Dam Construction
Areas of Focus
Intakes and Headworks
At every stage of dam construction, the stability of intakes and headworks are critical components – and that’s where Brennan excels. From new structures to replacing worn parts, our team delivers complete solutions with precision and reliability.
Structural Steel
We specialize in the construction and replacement of critical structural steel elements for dams and water control systems. By collaborating closely with dam owners and engineers, we develop practical construction approaches and deliver cost-effective solutions for even the most complex rehabilitations and new installations.
Steel & Mechanical
Our mechanical capabilities go far beyond gate operations. We tackle precision manufacturing, alignment, and installation across all steel and mechanical components in water control structures. Whether it’s a new install or rehabilitating existing equipment, we provide complete, turnkey service with dependable maintenance.
Cofferdams
When water stands between you and completing the job, a well-designed cofferdam makes all the difference. At J.F. Brennan, we bring decades of experience installing all types and sizes of temporary structures that enable safe, dry work in submerged environments.
Cofferdam Installation
Our team has the expertise to fabricate, install, and maintain a wide range of cofferdam systems, ensuring each structure is tailored to site conditions, minimizes risk, and provides a dry work area.
Dewatering & Water Management
J.F. Brennan provides complete dewatering and water management solutions to keep work areas safe and efficient. From bypass pumping and groundwater control to temporary diversions, we design and maintain systems tailored to site conditions. Our approach protects structures and ensures smooth, uninterrupted construction.
Concrete Placement & Repairs
From new builds to precision repairs, Brennan delivers concrete placement solutions built to stand the test of time. Our crews work above or below the waterline, using proven methods and innovative techniques to ensure strength, durability, and efficiency on every project. Brennan has the expertise to construct new or rehabilitate existing:
- Canals
- Flowlines
- Intakes
- Lock Chambers
- Outflows
- Penstocks
- Piers
- Powerhouses
- Sills
- Spillways
- Tailraces
Mass Pours
We excel at executing large-scale concrete pours under challenging conditions—remote locations, limited access, and tight schedules. No matter the type of contract, our teams coordinate closely with clients, engineers, and subcontractors to ensure every pour meets stringent quality, safety, and timeline requirements.
Concrete Repairs
We specialize in restoring dam concrete with precision and durability. From debris removal to surface preparation, we use proven methods like precast, grouting, leave-in-place formwork, and preplaced aggregate concrete.
Grouting
We offer expert grouting services for dam infrastructure to extend life for degraded or leaking structures. Our crews use void-fill, water-cutoff, and structural consolidation grouting techniques—including cementitious, chemical, and cellular grouts—to seal leaks, fill voids, and reconnect foundations.
Gate and Actuators
Gate Replacements & Installation
Brennan specializes in the replacement, rehabilitation, and installation of mechanical water control gates of all types and sizes. Our teams use innovative, cost-effective approaches to complete full replacements, targeted repairs, or even complete in-place rebuilds when full removal isn’t practical. With decades of experience working on complex dam and lock structures, we deliver durable, precise solutions that restore functionality and extend the life of critical infrastructure.
- Bascule
- Crest
- Headgates
- Inflatable
- Lift
- Roller
- Sluice
- Tainter (Radial)
- Miter
- Wicket
Mechanical and Millwright Services
In addition to gate replacement, Brennan provides comprehensive millwright and mechanical services for gate control systems and related components. Our work includes hoists, chains, trunnion pins and bushings, actuators, seals, heaters, and deicing systems. By combining engineering expertise with field innovation, we’ve developed proprietary tools and processes that enhance safety, efficiency, and performance during installation and repair. This creative, solutions-driven approach consistently delivers cost savings and improved reliability for our clients’ mechanical systems.
Grouting
Grouting can extend the life of existing structures that have experienced severe degradation due to scour or freeze/thaw damage. It rarely involves the need for heavy equipment, resulting in an economical method of restoration. Brennan performs several types of grouting both above and below the waterline with experienced divers and topside crews working closely together.
Void grouting
We have a lot of experience grouting in areas between dam structures and their foundations. Voids caused by scour and erosion are common in water based infrastructure. Grouting reconnects the structure with its footings and subsurface piling. In some cases where there are unbraced lengths of piling, grouting will be used to establish a long-term reinforcement. We also use void grouting to fill around pipes and penstocks.
Water cutoff grouting
Water cutoff grouting is the process of injecting grout into the ground to stop water from creating subsurface voids. This includes grouting cracks or other imperfections in concrete, rock, or other substrate. For water cutoff grouting we use with chemical or cementitious grouts dependent on ground conditions.
Structural Repairs/ Consolidation
This includes epoxy grouting of cracked or damaged concrete to reestablish strength. This is very common in degraded structures that may have voids underneath the surface. For example, masonry walls can be grouted to consolidate the wall back into one mass.



