Giffin #1 (Lower) Reservoir Report
Nearby: Giffin #2 (Upper) Decker
Last Updated: December 5, 2025
Giffin #1 (Lower) is a privately-owned irrigation dam located on Lone Tree Creek in Weld County, Colorado.
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Summary
Built in 1948 by designer J.E. WHITTEN, this earth dam stands at 17 feet high and 575 feet long, with a storage capacity of 109 acre-feet. The dam serves the primary purpose of irrigation and is regulated by the Colorado Division of Water Resources.
With a low hazard potential and satisfactory condition assessment, Giffin #1 (Lower) poses a moderate risk factor according to the data. The dam has a spillway type of "Uncontrolled" and a maximum discharge rate of 8060 cubic feet per second. The last inspection was conducted in April 2016, with a scheduled inspection frequency of every 6 years.
Water resource and climate enthusiasts interested in the infrastructure of irrigation dams will find Giffin #1 (Lower) an intriguing case study. Located in the picturesque city of Nunn, this dam plays a crucial role in water management and agricultural activities in the region, highlighting the importance of responsible dam maintenance and regulation for sustainable water resource management in Colorado.
Year Completed |
1948 |
Dam Length |
575 |
Dam Height |
17 |
River Or Stream |
LONE TREE CREEK |
Primary Dam Type |
Earth |
Surface Area |
8 |
Hydraulic Height |
17 |
Drainage Area |
57 |
Nid Storage |
109 |
Structural Height |
17 |
Hazard Potential |
Low |
Nid Height |
17 |
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.
Giffin #1 (Lower)