Challenges that the City of Alexandria faces in managing stormwaters
The stormwater management program is composed of activities that have been designed to reduce pollution which is caused by stormwater. Stormwater is defined as water from rain or snow which has melted which does not get absorbed in the ground. Stormwater flows to the nearby water bodied like lakes and rivers. Stormwater carries with it foreign materials as it flows on the ground. The foreign materials include chemicals, oil, grease, and other contaminants that act as water pollutants.
The water then flows to water bodies like lakes and rivers without getting any treatment. Pollution and erosion are some of the problems of keeping water clean in the city. Water pollution is dangerous to water animals like fish. Stormwater is also dangerous because it leads to floods. Since this water is not absorbed in the ground, it can cause floods, especially in low lying areas. These are some of the challenges that face Alexandria in its effort to provide clean water. Stormwater management is therefore important to avoid flooding and pollution of water bodies (Congress, 2003).
Detention methods the city uses
The city of Alexandria requires measures of controlling erosion so that sediments are prevented from washing from the streets to the water bodies. Some projects must be applied to Stormwater management. They include construction, land development, and landscaping. These projects will help in the reduction of soil erosion.
Low Impact Development the city uses
Low Impact Development is a technique of development and design used in the preservation of the quality of water through the use of structural and non- structural methods. LID is beneficial because it reduces the costs of infrastructure and also reduces the costs incurred by the government in water conservation. These practices also control pollution.LID methods are important because of the provision of clean drinking water.
Water is also preserved for use during the dry seasons. The practices control small hydrologic storms which occur frequently and which have negative effects on the ecology. Three processes take place after precipitation. Water runs-off and is drained in the water bodies like lakes and rivers. Water is also lost to the atmosphere by evaporation a process called evapotranspiration. Plants also take in water. Water is absorbed to the ground through a process known as infiltration (American Planning Association, 2006). The three processes are used in the management of precipitation.
Best stormwater management programs used by the city
The flow of stormwater is reduced by employing activities which help in reducing the speed of the flow of water and also reducing pollutants. Management practices are used to minimize the impacts of running water. These techniques are generally referred to as best management practices. The practices mainly focus on the improvement of the quality of water while others focus on the control of the quantity of water.
ome practices however perform both functions. Some of the best management practices include the use of green roofs. The green roofs contain soil and plants which absorb and filter water thus reduces the speed at which it flows. As the water flows through the grasses, the speed is reduced thus preventing soil erosion (Congress, 2003). Permeable pavements are used for example concrete and paving blocks that allow infiltration into the soil are used.
Drainage problems can be solved through the use of underdrains. This prevents flooding caused by water accumulation. Filter strips are used to slow down the flow of water and they are placed at the water source (American Planning Association, 2006). The filter strips also prevent pollutants from flowing by trapping them. They are used in the treatment of water. Finally, another practice used is a soil amendment.
The contents of the soil are amended by adding other substances like lime and composite. Amending the contents of the soil makes it more permeable thus it can absorb more water. This reduces the amount of water running away as well as the prevention of the transportation of pollutants. Viability in plants is also enhanced.
Stream restoration in stormwater management
Stream restoration means reconstructing a river. Due to erosion, the soil is removed from the banks of the river. Conservation of soil erosion in rivers is important and this is done by stream restoration. Through soil erosion prevention, the environment is controlled. Strawberry Run in Alexandria slowed down the movement of water (American Planning Association, 2006). The stormwater management practice in Alexandria aimed at controlling the quality of water. This should be the main objective of all people because water conservation is a necessity.
References
American Planning Association. (2006). Planning and urban design standards. New York, NY: John Wiley and Sons.
Congress. (2003). Congressional Record. London: Government Printing Office.