Dina Bob Lake

Dina Bob Lake is an earth dam located in Sonoma County, California, built in 1955. It carries a Significant hazard potential classification and has a satisfactory condition assessment.

About Dina Bob Lake

The primary purpose of Dina Bob Lake is water supply. The dam stores water for municipal, industrial, or agricultural use, helping ensure a reliable supply for the surrounding area. The dam is owned by Robert D. Ogg (private). It impounds the Tr Franz Cr.

The dam stands 33 feet tall and stretches 635 feet across, creates a reservoir covering 14 acres, has a maximum storage capacity of 139 acre-feet, and collects water from a drainage area of 0 square miles. Completed in 1955, the structure is well into its service life at over 50 years old.

This dam has a significant hazard potential classification, meaning that a failure could cause significant economic damage — flooding roads, bridges, or property downstream — but is not expected to result in loss of life. Its condition is rated satisfactory, indicating no existing or potential dam safety deficiencies are recognized. An emergency action plan is in place for this dam. The most recent inspection on record was 08/14/2025.

At 33 feet, this dam is taller than 78% of dams nationwide.

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Significant HazardSatisfactory ConditionEmergency Action Plan: Yes

Location

StateCalifornia
CountySonoma
River/StreamTr Franz Cr
Coordinates38.61660, -122.68910

Physical Characteristics

Dam TypeEarth
NID Height33 ft
Dam Height33 ft
Dam Length635 ft
Year Completed1955 (71 years old)

Storage & Hydraulics

NID Storage139 acre-ft
Max Storage139 acre-ft
Surface Area14 acres
Drainage Area0 sq mi

Ownership & Safety

PurposeWater Supply
OwnerRobert D. Ogg
Owner TypePrivate
Hazard ClassificationSignificant
Condition AssessmentSatisfactory
Last Inspection08/14/2025
Emergency Action PlanYes

Identifiers

NID IDCA00991
Federal IDCA00991
More InfoState Dam Safety Program

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