Raising a seawall isn't a simple task of adding height to the existing structure. The most effective and sound method is to install a completely new seawall that meets municipal height regulations. Simply adding to an existing wall, like a "seawall cap overpour," can be more harmful than helpful.
Why Building a New Seawall is Best
Increasing a seawall's height significantly increases the exposed portion of the wall, demanding more structural strength. An existing seawall may not possess the necessary foundation or design to support the added weight and increased pressure from higher water levels. A new seawall allows for proper engineering and construction to account for increased height requirements and anticipated future sea level rise.
Alternative Approaches and Considerations:
While building a new seawall is the recommended approach, other options exist depending on specific circumstances and regulations:
- Rehabilitation and Reinforcement: Existing seawalls can sometimes be rehabilitated and strengthened to accommodate a modest height increase. This often involves extensive repairs, reinforcement, and potentially underpinning the existing foundation. This approach is only suitable for minor height increases and requires a thorough engineering assessment.
- TRULINE Seawall Installation: For certain situations, installing a vinyl seawall system like TRULINE in front of an existing wall can effectively raise the overall height. This method might be less disruptive than a full replacement, but its applicability depends on the existing wall's condition and the desired height increase.
Municipal Regulations and Approvals:
Before undertaking any seawall modification, it's crucial to check with your local municipality. They will specify minimum and maximum allowable seawall heights, along with necessary permits and engineering standards. Failure to comply with regulations can lead to penalties and even necessitate demolition of non-compliant structures. The height allowance will be influenced by factors such as coastal erosion, storm surge predictions, and local environmental regulations.
Examples of Seawall Projects:
Many projects illustrate the importance of proper seawall construction or replacement when increasing height:
- The US Naval Academy's seawall project focuses on repair and height increase to address future high tides and storms.
- Numerous cities, like Fort Lauderdale, Florida, are addressing seawall height requirements in ordinances to improve flood protection.
- Projects like the one at Castillo De San Marcos National Monument highlight the need for detailed planning and documentation when raising seawalls.
Remember, always prioritize safety and consult with qualified engineers and contractors experienced in coastal construction.
