Nissen #2 Reservoir Report

Last Updated: December 5, 2025

Nissen #2 is a privately owned earth dam located in Broomfield, Colorado, with a primary purpose of irrigation.


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Summary

Completed in 1974, this dam stands at a height of 9 feet and has a length of 2300 feet, providing a storage capacity of 291 acre-feet. Situated on Big Dry Creek-OS, this dam has a spillway width of 160 feet and a maximum discharge of 1005 cubic feet per second, making it a crucial structure for managing water resources in the area.

With a high hazard potential but a satisfactory condition assessment as of December 2020, Nissen #2 is regularly inspected by the state regulatory agency to ensure its safety and compliance with regulations. The dam's risk assessment categorizes it as moderate, prompting the need for ongoing risk management measures. The presence of this dam plays a vital role in supporting irrigation activities in the region, highlighting the importance of water infrastructure for agricultural sustainability and climate resilience in Colorado.

As water resource and climate enthusiasts, understanding the significance of structures like Nissen #2 is crucial for ensuring the sustainable management of water systems in the face of changing environmental conditions. By monitoring and maintaining dams like Nissen #2, stakeholders can work towards enhancing water security and resilience in the region, ultimately contributing to the long-term sustainability of Colorado's water resources in a changing climate.

Year Completed

1974

Dam Length

2300

Dam Height

6

River Or Stream

BIG DRY CREEK-OS

Primary Dam Type

Earth

Surface Area

29

Hydraulic Height

6

Nid Storage

291

Structural Height

9

Hazard Potential

High

Nid Height

9
       
Seasonal Comparison

Weather Forecast

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.