--- title: Dam Construction | Underwater Construction on Dams description: Brennan divers know dams and are experts in underwater construction techniques such as underwater concrete placement, underwater welding, and more. image: https://www.jfbrennan.com/hubfs/Diver%20Photos%20-%202025%20Recent/2023%20Portadam%20Install%20-%20Janesville%2c%20MN-209_webview.jpg --- [MENU **](https://www.jfbrennan.com/dam-construction/underwater-construction#mobile-nav) Submit [![J.F. Brennan Company, Inc.](https://www.jfbrennan.com/hubfs/images/j-f-brennan-company-logo-horizontal.png) ![J.F. Brennan Company, Inc.](https://www.jfbrennan.com/hubfs/images/j-f-brennan-company-logo-horizontal.png) ](https://www.jfbrennan.com/) [MENU **](https://www.jfbrennan.com/dam-construction/underwater-construction#mobile-nav) ## Experienced, certified divers who know dams # Underwater Construction on Dams ![ADCI Logo](https://www.jfbrennan.com/hs-fs/hubfs/ADCI%20Logo.png?width=116&height=156&name=ADCI%20Logo.png) J.F. Brennan Company divers are experienced underwater construction specialists. Whether constructing new infrastructure or repairing existing infrastructure, our divers have the right training and equipment to complete a high-quality dam project. Backed by one of the largest fleets of inland marine construction equipment in the United States, no project is too large or too small for us to accomplish. Our divers repair underwater concrete, steel, and other structures in near-zero-visibility conditions. We also have the ability to perform cold-water dives, hot-water dives, dives in contaminated environments, and deep dives that require the use of a decompression chamber. Brennan is a proud member of the Association of Dive Contractors International, Inc. (ADCI), and all of our commercial divers are certified. We can mobilize anywhere in the continental United States in a timely manner while maintaining competitive rates. Having our own divers allows us to provide expertise on several repair options that can fit any budget. Our divers excel at underwater concrete placement, including preplaced aggregate concrete, cast-in-place concrete, and precast concrete. Using several types of formwork, Brennan has successfully repaired ice-damaged, degraded, eroded, and broken concrete that was previously hidden beneath the water's surface. We are also able to repair underwater steel structures. Specialty equipment, such as underwater saws, torches, and welders, enables our trained divers to remove or repair steel structures such as pipes, gate structures, trash racks, outfalls, etc. **Our abilities include:** - Inspections (FERC) - Concrete placement - Underwater welding - Pressure grouting - Ultrathermic (Exothermic) cutting - Light Detection and Ranging (LiDAR) - Mussel relocation - Golden mussel eradication support - Intake cleaning - Scour and erosion repair - Salvage - Radiological Contaminated Diving ## Underwater Dam Construction Photo Gallery ![2023 Portadam Install - Janesville, MN-209_webview](https://www.jfbrennan.com/hs-fs/hubfs/Diver%20Photos%20-%202025%20Recent/2023%20Portadam%20Install%20-%20Janesville%2c%20MN-209_webview.jpg?width=600&name=2023%20Portadam%20Install%20-%20Janesville%2c%20MN-209_webview.jpg "2023 Portadam Install - Janesville, MN-209_webview") ### Want more information on our underwater construction services? Fill out the form below! ![j-f-brennan-company-logo-horizontal](https://www.jfbrennan.com/hs-fs/hubfs/images/j-f-brennan-company-logo-horizontal.png?width=1465&name=j-f-brennan-company-logo-horizontal.png "j-f-brennan-company-logo-horizontal") [Privacy Policy](https://www.jfbrennan.com/privacy-policy) #### Main Office Location: 818 Bainbridge Street La Crosse, WI 54603 Phone: 608/784-7173 Fax: 608/785-2090 Payroll Fax: 608/881-6519 [All Brennan Locations](https://www.jfbrennan.com/contact-us) #### [Careers](https://www.jfbrennan.com/careers) #### 24 Hour Dispatch: 24/7 Service Call 800-658-9027 #### Workplace Posters: [Federal](https://www.jfbrennan.com/hubfs/Jobsite%20Posters/Federal-Jobsite-Posters.pdf) [States A-M](https://www.jfbrennan.com/hubfs/Jobsite%20Posters/States-A-M.pdf) [States N-W](https://www.jfbrennan.com/hubfs/Jobsite%20Posters/States-N-W.pdf) #### Connect: [**](https://www.instagram.com/jfbrennancompany) [**](https://www.facebook.com/Brennan1919) [**](https://www.linkedin.com/company/j-f-brennan-company-inc) [**](https://www.youtube.com/channel/UCcGPPk74MFOXwW2rN4EwgUg)   ![GPTW Certification 20-21](https://www.jfbrennan.com/hs-fs/hubfs/GPTW%20Certification%2020-21.png?width=35&name=GPTW%20Certification%2020-21.png)   [**](https://www.facebook.com/Brennan1919) [**](https://www.linkedin.com/company/j-f-brennan-company-inc) [**](https://www.youtube.com/channel/UCcGPPk74MFOXwW2rN4EwgUg) Copyright © 2015 J.F. Brennan Co. Inc.