Floods that lead to unusually high water levels in natural bodies of water can cause the collapse or erosion of land along shorelines. This wearing away of the shore, slopes and banks can cause major problems for your property. It is important to learn about the various causes of floods and the methods we currently have for protecting your shoreline property from flood erosion.
How Do Floods Occur?
There are three potential scenarios where flood erosion can pose an issue.
Insufficient Drainage
When heavy rainfall affects an area not prepared with adequate drainage, serious erosion can result. Otherwise referred to as flash floods, these events cause water to rise in creeks and rivers. They may come on suddenly with little forewarning. Many flash floods occur at night. In other instances, periods of drought can cause the soil to become overly dry. When a flash flood occurs following a drought, the soil may not be enough to absorb the water in the short term leading to a flood event.
Heavy Rains
Flooding can result when an area experiences substantial amounts of rainfall over a prolonged period. The flood may even persist long after the storm has passed. In some instances, there is a lag between the rain event and flooding as water traverses through the rivers and creeks. Flooding does not necessarily require heavy rains if waterways experience significant precipitation.
Hurricanes and Tropical Storms
Storm-surge flooding in areas prone to hurricanes and tropical storms can cause a buildup of excessive amounts of water along coastlines. The low pressure of the storm may cause water to rise. Coupled with high winds and waves, the water can become pushed from the ocean and bays inland.
How Do Floods Contribute to Erosion?
Erosion control measures should be considered for flood-prone areas along shorelines, beaches, and bluffs. Floods can wash away portions of beaches and shorelines, leaving property owners with less land. During a flood, erosion is not necessarily a slow process. Sand dunes that took decades to form can be swept away in hours when subjected to hours of high winds and torrential rains. These powerful forces can decimate banks, shorelines, beaches, and bluffs. Structures and properties along these areas can become damaged as a result. In the United States, coastal erosion costs an estimated $500 million in coastal property loss from structures and loss of land.
How to Protect Properties from Erosion in Flood Prone Areas
To protect against flood erosion, property owners should seek a temporary, permanent, or biodegradable solution that can prevent the collapse or erosion of land while simultaneously protecting life and the local ecosystem along the shoreline.
Seawalls
Seawalls can be effective erosion control structures but may not be the best solution. When placed along sensitive and dynamic areas like shorelines, the walls can prevent damage to adjacent properties and the local ecosystem, at least for a brief time. Wave energy is not absorbed when a seawall is placed parallel to the shoreline. Rather, the wave is redirected in all directions along the face of the wall. Wave energy directed downward causes erosion and scouring of sediments and wetland vegetation at the structure’s base. The added water depth allows greater wave energy to reach the structure. Eventually, the structure will collapse.
Another problem seawalls face is that waves directed upward over the wall can damage or destroy the very structure the seawall was placed to protect, including your beachfront property. Flooding can result when the water becomes trapped behind the seawall. Furthermore, wave energy focused by a fortified shoreline can result in more rapid erosion of nearby vegetation and sediments, resulting in the loss of neighboring waterfront properties.
Alternative flood and erosion control measures should be considered along beaches and shorelines to prevent these problems from occurring.
Sand Bags
Sandbags are a temporary erosion control solution that can be used when other solutions are not readily available. Sandbags placed in the direction of water flow with no space in between can control flood waters and prevent erosion from worsening. The bags must be stacked, so the second row is staggered on top of the first. Stacks should be limited to three layers, or the bags may become unstable.
A major issue with sandbags is the question of disposal after the flood waters have receded. This is because the sand may become contaminated by the flood waters and should never be used to fill playgrounds or sandboxes used by children. The sand should never be disposed of in wetlands, waterways, or flood plains.
Vegetated Concrete Block Mats
Concrete block mats are a permanent solution for erosion control around flood-prone areas. These structures work with vegetation to provide natural protection against the heavy forces associated with storms and floods. The mats are made from organic materials and synthetic materials. These erosion control solutions are easy to install, cost-effective, and resilient enough to withstand the heaviest floods.
The protective sheets come in rolls. A small crew can install thousands of feet along a shoreline daily. The erosion control system reduces soil erosion on slopes, shorelines, beaches, and bluffs. Once installed, they stabilize the ground, absorb energy from heavy waves, and retain enough moisture to facilitate vegetation growth. Plants taking root can integrate with organic and synthetic materials to further stabilize the soil. This makes the sheets an environmentally friendly solution that can protect the shoreline from erosion while adding extra protection for surrounding properties.
Protect Your Flood Prone Property with Effective Erosion Control Solutions
Floods can occur from inadequate drainage, flash floods, and heavy storms. If you want to protect your property from flooding with erosion control, contact Flexamat. We offer permanent erosion control products that fit any project scope, big or small. Ask about our concrete mats that can be planted with vegetation for added flood erosion control before the next big storm hits.