Blue Grass Lake Dam Reservoir Report

Last Updated: December 13, 2025

Blue Grass Lake Dam, located in Scott County, Iowa, is a local government-owned structure built in 1974 for recreational purposes.


°F

°F

mph

Wind

%

Humidity

Summary

The dam stands at a height of 28 feet and spans 850 feet in length, creating a reservoir with a normal storage capacity of 93 acre-feet and a maximum storage of 490 acre-feet. Situated on Black Hawk Creek, the dam is regulated by the Iowa Department of Natural Resources and undergoes regular inspections to ensure its satisfactory condition.

With a significant hazard potential and a moderate risk assessment rating, the Blue Grass Lake Dam is considered a crucial structure in the region. Despite its uncontrolled spillway type, the dam has not experienced any major incidents and continues to provide recreational opportunities to the community. The dam's condition assessment in June 2020 deemed it satisfactory, highlighting the efforts taken to maintain its safety and integrity. Enthusiasts of water resources and climate will appreciate the importance of this dam in managing water flow and providing a source of enjoyment for visitors to the I-280 Lake area.

Year Completed

1974

Dam Length

850

Dam Height

28

River Or Stream

BLACK HAWK CREEK

Primary Dam Type

Earth

Surface Area

13.8

Drainage Area

0.8

Nid Storage

490

Hazard Potential

Significant

Foundations

Soil

Nid Height

28
       
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.