New Hogan Dam Reservoir Report

Last Updated: December 5, 2025

New Hogan Dam, located in California along the Calaveras River, serves as a crucial flood risk reduction structure that provides multiple benefits to the surrounding communities.


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Summary

Completed in 1963 by the US Army Corps of Engineers, this rockfill dam stands at a height of 210 feet and has a storage capacity of up to 348,598 acre-feet. While the dam has historically performed well in reducing the risk of flooding to downstream areas, a 2006 risk assessment highlighted potential concerns, such as the lack of spillway adequacy and the possibility of dam deformations during a major earthquake.

To manage these risks, USACE closely collaborates with local emergency managers, regularly updates emergency action plans, and conducts drills to enhance preparedness. The full-time staff at New Hogan Dam ensures regular maintenance and immediate inspections in case of any unusual events. By incorporating weather forecasts and monitoring localized flows, USACE can make informed decisions on dam operations to mitigate potential threats to downstream communities. While the scenarios of dam failure are considered extremely unlikely, the emergency action plan for New Hogan Dam is in place to lower the risk of life loss and protect the surrounding infrastructure from significant flooding impacts.

Year Completed

1963

Dam Length

1960

Dam Height

155

River Or Stream

CALAVERAS RIVER

Primary Dam Type

Rockfill

Surface Area

4400

Hydraulic Height

195

Drainage Area

363

Nid Storage

317100

Structural Height

210

Hazard Potential

High

Nid Height

210
       
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.