Old Lampasas Dam Modernization

July 2025 Construction Update

Crews have begun installation of the Old Lampasas Dam Modernization project's primary spillway pipe and cradle. Construction of the auxiliary spillway continues as well, with underdrain* construction currently underway.

Completed Tasks:

Two-thirds of the primary spillway's outlet pipe has been installed
Approximately 140,000 cubic yards of rock material in total were transported for reuse in various City facilities and projects, including:
- 13,400 cubic yards to the Transportation and Public Works Department
- 1,100 cubic yards to the Parks and Recreation Department
- 400 cubic yards to the Watershed Protection Department

Current Work:

Primary spillway pipe installation
Auxiliary spillway underdrain* construction
*A pipe that controls the flow of water through the dam

Upcoming Work:

Construction of the principal inlet structure base

Primary spillway construction

Project Background

Built in 1984, the Old Lampasas Dam is a high-risk dam that is in poor condition and was significantly damaged during Tropical Storm Hermine in 2010. This project will repair the dam, bring it into compliance with Texas Commission on Environmental Quality (TCEQ) safety regulations, reduce flood risks in the neighborhood, and improve water quality in Bull Creek. Construction for the Old Lampasas Dam Modernization project began in October 2024 and is anticipated to reach substantial completion by spring 2026, weather permitting.

Auxiliary spillway construction

Reminders and Timeline

The construction site is for authorized personnel only
City of Austin permitted construction hours are:
- Monday – Friday, 7 a.m. – 7 p.m.
- Saturday, 8 a.m. – 7 p.m.
The project team will notify neighborhoods in advance of any weekend work

For more information, email CapitalDelivery@AustinTexas.gov.
Visit the Old Lampasas Dam Modernization webpage for additional project details.

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