Upper East Fk Laterals Ws Scs Site 5a Dam Reservoir Report

Last Updated: December 5, 2025

The Upper East Fk Laterals WS SCS Site 5a Dam, also known as Rainbow Lake, is a prominent earth dam located in Rockwall, Texas.


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Summary

Constructed in 1955 by the USDA NRCS, this dam serves multiple purposes including flood risk reduction, fire protection, stock management, and recreation. With a height of 39 feet and a length of 1934 feet, this dam has a normal storage capacity of 131 acre-feet and a maximum storage capacity of 890 acre-feet.

Owned by the local government and regulated by the TCEQ, the Upper East Fk Laterals WS SCS Site 5a Dam plays a crucial role in managing water resources in the area. The dam has a fair condition assessment as of April 2021 and is inspected every 5 years to ensure its structural integrity. In the event of an emergency, the dam has slide and uncontrolled gates for water release, with a spillway width of 109 feet.

With its strategic location on the Brockway Branch river, the Upper East Fk Laterals WS SCS Site 5a Dam is a key asset in the region's water management infrastructure. Enthusiasts of water resources and climate will appreciate the role that this dam plays in flood risk reduction and water storage, while also providing opportunities for recreation and fire protection in the area.

Year Completed

1955

Dam Length

1934

Dam Height

39

River Or Stream

BROCKWAY BRANCH

Primary Dam Type

Earth

Hydraulic Height

39

Drainage Area

1.33

Nid Storage

890

Structural Height

39

Outlet Gates

Slide (sluice gate) - 1, Uncontrolled - 2

Hazard Potential

Not Available

Foundations

Unlisted/Unknown

Nid Height

39
       
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.