Geography 444 – Conservation

Water Resource Development for Los Angeles County Plan

By: Liron Edry



The County of Los Angeles (Map 1) is notoriously known for water shortages. This acute situation is further aggravated by persistent drought conditions as well as overuse of existing water resources for urban irrigation such as city parks and golf courses. Another element contributing to Los Angeles County’s water shortage is massive water waste by residents who over water their lawns and directly irrigating water onto concrete surfaces. As a result the wasted water supply either evaporates or is directed into storm sewer systems leading into the Pacific Ocean. Should those habits persist, future Angelinos would find themselves paying more for water transported into their county from distant sources. Therefore, a Geographic Information System based management system should be used to evaluate and help construct a responsible recycling system for runoff water that would in turn be used for irrigation, and possibly as drinking water.


Map 1: Study Area



Many cities face water shortage during dry seasons and dry years. Poorly developed lawn irrigation systems are part of this problem. Niemela found that 50% of the municipal water demand comes from lawn irrigation in Douglas County, Colorado (2007)[1]. Other research report that cities lose up to 60% of the water used for lawn irrigation due to inappropriate irrigation systems (Sharp and Garcia-Fresca 2003)[2]. Like many other places, Los Angeles is one of the cities in the American West that has been struggling with water shortage (Quinn 1968)[3], lack of construction of an adequate irrigation and sewage systems (Torres-Rouff 2006)[4], as well as a poorly constructed water distribution system (Xiao et al. 2006)[5]. Despite these problems, no solution has yet been found.

A well-written water policy and political involvement is one of the keys to solving the water shortage problem. Poorly constructed water policies in Santa Clara Valley have hindered the water system development process, by asking the wrong questions (Walker and Williams 1982)[6]. Another case of inadequate water policy was also seen in Owens Valley, California (Sauder 1989)[7]. However, in the Sacramento-San Joaquin Delta area, environmental legislation has helped in laying “the policy foundation for use of the land and water resources” (Mitchell 1994)[8]. No such policy has been strictly applied in Los Angeles.

Use of wastewater in irrigation has proven to be safe. Researchers in Colorado found that recycled wastewater were suitable for landscape irrigation. The same research had also found that “the use of recycled wastewater for irrigation in urban landscape is a powerful means of water conservation” (Qian 2006)[9]. Similarly, researchers at The Pennsylvania State University have proven that soils irrigated with wastewater were still performing well after a long period of time. Said research has been conducted for several decades (Walker and Lin 2008)[10]. This kind of research should be done in the Los Angeles area.

GIS could effectively manage a wastewater-recycling program. GIS modeling has been successfully applied to urban development. For example: GIS modeling was used in urban areas in Malaysia to help determine allocation of water (Ali et al. 2003)[11]. Pennsylvania State University researchers used GIS modeling to develop a storm-water management plan (Shamsi 1996)[12]. Urban developers in India have used GIS in their planning process, including the development of water supply networks (Saladin, Butler and Parkinson 2002)[13]. Other fields that have been using GIS modeling include agriculture (Knox and Weatherfield 1999[14]; Sadler et al. 2005[15]), and wetland mapping (Poiani and Bedford 1995)[16]. However, no one has yet applied a GIS based solution to a wastewater-recycling program in the Los Angeles county area.


City of Los Angeles Water Supply Action Plan[17]

In May 2008, the office of Los Angeles County Mayor Antonio R. Villaraigosa, with the help of the City of Los Angeles Department of Water and Power, produced a document called Securing L.A.’s Water Supply. This document is also known as City of Los Angeles Water Supply Action Plan. This document outlines the current water sources available for Los Angeles County, and the reasons for Los Angeles’ water shortage, along with short term and long term plans to deal with this deficit. It details the current water usages and suggests how to use new technologies in solving Los Angeles’ water crisis. However, this thirty-two page document, does not mention the possible benefits of using a Geographic Information System management system.

The City of Los Angeles Water Supply Action Plan document outlines the current water resources available for Los Angeles County. On an average year, Angelinos get fifty three percent of their water from the Metropolitan Water District, thirty five percent from the Los Angeles Aqueduct, eleven percent from local underground water, and only one percent from recycled water. This means that a total of eighty eight percent is imported into Los Angeles County from distant locations, and only twelve percent of the water consumed comes from local resource (Figure 1). However, the figure of local water resources has been reduced even further in recent years.


Figure 1 source: City of Los Angeles Water Supply Action Plan document


It seems that most of available underground water in Los Angeles County is found in the San Fernando Valley. These sources of underground water have been contaminated in recent years and are no longer a viable and reliable source of water to Los Angeles County. According to information obtained from Mayor Villaraigosa’s office, the City is currently trying to do all it can to find the responsible parties so those who are responsible would pay for the large expanse it takes to clean up the underground water. Until that day comes, many local wells are out of commission and cannot supply Los Angeles with a reliable source of water. Unfortunately, the reliability of underground water is not the only one being jeopardized.

Climate changes, along with global warming, contribute to inconsistent and unpredictable weather conditions. The state of California, and especially Southern California, is no stranger to sever droughts followed by heavy rainy seasons, that than are followed by a few more years of drought. These great variations in precipitation affect Los Angeles County as most of its water is transported from different regions. The water that Angelinos consume often arrives from far away places such the East Sierra-Nevada’s, the Sacramento - San Joaquin Delta, and the Colorado River. Inconsistency in water supply and precipitation (be it snow or rain) in those regions, greatly affect their water surplus. Furthermore, when those areas do not have much water “left over” after they are done using what they needed, they would either raise the price of water, and or reduce the amount of available water for purchasing all together. This is why a major action plan is required in order to secure water supplies in the future of Los Angeles County.

