water release during times of high flow.
Managed by the Wyoming State Engineer's Office, Magoon No. 1 plays a crucial role in supporting agricultural activities in the area, highlighting the importance of maintaining and monitoring this essential water resource for both irrigation and flood control purposes.
°F
°F
mph
Wind
%
Humidity
15-Day Weather Outlook
Year Completed |
1959 |
Dam Length |
508 |
Dam Height |
25 |
River Or Stream |
YOUNG WOMAN CREEK |
Primary Dam Type |
Earth |
Surface Area |
39 |
Hydraulic Height |
20 |
Nid Storage |
593 |
Structural Height |
25 |
Outlet Gates |
Slide (sluice gate) - 1 |
Hazard Potential |
Low |
Foundations |
Soil |
Nid Height |
25 |
Seasonal Comparison
5-Day Hourly Forecast Detail
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.
Magoon No. 1