Fairport Reservoir Report

Last Updated: December 5, 2025

Fairport, also known as the Robert Benson Reservoir, is a key water resource in Larimer, Colorado, primarily used for irrigation purposes.


°F

°F

mph

Wind

%

Humidity

Summary

This local government-owned Earth dam was completed in 1882 and has a height of 12 feet, with a storage capacity of 390 acre-feet. Located on the Big Thompson River, Fairport plays a crucial role in water management and serves as a vital resource for the surrounding community in Ft. Collins.

With a spillway width of 176 feet and a maximum discharge of 3945 cubic feet per second, Fairport has been deemed to have a significant hazard potential. Despite this, the dam's condition was assessed as satisfactory during its last inspection in July 2020. The risk assessment for the dam is moderate (3), indicating a need for ongoing monitoring and risk management measures to ensure the safety and stability of the structure in the face of potential climate-related challenges and extreme weather events.

Fairport's historical significance and functional importance make it a focal point for water resource and climate enthusiasts in the region. As a regulated and permitted structure under the oversight of the Colorado Division of Water Resources, the dam's operation and maintenance are critical for sustaining water supply and mitigating risks associated with its use. With its location on the Big Thompson River and its role in irrigation, Fairport serves as a reminder of the complex interplay between water resources, infrastructure, and climate resilience in the face of changing environmental conditions.

Year Completed

1882

Dam Length

640

Dam Height

12

River Or Stream

BIG THOMPSON RIVER-OS

Primary Dam Type

Earth

Surface Area

52

Hydraulic Height

8

Nid Storage

390

Structural Height

13

Hazard Potential

Significant

Nid Height

13
       
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.