How Wetlands Provide Free Flood Control

Coastal wetlands are ecosystems that serve many valuable functions; they are important sources of food and fresh water. They provide valuable services, including water treatment and erosion control. Wetlands filter water and provide habitat for a number of animal and plant species. They also serve as recreational areas for various outdoor activities. Wetlands comprise large extensions of coastal land and are highly valuable because they protect coastal land from flooding and damage caused by natural phenomena, such as hurricanes and storms.

What are wetlands?

Wetlands are large extensions of valuable land that occupy approximately 6% of the world’s surface land. The wetland ecosystem is strongly influenced by aquatic ecosystems. Wetlands are regions of land saturated with static or flowing water, which can be fresh, brackish or salt water. Wetlands can be of four kinds, including marshes, fens, bogs and mangrove swamps. Wetlands provide habitat and spawning grounds for a wide variety of birds, mammals, reptiles, amphibians and fish species. Wetlands help regulate ecological processes, such as recycling of nutrients and human waste. They also provide flood control and water flow regulation.

Water storage reservoirs

Wetlands are particularly important because they help protect coastal land from flooding and damage caused by storms. The floodplains of major rivers, such as the Amazon River in South America or the Mississippi River in North America function as natural water storage reservoirs. During heavy storms, wetlands function as natural sponges that trap rainwater within its soil, diminishing flood heights due to storms. The energy produced by ocean waves that otherwise produce great coastal land damage is absorbed by coastal wetlands.

Natural defenses

Coastal wetlands, including coastal reefs, saltmarshes and mangroves serve as frontline defenses against potential devastation. The root systems of wetland vegetation bind together along the shoreline, resisting erosion by strong winds and ocean waves, and thus providing a natural barrier that slows down tidal waves and storm gushes. According to, the storm surge from Katrina was so devastating that the loss of wetlands represented one of the highest in the world. A category 5 hurricane could produce flooding of up to 10.5 meters (35 ft.) within the city of New Orleans by the end of the 21st century.

How wetlands provide free flood control

Wetlands provide protection and stabilization to the coastland zone. Coral reefs act as protective barriers to the coastal shoreline against high tidal waves and storms. Mangroves help stabilize the coastal zone from these effects from inland. The main benefits of these two systems are their ability to mitigate the speed and height of ocean waves and floodwaters. According to, world cities, such as New York are considering investing on artificial wetlands that could absorb the power of waves before reaching land. Wetlands could naturally purify water for free.

Natural filters

The surface water in wetland ecosystems only represents a small portion of the total water cycle which includes atmospheric and ground water. Wetlands function as important water regulators of underground water. Wetland ecosystems consisting of porous sediments, such as limestone allow the filtering of water down through the surface soil and into subterranean aquifers. Groundwater is an important source of water for drinking and agricultural irrigation purposes. It is estimated that water scarcity will be one the major concerns in the 21st century.

Wetlands play an important role in water purification and shoreline stability. Wetlands are considered as one of the most biological diverse of ecosystems and provide the habitat for a variety of animal and plant species. According to, wetlands provide an important benefit as flood controllers along rivers, streams and coastal shorelines by absorbing rainfall and protecting coastal zones from high energy ocean waves and devastating effects of hurricanes and heavy storms.