Cedar Rapids Milldam Iel&P Reservoir Report

Last Updated: December 5, 2025

Cedar Rapids Milldam Iel&P, located on the Cedar River in Iowa, serves as a critical water supply infrastructure for the city of Cedar Rapids.


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Summary

The dam, constructed in 1967 by HOWARD R GREEN CO, is a gravity type structure with a height of 8 feet and a length of 685 feet. It has a storage capacity of 1440 acre-feet, with a normal storage level of 840 acre-feet, supporting a surface area of 2380 acres and a drainage area of 6726 acres.

Despite being rated as having a low hazard potential and not assessed for condition, the Cedar Rapids Milldam Iel&P plays a crucial role in securing the water supply for the city. The dam is regulated by the Iowa Department of Natural Resources and undergoes state inspection, permitting, and enforcement to ensure its safe operation. The risk assessment for the dam is moderate, highlighting the importance of implementing effective risk management measures to safeguard the surrounding area.

As an integral part of the water supply infrastructure in Cedar Rapids, the Cedar Rapids Milldam Iel&P showcases the intersection of water resource management and climate resilience. With its controlled spillway and state-regulated operation, the dam contributes to the city's water security while also posing a moderate risk that necessitates ongoing monitoring and management. As climate change continues to impact water resources, maintaining and enhancing the resilience of structures like Cedar Rapids Milldam Iel&P is crucial for ensuring a sustainable and secure water supply for the community.

Year Completed

1967

Dam Length

685

Dam Height

8

River Or Stream

CEDAR RIVER

Primary Dam Type

Gravity

Surface Area

2380

Drainage Area

6726

Nid Storage

1440

Hazard Potential

Low

Foundations

Soil

Nid Height

8
       
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.