Ewing

Ewing is an earth dam located in Trinity County, California, built in 1972. It carries a High hazard potential classification and has a satisfactory condition assessment.

About Ewing

The primary purpose of Ewing 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 Trinity County Waterworks District 1 (local government). It impounds the Ewing Gulch near Hayfork.

The dam stands 63 feet tall and stretches 550 feet across, creates a reservoir covering 43 acres, has a maximum storage capacity of 887 acre-feet, and collects water from a drainage area of 0 square miles. Completed in 1972, 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 05/06/2025.

At 63 feet, this dam is taller than 96% of all dams in the United States.

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.

High HazardSatisfactory ConditionEmergency Action Plan: Yes

Location

StateCalifornia
CountyTrinity
Nearest CityHayfork
River/StreamEwing Gulch
Coordinates40.56290, -123.16730

Physical Characteristics

Dam TypeEarth
NID Height63 ft
Dam Height63 ft
Dam Length550 ft
Year Completed1972 (54 years old)

Storage & Hydraulics

NID Storage887 acre-ft
Max Storage887 acre-ft
Surface Area43 acres
Drainage Area0 sq mi

Ownership & Safety

PurposeWater Supply
OwnerTrinity County Waterworks District 1
Owner TypeLocal Government
Hazard ClassificationHigh
Condition AssessmentSatisfactory
Last Inspection05/06/2025
Emergency Action PlanYes

Identifiers

NID IDCA00903
Federal IDCA00903
More InfoState Dam Safety Program