Abstract
Clean water for domestic use is essential for a health population. Therefore, all people should have access to clean drinking water. Drought is a common phenomenon in arid regions and this makes water shortage a significant problem. The effects of water shortages are experienced in the arid Southwestern parts of the United States, this just being one among the many arid areas of the world. The paper seeks to address and compare the various small and large scale methods possible for water provision in this arid region of the United States. Among the large scale possible methods of providing water for this region include construction of dams and establishing water desalinization plants. On the other side small scale sources includes drilling of boreholes and rain water collection. This can have significant impact on the water availability in the region.
Introduction
The desert south west region of the United States has experienced drought over years. This region includes parts in southern California, south of Utah, southwestern Colorado, southern Nevada, Arizona and western Texas. This region is suitable for discussion due to a number of reasons. Firstly, the fallen water table in this region with diminished water flows and contracted lakes, increased demand for water due to the growing population, worsening effects of global warming, and restrictions imposed on water uses. Large and small scale methods for water provision are compared in this discussion. (Parker 2010).The demand for water on the counties to the southeast of California, New Mexico and Arizona States reveals a nine percent increase in water consumption in the period between 1985 and 2000. According to Gleick, Cooley and Groves (2005) the Californian institute of public policy projections indicates a water demand increase by 40% within the period 2000 to 2030.
Available water resources
Water sources vary in terms of quality and access and this makes evaluation of available resources within a region difficult to explore. The common water resources include ground water and surface waters.
Ground water
Ground water sources in this region can be found in the sedimentary rock layers within the basins of mountain ranges. This is found in the eastern escarpments within the southern plains across the west of Soronoa, Chihuahua and Mojave deserts. (Parker 2010 ). According to the United States geological survey, this underground water is easily harnessed where springs arise from the aquifer. Some aquifers can accumulate huge amounts of water according to the United States geological survey. The aquifers are recharged by rain water, snowmelt and at time through underground seepage of irrigation water. The depth of the aquifer determines the level of technology and the cost of making the water available. ( United States geological survey 2010).
Surface waters
The southwest region has its major surface water originating from the Colorado and the Rio Grande Rivers and their tributaries. According to the United States geological survey (2010) the Colorado River stretches for over 1400 miles with most of the river draining through the southwest arid region. This is usually fed by rain and snow water. There is wide variation in the amount of water flowing in the river throughout the year this is due to the “climatic fluctuations, drought, and flow in the Colorado river basin” according to the United States geological survey (2010). The Rio Grande River has much lower water volume than the Colorado River. At time it runs on a dry bed across the Chihuahua desert
Possible water provision methods in the southwestern arid region of the United States
Lakes and dams
Collecting waters in lakes and dams is essential where large consumption of water is needed. The south west arid region of the United States has a growing population increasing the demand for water. (Parker2005). Seasonal water from Rio Grande River and always flowing Colorado River can be collected in dams. The dams can be a single or a series of dams tapped from its tributaries. High level technology required to construct dams that are viable in the future. The cost of constructing dams is usually high compared to other means of water provision. The location of dams should be dictated by the topography of the site area. The construction has to be done with regard to the construction guidelines.
Desalinization plants
Desalinization plants can produce quality water for domestic consumption. The El Paso partnering with fort bliss has constructed “Kay Bailey Hutchinson” plant for water desalinization. The company uses unusable ground water to produce 27.5 m gallons of fresh water in a day. The company uses high technology to treat the water. (Kong & Holbert 2010). Several desalination plants can be constructed to handle the issues of water shortages in the region. However, the cost of constructing such plants is very high. For example El Paso plans to invest $425 million dollar plant to invest in desalination and piping facilities which is quite huge capital for investing in a single water project. Desalination plants can be established along the cost of Pacific Ocean to produce more clean water in the arid region. Other desalination projects also include reviving of includes reviving of Yuma plant. The water from these plants is good for agricultural use. (El Paso water services n.d).
Small scale water provision methods
Boreholes
Underground water sources can be harnessed with simple and complex technology. Wells can be developed in arid areas to meet small scale demands of water; however, it can also be developed to cater for huge demands of water. In areas where the aquifer has a spring it can be harnessed using simple hand technology. Huge technologies are required to identify potential ground water aquifers capable of producing high volumes of water. In this case dowsing and radar methods are convenient to establishing high potential aquifers with accuracy. (United states geological survey 2011) Improved technology and better hydraulics and hydrogeology knowledge allows exploitation of water in large scale. In the case where there is large population and the huge demands of water the aquifer is threatened to depletion. (Luis, Ian and Lacovos 2009). Ground water reservoirs depends on the geological information, thereby they can be metamorphic, sedimentary or igneous. The porosity and permeability of the aquifer determine the nature of the ground water. (Luis, Ian and Lacovos 2009). The cost of developing the large aquifers is very high, only governments with high economies can afford to develop this source of water.
