Tmpa Gibbons Creek Mine Dam 5a Reservoir Report

Last Updated: December 5, 2025

Tmpa Gibbons Creek Mine Dam 5a in Grimes, Texas, is a vital water resource structure regulated by the Texas Commission on Environmental Quality (TCEQ).


°F

°F

mph

Wind

%

Humidity

Summary

Completed in 1982, this earth dam stands at a height of 26 feet and spans a length of 4200 feet, serving as a key component in managing water flow along Dry Creek. With a maximum storage capacity of 969 acre-feet and a normal storage level of 204 acre-feet, the dam plays a crucial role in flood control and water supply management in the region.

Despite being uncontrolled, the spillway of Tmpa Gibbons Creek Mine Dam 5a is designed with a width of 300 feet to handle a maximum discharge of 24,308 cubic feet per second. The dam's hazard potential is deemed not available, with a moderate risk assessment rating of 3. While the structure's condition is not rated, it is subject to regular state inspections and enforcement measures to ensure its reliability and safety. The dam's emergency action plan status, risk management measures, and inundation maps readiness are currently undisclosed.

Owned by the local government and designed by Morrison Knudsen, Tmpa Gibbons Creek Mine Dam 5a is a critical infrastructure supporting various purposes beyond flood control, reflecting its significance in water resource management. With its strategic location, sizeable storage capacity, and regulated operation, this dam serves as a key asset in safeguarding the water supply and mitigating potential hazards in the region. Enthusiasts of water resources and climate resilience would find this structure a compelling case study in sustainable dam management practices.

Year Completed

1982

Dam Length

4200

Dam Height

26

River Or Stream

DRY CREEK

Primary Dam Type

Earth

Surface Area

38.2

Hydraulic Height

26

Drainage Area

0.77

Nid Storage

969

Structural Height

26

Outlet Gates

Uncontrolled - 4

Hazard Potential

Not Available

Foundations

Unlisted/Unknown

Nid Height

26
       
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.