Warm Springs (Lake Sonoma) Reservoir Report

Last Updated: January 2, 2026

Warm Springs is a popular recreation area located in Lake Sonoma, California.


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Summary

The area is rich in history, as it was once a popular destination for indigenous tribes who used the hot springs for medicinal purposes. The hydrology of the area is supported by a combination of surface flow and snowpack providers, including the Russian River watershed and nearby mountain ranges. The Warm Springs area is used for both agricultural and recreational purposes, including grape and olive farming, camping, hiking, and fishing. The lake is also a popular spot for boating and swimming during the summer months. Despite its popularity, efforts have been made to protect the area's fragile ecosystem and promote sustainable land use practices.

Reservoir Details

Storage 24hr Change -0.11%
Percent of Normal 121%
Minimum 96,310.0 acre-ft
2022-12-09
Maximum 325,270.0 acre-ft
2017-01-23
Average 205,369 acre-ft
Nid_Height 356
Hydraulic_Height 313
Drainage_Area 130
Year_Completed 1983
Dam_Height 319
Structural_Height 356
River_Or_Stream DRY CREEK
Primary_Dam_Type Earth
Foundations Rock, Soil
Surface_Area 2600
Hazard_Potential High
Outlet_Gates Slide (sluice gate) - 2
Nid_Storage 449000
Dam_Length 3000
       
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.