Atwell Dam Reservoir Report

Last Updated: December 8, 2025

Atwell Dam is a private dam located in Lucas, Iowa, near Lake Morris.


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Summary

Completed in 1997, the earth dam stands at 30 feet high and stretches 410 feet in length, with a storage capacity of 143 acre-feet. Its primary purpose is for fire protection, stock, or as a small fish pond. The dam is regulated by the Iowa Department of Natural Resources and undergoes regular inspections and enforcement to ensure its safety and compliance with state regulations.

Situated on TR- Little Whitebreast Creek, Atwell Dam poses a low hazard potential with a moderate risk assessment rating. The dam's spillway is of the uncontrolled type, and it has not been modified since its completion. Although the condition assessment is currently listed as "Not Rated," the dam's risk management measures are not specified. Despite its low hazard potential, the dam is equipped to handle emergencies, although details on emergency action plans and inundation mapping are not provided in the available data.

Water resource and climate enthusiasts may appreciate Atwell Dam for its role in providing essential fire protection and water storage in the area. With its location in a picturesque setting near Lake Morris, the dam serves as a vital resource for the community while also presenting opportunities for wildlife habitat and recreational activities. As a privately owned structure, Atwell Dam plays a significant role in water management and conservation efforts in Lucas County, Iowa, offering a glimpse into the intersection of human infrastructure with natural landscapes.

Year Completed

1997

Dam Length

410

Dam Height

30

River Or Stream

TR- LITTLE WHITEBREAST CREEK

Primary Dam Type

Earth

Surface Area

9.2

Drainage Area

0.3

Nid Storage

143

Hazard Potential

Low

Foundations

Soil

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.