A lake is a water body that acts as a water retention facility. It not only stores water which makes it efficient for flood control, but it also acts as a water source providing water for many purposes. The purposes include water supply, irrigation on farmlands, fisheries, tourism, among many others.
It also harbors numerous species of plants and animals and serves as a sink for carbon storage. However, when left unattended and under poor management, a lake cannot function fully to serve its purpose and can even be hazardous to the surroundings. Therefore, lake restoration is such a key factor when it comes to the management of lakes.
What is Lake Restoration?
Due to their depth, lakes can function as sinks making them prone to the accumulation of pollutants. As the amounts of pollutants increase, the toxicity levels also increase with time, resulting in the inability of the ecosystems to function properly and operate in self-sustaining ways.
This is where the management of lakes, rivers and other water bodies comes into play to address the interference or damages caused that the ecosystem cannot restore on its own.
Lake restoration involves the use of different techniques that are applied to bring a lake back to its original state or closer to conditions that make it habitable for aquatic plants and animals. Lake restorations utilizes the use of effective methods inside the lake as well as measures taken outside the lake such as improved wastewater treatment which helps in the reduction of the external nutrient.
Why is Lake Restoration Important?
Many benefits come with lake restoration and they include
Sediment management
The restoration of a lake, especially shallow lakes that involves sediment removal often leads to the eradication of toxic substances. Through sediment removal copious quantities of nutrients stored in the sediments can be removed along with other toxic substances, increasing the mean depth of the basin. In the long run, this prevents groundwater status deterioration.
Flood risk reduction
The accumulation of sediments in the lake basin often results in a high-water level since the depth of the lake is reduced due to the space occupied by the sediments. With time, the water levels might rise and with no other place to sit, the lake might break its banks leading to flooding. The lake restoration process through the removal of sediments allows the water levels to be maintained at a manageable depth.
Reduction of phosphorus and nitrogen levels
The lake accumulates nutrients, particularly phosphorus and nitrogen. This results in nutrient enrichment leading to excessive growth of algae and macrophytic plants and causes lower productivity.
Through lake restoration and treatments like advanced wastewater treatment and land management practices, the loading of phosphorus and to some extent nitrogen can be reduced. The phosphorus load in wastewaters can also be reduced by reducing the phosphorus content in detergents which most of the time end up in the lakes. However, the best way to reduce these levels is through eutrophication and the prevention of nutrient pollution.
Control excessive growth of macrophytes
Excessive growth of macrophytes and exotic species such as water hyacinth, hydrilla and duckweeds, can eliminate the use of lakes, especially when they grow and spread too fast. Water hyacinth and any other vegetation present in the lake that is a nuisance, causing eutrophication, must be removed. This can either be done manually or mechanically.
Chemicals like methyl-chlora-phenoxy-acetic acid, hexazinore among others can be applied to control weed infestation. If biological control is the preferred method, the introduction of Pila globosa (apple snail) or/ and Chinese grass carp (fast-growing fish) that feed on many aquatic plants can also be done to combat the situation.
Using the water table drawdown restoration technique, the lake can be made more habitable for aquatic animals like fish populations and the management of aquatic plants in the lakes improved.
Using macrophyte biomass control where measures are put in place to restore aquatic plant communities or eradicate the exotic species, macrophytes growth can be controlled.
Other benefits include better management of fish stocks, recreational opportunities enhancing tourism, prevention of biodiversity loss, prevention surface water status deterioration, natural biomass production, biodiversity preservation, aesthetic/cultural value, improving soils and Increase evapotranspiration.
What is Eutrophication?
Eutrophication is what occurs to estuaries and coastal waters as a result of a chain reaction in the ecosystem. It causes an overabundance of harmful algae and plants, dead zones, and fish kills. The plants and algae decompose and produce substantial amounts of carbon dioxide which occurs when the environment becomes enriched with nutrients leading to an increase in the amount of plant and algae growth.
The high levels of carbon dioxide lower the pH of seawater, a process called ocean acidification. High rates of acidification result in the slow growth of fish reducing the commercial catch which in turn affects the economy, food supply and sources of income due to smaller harvests. These excessive nutrient inputs end up degrading the lakes and other water bodies as well as cause the death of fish and seagrass due to low-oxygen levels.
Eutrophication can also occur due to the accumulation of sediments as the lakes age. But, recently, it’s been found that human activities are also to blame since they have accelerated the rate and spread of eutrophication.
Conclusion
Lake restoration using effective and applicable restoration programs is an important factor in maintaining a balanced ecosystem and addressing the correcting point and non-point sources of pollution.  At Karina Lakefront Maintenance, we understand the importance of lake restoration and its impact on the environment.Combined with regulations and proper planning for wildlife habitat and fishes, it’s possible to stop the declining water quality and the rate at which wetlands are lost each year. While the process might require proper planning and access to authority, funding, and active involvement from different levels of organisation to initialize the restoration programs, it comes with many benefits.