Rinconada Reservoir

Rinconada Reservoir is an earth dam located in Santa Clara County, California, built in 1969. It carries a High hazard potential classification and has a satisfactory condition assessment.

Hazard potentialHighFailure would probably cost lives
ConditionSatisfactoryBest of 4 ratings
Emergency action planOn file
Last inspection11/18/2025
Height40 ft
Built196957 years ago

Dam profile

NID height · 40 ft
40 FT TWO-STORY HOUSEMEDIAN U.S. DAM · 24 FT

40 ft tall and 240 ft long, taller than 86% of U.S. dams with a recorded height. Height is drawn to scale against a two-story house, about 25 ft; the profile is a generic embankment section and the water level is illustrative.

About Rinconada Reservoir

The primary purpose of Rinconada Reservoir 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 Santa Clara Valley Water District (public utility). It impounds the Offstream near San Jose.

The dam stands 40 feet tall and stretches 240 feet across, creates a reservoir covering 3 acres, and has a maximum storage capacity of 46 acre-feet. Completed in 1969, the structure is well into its service life at over 50 years old.

This dam carries a high hazard potential classification, which means that a failure or uncontrolled release of water would likely cause loss of human life. This classification reflects the consequences of failure, not the likelihood — it indicates that people live or work in the area downstream. 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 11/18/2025.

At 40 feet, this dam is taller than 86% of dams nationwide.

Living Downstream

If you live or work downstream of this dam, consider taking these steps: learn your local evacuation routes, check whether your county emergency management office has a dam failure inundation map, and sign up for local emergency alerts. The California dam safety program can provide more specific information about emergency planning for this structure.

Search for dams near your address to see all dams in your area with hazard classifications and safety data.

Location

StateCalifornia
CountySanta Clara
Nearest CitySan Jose
River/StreamOffstream
Coordinates37.25590, -121.98590

Physical Characteristics

Dam TypeEarth
NID Height40 ft
Dam Height40 ft
Dam Length240 ft
Year Completed1969 (57 years old)

Storage & Hydraulics

NID Storage46 acre-ft
Max Storage46 acre-ft
Surface Area3 acres

Ownership & Safety

PurposeWater Supply
OwnerSanta Clara Valley Water District
Owner TypePublic Utility
Hazard ClassificationHigh
Condition AssessmentSatisfactory
Last Inspection11/18/2025
Emergency Action PlanYes

Identifiers

NID IDCA00295
Federal IDCA00295
More InfoState Dam Safety Program