Upper San Marcos River Ws Scs Site 3

Upper San Marcos River Ws Scs Site 3 is an earth dam located in Hays County, Texas, built in 1991. It carries a High hazard potential classification and has a satisfactory condition assessment.

About Upper San Marcos River Ws Scs Site 3

The primary purpose of Upper San Marcos River Ws Scs Site 3 is flood risk reduction. The dam is designed to control downstream flooding by temporarily storing excess water during storms and releasing it at a controlled rate. The dam is owned by City Of San Marcos;hays County;hays County Swcd;upper San Marcos Ws Recl Fcd (local government). It impounds the Sink Creek near San Marcos.

The dam stands 60 feet tall and stretches 988 feet across, creates a reservoir covering 20 acres, has a maximum storage capacity of 4,323 acre-feet, and collects water from a drainage area of 5 square miles. Completed in 1991, the structure is 35 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 10/13/2020.

At 60 feet, this dam is taller than 95% 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 Texas 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

StateTexas
CountyHays
Nearest CitySan Marcos
River/StreamSink Creek
Coordinates29.90689, -97.94536

Physical Characteristics

Dam TypeEarth
NID Height60 ft
Dam Height60 ft
Dam Length988 ft
Year Completed1991 (35 years old)

Storage & Hydraulics

NID Storage4,323 acre-ft
Max Storage4,323 acre-ft
Normal Storage127 acre-ft
Surface Area20 acres
Drainage Area5 sq mi
Max Discharge79,912 cfs
Spillway TypeUncontrolled

Ownership & Safety

PurposeFlood Risk Reduction
OwnerCITY OF SAN MARCOS;HAYS COUNTY;HAYS COUNTY SWCD;UPPER SAN MARCOS WS RECL FCD
Owner TypeLocal Government
Hazard ClassificationHigh
Condition AssessmentSatisfactory
Last Inspection10/13/2020
Emergency Action PlanYes

Identifiers

NID IDTX06432
Federal IDTX06432
More InfoState Dam Safety Program

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