Soulajule Dam Reservoir Report

Last Updated: December 5, 2025

Soulajule Dam is a small earthen dam located in Marin County, California, that was constructed in 1964.


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Summary

It is situated on the San Geronimo Creek, a tributary of Lagunitas Creek, which flows into Tomales Bay. The dam provides water for agricultural purposes and is operated by the Marin Municipal Water District. The hydrology of the area is influenced by both surface flow and snowpack, with the dam playing a role in regulating water flow during both wet and dry seasons. The area surrounding the dam is used for agriculture, including dairy farms and vineyards, and is also popular for recreational activities such as hiking and fishing. The dam and surrounding area are managed by the Marin Municipal Water District and the Marin County Parks department.

Reservoir Details

Storage 24hr Change -3.85%
Percent of Normal 186%
Minimum 830.0 acre-ft
2021-10-20
Maximum 10,572.0 acre-ft
2023-01-08
Average 4,297 acre-ft
Nid_Height 122
Hydraulic_Height 110
Drainage_Area 18.7
Year_Completed 1979
Dam_Height 122
Hazard_Potential High
Primary_Dam_Type Earth
River_Or_Stream Arroyo Sausal
Surface_Area 310
Nid_Storage 10700
Dam_Length 700
       
Seasonal Comparison
Storage Levels
Pool Elevation Levels
Top Conserv Storage Levels
Inflow Levels

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.