Rain water harvesting
The methods involve collection of rain water for various purposes. The method has been used worldwide over centuries. The method can be categorized by six distinct forms of water collection. This includes the roof top harvesting, water for animal consumption; inter row harvesting, micro-catchment, medium sized and large catchment harvesting. (Prinz n.d).
This method requires various components for the water collection. The components include the catchment surface, channels for collection, components for filtration, storage facilities, delivery system and purification system. (Texas water development board 2005). The quality of collected water is affected by the environment, catchment surface and the storage facility. A suitable environment should be provided such as repair and maintenance of broken parts, tank levels should be checked and also cleaning gutters. In the southwestern parts of United States rainfalls during summer can be collected and stored for future use. Moderate cost is required to implement this method of water provision. It can be helpful in providing clean domestic water; however, it cannot satisfy the huge demand of water in this region. (Texas water development board 2005)
Comparison
Cost
Small scale sources are much easier to implement than large scale. For example, the cost of constructing a dam is very high. This is because the cost involves many variables such a cost of survey, human capital required if also expensive, the cost of construction material is high and high level of technology used costly. E.g. high recent technology is used by El Paso and associate to construct a very expensive desalination plant with a high production capacity. (El Paso water services n.d). This is different from small scale such as hand dug wells and rain water harvesting. The cost of harvesting rain water can be afforded by majority citizens unlike cost of dams cannot be met by individuals. It is for this reason that governments initiate large water provision methods.
Population served
Large scale water sources are the best sources of water since they ensure adequate reserve for the entire population. They can supply huge amounts of water to the population at a given point. This is unlike small scale sources like boreholes, where water has to accumulate over time and only a certain capacity can be withdrawn at a particular time. However they can supply small amounts for considerable time, the can only feed a small population. Small sources such as rain water can provide water to the entire population; however, this is not practical since majority may ignore the type of water collection.
Level of technology
Large scale desalination use high and sophisticated technology in the process of desalinization. High technology is also used in dam construction and in identifying high potential aquifer; E.g. radar and dowsing technologies are used. The higher the level of technology also determines the level of skilled labor as they have to be acquainted with the technology. Small water sources may require little or no technology. ( Luis, Ian & Lacovos 2009).
Geography
The geographical conditions for establishment of the water sources are different for each type of water source. Common condition for establishment of large scale sources includes availability of water, the geological characteristics should allow the setting of such facility and also the topography of the land should be able to withstand the pressures due to the water volume. For example, the location of a desalinization plant should be such that it’s close to a salt lake or an ocean or available unusable ground water due to high salinity. On the other hand small scale sources may depend on the climatic seasons, availability of springs and the topography. ( Luis, Ian & Lacovos 2009).
Recommendations
The for the high estimated population growth of southwestern arid region of the united states in the future, it is advisable to invest in large scale methods of providing water such as establishing more desalination plants and constructing dams on plain basins and on the river Rio Grande. In addition it is recommendable for the government to subsidize on equipments necessary for establishing efficient water collection system, as this would substitute water from other sources
Conclusion
Water shortage in arid areas is an issue that needs not to be ignored. Clean water for domestic use is essential for a health population. The region’s water shortages can be dealt with by variety of methods such as dams, desalination of water, exploiting high potential underground water and by harvesting rainwater. The best be adopted is that that whose profitability is worth the investment, serves people adequately and fits the geographical conditions. However, a combination of these methods would be suitable. In this case, the federal and the state governments will be responsible for large scale water sources and individuals can contribute in rain harvesting. This would lead to a better water supply.
References
Luis P. S., Ian C. & Lacovos L. 2009. Coping with water scarcity: addressing the challenges: springer
Prinz, D. n.d.Water harvesting: past and future. In: Pereira, L. S. (ed), Sustainability of irrigated agriculture. Proceedings, NATO advanced research workshop, Vumeiro, 21-26. 03. 1994, Balkema, Rotterdam, 135-144
Gleick H.P., Cooler H. & Groves D. 2005. California water 2030: An efficient future: pacific institute
Kong D. & Holbert K.E. 2010. Solar thermal electricity generation and desalination in the southwestern United states. North American power symposium
Parker K. 2010. Population, immigration, and drying of American southwest. [online] available at < http://www.cis.org/southwest-water-population-growth >
El Paso water services, n.d .Setting the stage for the future. [Online] available at <http://www.epwu.org/water/desal-infor-html>
Texas water development board. 2005. Texas manual for rainwater harvesting (3ed).Texas: Austin
United states geological survey, 2011. How do hydrologists locate ground water?. [Online] available at < http://ga.water.usgs.gov/edu/gwhowtofind.html>
United States geological survey. 2010. The water resources of united states. [online] available at <http://water.usgs.gov/> [assessed 12th April 2011]
