The Environmental Impact of Water Reservoirs (Essay Sample)

The Environmental Impact of Water Reservoirs
Emmily Jepkoech
Quality Writers
The Environmental Impact of Water Reservoirs
During seasons of extremely low water flow, consumer demands may not be fully met whereas in seasons of high water flow residents may be faced with overwhelming floods. This therefore calls for the construction of water reservoirs to control the amount of water flow. Water collected and stored in reservoirs is used for purposes of generating hydroelectric power, irrigation, prevention of floods, and for industrial use. Besides the many benefits water reservoirs bring to communities and countries, it has been identified that along with the benefits come environmental impacts. The environmental impacts of water reservoirs that will be discussed in this paper include impact on water hydrology and river dynamics and the impact on soil and water quality.
Water reservoirs such as dams are constructed by creating river diversions upstream so that more water can flow into the reservoir and raise the water volume (McCully, 2001). This move can cause the landscapes to dry and cause changes to both surface and groundwater processes (Schleiss & Boes, 2011). Due to water storage along with the utilization of the reservoir levels for purposes of irrigation and generation of hydroelectric power, river dynamics are negatively affected through major alterations to its natural movements as well as changes in runoff circulations (Doll, Fielder & Zhang, 2009).
Chemical, physical, and temperature changes undergone by moving water when it is calmed can cause severe contamination of reservoir water and water in downstream rivers (McCully, 2001). The level at which the quality of the water worsens is related to the amount of time the water is stored in the reservoir along with the amount of water therein. Water stored for several months or years in a dam can cause serious harm to life both in the reservoir and in the river downstream because of high levels of sediment and nutrients such as the Lower Mekong River (Kummu & Varis, 2007). Normally, water in the reservoir has low levels of dissolved oxygen and its colder than river water, thus releasing these water can cause harm to plants and animals downstream (Hering, Carvalho, Argillier, Beklioglu, Borja, Cardoso, et al., (2015).
Water reservoirs impact on soil occurs when salinization takes place during dry weather conditions relative to irrigation due to retaining of high levels of groundwater because the rate of evaporation is high (Wildi, 2010). For instance, salinity in the Colorado River has in the recent past doubled due to the increase in sediments levels and dissolved solids (Tillman & Anning, 2014). Apart from affecting the environment, rising salinity levels in the Colorado River has also cost millions of shillings in mitigation and damages. In addition, polluted sediments from reservoirs are let out into the floodplains during floods resulting in the pollution of soil (Wildi, 2010).
Reservoir processes which include temperature cycles, evaporation, phosphorous and nitrogen cycles affect the surface quality of water (Tillman & Anning, 2014). When sedimentation occurs, the course elements mainly comprised of sand gets less in suspension while fine elements such as clay increase. This causes higher pollution and contamination of the water at the outlet of the reservoir.
Due to the many environmental impacts of water reservoirs, it is important that strategies that satisfy conditions of sustainability ...