Giffin #2 (Upper) Reservoir Report

Last Updated: December 5, 2025

Giffin #2 (Upper) is a privately owned earth dam located in Weld County, Colorado, along the Lone Tree Creek.


°F

°F

mph

Wind

%

Humidity

Summary

Built in 1952 for irrigation purposes, this dam stands at a height of 21 feet and has a storage capacity of 155 acre-feet. With a normal storage level of 91 acre-feet, the dam covers a surface area of 15 acres and serves a drainage area of 56 square miles.

Despite its low hazard potential and satisfactory condition assessment, Giffin #2 (Upper) is subject to state regulation, permitting, inspection, and enforcement by the Colorado Division of Water Resources. The dam features an uncontrolled spillway with a width of 187 feet, capable of discharging up to 4590 cubic feet per second in case of overflow. The last inspection of the dam was conducted in April 2016, with a moderate risk assessment rating of 3.

Located in the city of Nunn, Colorado, Giffin #2 (Upper) plays a crucial role in the local irrigation system, providing water for agricultural activities in the region. As a key infrastructure for water resource management, this dam represents a significant aspect of Colorado's water conservation and utilization efforts. Enthusiasts of water resources and climate will appreciate the engineering details and operational significance of Giffin #2 (Upper) in sustaining the water needs of the surrounding community.

Year Completed

1952

Dam Length

565

Dam Height

21

River Or Stream

LONE TREE CREEK

Primary Dam Type

Earth

Surface Area

15

Hydraulic Height

21

Drainage Area

56

Nid Storage

155

Structural Height

21

Hazard Potential

Low

Nid Height

21
       
Seasonal Comparison

Weather Forecast

View more

Nearby Streamflow Levels

Giffin #2 (Upper)CROW CREEK AT 19TH STREET Preview Crow Creek At 19th Street
3.20cfs
3cfs
Giffin #2 (Upper)CACHE LA POUDRE RIVER AT FORT COLLINS Preview Cache La Poudre River At Fort Collins
28.8cfs
29cfs
Giffin #2 (Upper)CACHE LA POUDRE R AB BOXELDER C Preview Cache La Poudre R Ab Boxelder C
4.61cfs
5cfs
Giffin #2 (Upper)NORTH FORK CACHE LA POUDRE R. AT LIVERMORE Preview North Fork Cache La Poudre R. At Livermore
4.22cfs
4cfs
Giffin #2 (Upper)CACHE LA POUDRE R A MO OF CN Preview Cache La Poudre R A Mo Of Cn
0.00cfs
0cfs
Giffin #2 (Upper)N FRK CACHE LA POUDRE R BLW HALLIGAN RES NR V DAL Preview N Frk Cache La Poudre R Blw Halligan Res Nr V Dal
0.25cfs
0cfs

Dam Data Reference

Condition Assessment

Satisfactory
No 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

High
Dams 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.
View more

Nearby Reservoirs