Houston, TEXAS

The Addicks and Barker Dams are part of the intricate flood control system near downtown Houston, TX. During rehabilitation, dewatering was required for stabilization and integrity of the excavations and of the dam itself. 


The project required control of seepage through the soils below the dams for the construction of new outlet structures. This was required for stabilization of the excavations and of the dam itself. The geology at the site consists of layered sands, silts, and clays which greatly increase the chances of encountering perched/trapped groundwater. In addition to the normal challenges in a project of this nature, Hurricane Harvey, currently the tropical storm responsible for the most rain ever recorded from a storm event in the United States, occurred during the construction. 


Due to the complexity of the project, Griffin Dewatering’s licensed professional engineering team performed a comprehensive review of the available geotechnical information and joined the Granite team for test pit digs prior to each excavation to tailor the dewatering approach to the actual conditions encountered. Griffin has installed multiple wellpoint systems at the Addicks and Barker dams to allow for the safe, stable excavation of the new outlet structures and channels. All systems were installed by drilling, an acceptable installation method within the very close proximity to the dams.


Griffin’s significant experience in the Houston area, as well as our extensive experience in high-risk dam and levee excavations, was critical to determining the safest, most cost-effective project approach. Due to the highly variable geology at the sites, it was imperative to verify actual site conditions with the Granite team and the USACE so that the most appropriate dewatering method could be utilized. This approach led to dewatering by a combination of wellpoints and sumping and resulted in a truly collaborative effort between the USACE, Granite Construction, and Griffin to find the safest, most cost-effective method for completing the work.