Banning Lewis #1 Reservoir Report

Last Updated: December 5, 2025

Banning Lewis #1, located in Colorado Springs, Colorado, is a privately owned earth dam constructed in 1888 for flood risk reduction along the East Fork Sand Creek.


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Summary

With a height of 30 feet and a length of 750 feet, the dam has a storage capacity of 150 acre-feet and serves multiple purposes including fire protection, stock, or small fish pond, in addition to flood risk reduction. Despite its age, the dam has a low hazard potential and is currently not rated for its condition.

Although last inspected in 1998, with a scheduled inspection frequency of 6 years, Banning Lewis #1 is under state regulation with permitting, inspection, and enforcement processes in place. The dam has a maximum discharge rate of 2,645 cubic feet per second and a spillway width of 90 feet. While it presents a high risk due to its age and lack of recent assessments, the dam remains an essential structure for managing water resources and climate-related challenges in the region.

Water resource and climate enthusiasts will find Banning Lewis #1 a fascinating example of historic infrastructure designed to mitigate flood risks and support various water management purposes. As an integral component of the water system in El Paso County, this dam serves as a reminder of the ongoing need for monitoring and maintenance to ensure its continued effectiveness in protecting the surrounding community from potential hazards.

Year Completed

1888

Dam Length

750

Dam Height

30

River Or Stream

EAST FORK SAND CREEK

Primary Dam Type

Earth

Surface Area

10

Hydraulic Height

30

Drainage Area

3

Nid Storage

150

Structural Height

30

Hazard Potential

Low

Nid Height

30
       
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.