Hooper No. 1 Reservoir Report

Last Updated: December 5, 2025

Hooper No.


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Summary

1 is a privately owned earth dam located in Hopland, Mendocino County, California, along the Tr Mcdowell Creek. The dam, with a height of 25 feet and a hydraulic height of 15.1 feet, was primarily built for irrigation purposes, providing a storage capacity of 200 acre-feet. Despite its fair condition assessment as of September 2017, the dam is classified as having a significant hazard potential, highlighting the importance of regular inspections and maintenance to ensure its safety and functionality.

Managed by the California Department of Water Resources (DWR) under the Safety of Dams program, Hooper No. 1 is subject to state regulations, permitting, inspection, and enforcement. The last inspection took place in January 2020, with a frequency of one inspection per year. The dam's condition assessment indicated its fair state, but with its significant hazard potential, it is crucial to have emergency action plans in place to mitigate risks and ensure the safety of downstream communities in case of a potential failure.

With its location in a region prone to climate variability and extreme weather events, the maintenance and monitoring of Hooper No. 1 are critical to safeguard the surrounding area from potential flooding and water resource disruptions. As water resource and climate enthusiasts, understanding the significance of dams like Hooper No. 1 in managing water supply for irrigation purposes underscores the importance of effective dam management practices to ensure both water security and community safety in the face of changing climatic conditions.

Dam Length

690

Dam Height

25

River Or Stream

Tr Mcdowell Creek

Primary Dam Type

Earth

Surface Area

16

Hydraulic Height

15.1

Nid Storage

200

Hazard Potential

Significant

Nid Height

25
       
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.