Award of Excellence: Water Structures Category
Intake Structure Rehabilitation and Strengthening
Crystal River, Florida
Submitted by MAPEI Corporation
Progress Energy Florida, Inc.
Crystal River, FL
Premier Corrosion Protection Services
Deerfield Beach, FL
Water intake structures divert water from a river or channel for various purposes, including water supply, hydroelectric power generation, and irrigation. Engineers consider many factors when designing water intake structures. The withdrawal of water from rivers, lakes, or oceans to be used for the cooling of nuclear electric power plants or manufacturing facilities may result in adverse environ- mental impacts on aquatic life. These impacts include impingement, whereby aquatic life becomes pinned against filtering screens or other components of cooling water intake structures (CWIS), and entrainment, where aquatic life is drawn through CWIS and injured or killed.
This project involved the repair and strengthening of four intake structures for this facility located directly on a river in Florida. Each chamber has seven concrete support beams and was built in 1965 with no remedial work done to repair or protect the concrete from the harsh elements of a saltwater environment.
Each chamber is approximately 15 x 50 ft (4.6 x 15.2 m) and repairs were restricted based on the time of the high tide, as there was only 4 ft (1.2 m) of clearance between the base of the platform and the top of the overhead concrete slab. The overhead clearance problem was overcome by building floating platforms that were lowered into the chambers, where they were assembled and covered over with marine plywood. These floating platforms were built “wall to wall” with a gap of approximately 3 in. (76 mm) all around the perimeter to allow for the rise and fall of the tides.
All work was completed while parts of the intake structure were operational, incurring minimal downtime for the client. Completion was reached safely in only 3 weeks and—to the client’s delight—on budget!