Castle Rock Dam Reservoir Report

Last Updated: December 7, 2025

Castle Rock Dam, also known as Jacob or Roemmich Dam, is a privately owned structure located in North Dakota along the Cannonball River.


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Summary

Built in 1969 by the USDA NRCS, this earth dam stands at a height of 18 feet and has a length of 818 feet. The primary purpose of Castle Rock Dam is for recreation, offering a surface area of 14.2 acres and a normal storage capacity of 75.1 acre-feet.

Managed by the NDSWC, Castle Rock Dam is regulated, permitted, inspected, and enforced by the state of North Dakota. Despite being classified as having a low hazard potential, the dam underwent structural modifications in 1994. With a moderate risk assessment rating of 3, the dam's condition is currently not rated, and the last inspection took place in April 1982. Although the dam does not have outlet gates or associated locks, its spillway type is uncontrolled with a width of 100 feet.

For water resource and climate enthusiasts, Castle Rock Dam offers a fascinating case study in the management and regulation of a privately owned recreational dam in North Dakota. With its historical significance, ongoing risk assessments, and state oversight, this earth dam serves as a reminder of the importance of maintaining infrastructure for both human enjoyment and environmental protection along the Cannonball River.

Years Modified

1994 - Structural

Year Completed

1969

Dam Length

818

Dam Height

18

River Or Stream

CANNONBALL RIVER-TR

Primary Dam Type

Earth

Surface Area

14.2

Drainage Area

2.66

Nid Storage

184

Structural Height

8.7

Outlet Gates

None

Hazard Potential

Low

Foundations

Soil

Nid Height

18
       
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.