The project consists of the replacement of two aging spillway crest gates, and retrofitting 25 additional bays on the dam with the installation of a new dewatering system using new stop logs. A new gantry crane will also be added that will help in moving the stop logs to any section of the dam.
The Waller Creek corridor in downtown Austin is part of a 100-year floodplain and, by the project’s start date in July 2012, was in need of a comprehensive flood relief plan. The City of Austin awarded Zachry a contract to construct a flood outlet structure that provides immediate storm water relief and reintegrate a vibrant new space into the heart of the Texas Capital.
In addition to providing a cost-effective flood control system for lower Waller Creek, the project reduces flood risk by narrowing the floodplain, enhances water quality, mitigates creek-bed erosion, complements the surrounding cityscape and, ultimately, provides increased economic activity by opening up nearly 28 acres of flood-prone land to development.
In addition to providing a cost-effective flood control system for lower Waller Creek, the project will reduce flood risk by narrowing the floodplain, enhance water quality, mitigate creek-bed erosion, complement the surrounding cityscape and, ultimately, provide increased economic activity by opening up some 28 acres of flood-prone land to development.
The new outlet structure also entails the construction of a cofferdam -a temporary dry work area used during the project) a maintenance access road and an adjacent lagoon measuring 150 feet wide and 50 feet deep.
Zachry seamlessly incorporated all design and aesthetic considerations with virtually no disruption to the overall schedule and budget.
With the completion of the Mission Reach Ecosystem Restoration and Recreation Project in October 2014, the San Antonio River Authority gained a new piece of history adding to San Antonio’s storied culture and quality of life.
The multi-year, eight-mile project transformed the south end of the San Antonio River into a woodland ecosystem with a myriad of recreational opportunities. This unique project, managed by the San Antonio River Authority (SARA) and executed by Zachry, is the product of a long-standing business relationship between the two entities.
The City of San Antonio, Bexar County, SARA, the San Antonio River Foundation, the San Antonio River Improvements Project and the U.S. Army Corps of Engineers funded combined projects valued at more than $250 million.
The Mission Reach project created pool-riffle-run sequences (to aid the river flow), reintroduced native plants, enhanced the aquatic habitat and reconnected Missions Concepción and Espada. It also created new recreational attractions, including fishing piers, canoe/kayak chutes, and hike and bike trails.
The project will rebuild and replace all three 93-year-old spill gates on Lake Dunlap Dam. This dam is located on the Guadalupe River between Seguin and New Braunfels, TX in Guadalupe County. In May 2019, one gate collapsed due to aging steel supports. This failure drained the lake by 12 feet, halted power production, and plummeted local property values. To get the two-year project going, Zachry built a trestle in front of the existing dam, allowing crane access to install a temporary coffer dam and reconstruct the dam with new hydraulic gates.
Work consists of a 15-foot widening of the existing dam structure to include new gates and a new overhead gantry crane for future dam maintenance. A new concrete 220-footwide emergency spillway will be added to the east side of the dam. New armoring consisting of both concrete and rock riprap will also be added along the existing 1,500-foot-long core wall extending on both sides of the dam.
The San Antonio Water System (SAWS) desalination project, a Zachry-led joint venture, transforms brackish water into millions of gallons of drinkable water. SAWS and the City of San Antonio (CoSA) worked together to find an alternative source of water for San Antonio. The solution was to drill deeper, going up to 1,720 feet for the production supply wells and over 5,000 feet deep for the disposal wells.
This project is Phase I of the solution which included a 60,000-square-foot water treatment plant facility located at the previous SAWS Twin Oaks Aquifer Storage and Recovery site (3,000 acres). The facility is now called H2Oaks and produces up to 12 million gallons of treated water per day through a reverse osmosis process in which salts and minerals are removed or desalination. The treatment plant involved a complicated process of mechanical, electrical and supervisory control and data acquisition (SCADA) – basically the brains of the plant controls systems; some of this equipment required many months lead times for manufacturing.
The project also included drilling four production wells and one injection well, the fit out of 12 production and two injection well sites, and installing over 12 miles of high density polyethylene (HDPE) – a thick walled piping that is somewhat flexible and “fused” (welded) together at the joints, conveyance pipeline and access roads to the remote well sites. Zachry also provided start-up, commissioning and acceptance testing.
SAWS now uses H2Oaks as a public tour destination, with bus parking lanes, large observation areas, a conference room and a laboratory for college-level research projects. Phases II and III are expected to produce an additional 12 and 6 MGD, respectively, bringing the total capacity to 30 MGD by 2026 — the largest in Texas and the largest inland desalination plant in the country.
Phases II and III are expected to produce an additional 12 and 6 MGD, respectively, bringing the program’s total capacity to 30 MGD by 2026 — the largest in Texas and the largest inland desalination plant in the country.
This three-phase segment doubled the length of the existing River Walk and extends the distinctive San Antonio experience to an undeveloped section of the river north of downtown. Construction of this segment stabilized the river channel and extended navigation by river barge through the addition of a lock and dam.
Zachry provided major excavation services, concrete work, bulkhead erection, retaining walls, and a lock and dam system on an active river. This required careful water management through wellpoint dewatering, surface unwatering, river flow surface diversion, river flow bypass pumping diversion and cofferdams.
The architectural scope included public restrooms, a street to the river barge unloading/loading facility, visitor overlook facilities at numerous locations, and complete lighting and signage systems.
Upon the discovery of historic rock dam remains, the Museum Reach project called for an extensive redesign — without impacting the overall schedule and budget.
The San Antonio River Authority (SARA) was in charge of the overall management of the San Antonio River Improvements Project (SARIP). The development and coordination of SARIP was the result of cooperation among the City of San Antonio, Bexar County, SARA, the USACE, the San Antonio River Oversight Committee and the San Antonio River Foundation. SARIP represented the best of inter-governmental and public–private ownership.