According to the City of Los Angeles Water Supply Action Plan document: “The ability of Los Angeles to succeed and thrive in the middle of a semi-arid desert depends on our willingness to make the choices necessary to secure water resources for years to come.” This document further indicates that “residential customers…account for 68 percent of water demand.” It is further indicated that “approximately 30 percent of total water is used outdoors” by both residential and commercial users (Figure 2). Some of the long term actions that should be taken are “reduction of outdoor water use and new technology, maximizing water recycling, [and] enhancing storm water capture.” With that being said, the City of Los Angeles’ water conservation actions goes back as far as the 1990’s, and some even as far as the end of the 1970’s.


Figure 2 source: City of Los Angeles Water Supply Action Plan document


Water shortage crisis is not new news for Los Angeles County residents. The last time Los Angeles faces a sever drought, and a consequential water shortage was in the 1990’s. During that time, the City of Los Angeles has taken some major actions in order to secure and maintain its water resources. Part of this action included changing many of the water-wasting toilets with ultra low flush toilets. This was done in government and commercial buildings, as well as in private residence. Furthermore, many shower-heads were replaces with low-flow showerheads. This action saved, and still saves, the County of Los Angeles billions of gallons of water every year. However, now that most indoor water conservation opportunities are nearly exhausted, Los Angeles Department of Water and Power must turn its focus on investing more resources on technologies that would reduce outdoor water usage.

As mentioned above, according to the City of Los Angeles Water Supply Action Plan, thirty “percent of all water used by all customers” is used for watering lawns as well as other outdoor water uses. A portion of this amount is wasted on over watering, and watering concrete surfaces. This over flow of wasted water than finds itself in the storm drain system, and than in the Pacific Ocean. Several steps have been suggested in solving this problem.

The first step in solving lawns over watering problem is to invest in something called smart sprinkler systems. According to the City of Los Angeles Water Supply Action Plan those new smart sprinklers are a “new technology that adjusts irrigation schedules based on local weather conditions.” The second step is to capture and recycle any overflow water, as well as actual storm water, which would increase water savings for Los Angeles County in the present and in the future. This, it seems, would not be the first time Los Angeles County has captures storm drained water and reused it.

“Los Angeles has used recycled water since 1979 for irrigation and industrial purposes” in many locations according to the May 2008 ‘Action Plan’. The recycled water was mostly used for parks, golf courses, recreational facilities, and in various industries. The next step in recycling water would be to turn it to a good source of drinking water. Once this is done, “advanced treated recycled water can be sent to spreading basins to percolate underground and become part of the City’s ground system for later use. This process - also termed groundwater replenishment - is a proven alternative for expanding locally produced, safe, high quality drinking water.” The goal of that project would be to increase “long-term groundwater recharge.”

The above is an outline of the key points from the City of Los Angeles Water Supply Action Plan. With the short term, and long term plans, it seems that everything is under control. There are even plans of expanding some of the local water recycling facilities, but those would not add the much needed amount of water that is required to keep up with the rapidly expanding population of Los Angeles County which is estimated at 0.4 percent annually. More water recycling plants should be built, and more pipelines should be put in the ground, and this is where a Geographic Information System management system would come into play.


The Plan

In order to solve the continuous water crisis that is afflicting Southern California and Los Angeles County in particular, there should be a multi-county task force put together. This would include Ventura County, Los Angeles County, San Bernardino County, Riverside County, and Orange County. Other counties may join in on this plan as they see fit. At that point an implementation of a Geographic Information System would be appropriate in evaluating Hydrological processes, appropriate places to build water recycling plants, land ownership, and methods of delivering the recycled water to consumers. An attention should also be paid to possible benefits and damages to local ecosystems. Once that is done, the percentage of recycled water use should rise to higher levels.

A Geographic Information System has the ability to evaluate hydrological processes in a given area. This system is capable of examining elevation, determining the direction of water flow, and constructing a model of different watersheds. This mapping project is already on its way, and is conducted by the Southern California Coastal Water Research Project[18]. A sub-division of this project is the Southern California Wetlands Mapping Project[19] headed by Dr. Shawna Dark of California State University, Northridge. In this project, Southern California’s entire coastal watershed is being mapped and all hydrological processes are being captured in a visual way, using Geographic Information System software to present maps containing streams, rivers, springs, lakes, estuaries, wetlands, flood plains, and much more. Information obtain from this project, which the author of this paper is partakes, can be used for further analysis.

Following this process, the Geographic Information System would evaluate elevation models to determine appropriate places to build wastewater recycling plants. In this step, geological processes would be examined. This would include fault lines locations, as well as soil and rock type, to determine the best location for those recycling plants. Elevation would also play a major role in determining the location of the water recycling plans, as there should be the least amount of energy wasted on transporting the recycled water to those plants.

The next step would be to determine the appropriate paths for constructing pipelines that would transport the recycled wastewater to consumers. The information about the current pipelines would be uploaded to the Geographic Information System software. Should this information not be available in the form of a map, a spreadsheet with the pipeline information can be geocoded and a map would be created and overlaid on top of a topographic model. Using both layers of information, the new and existing routes for the new pipeline construction can be created. The best routes can be constructed by examining and analyzing distance, elevation and obstacle, and than produce the cost estimation of constructing new pipes.

When looking at the possible pipeline route, land ownership must be taken into consideration, as certain private lands may not be used in the construction route, and other possible solutions must be considered. It may also be of benefit to build water towers in the neighborhoods that would be supplied with the recycled water. This way, energy would be used only to pump the water up the tower. Once that is done, the water table would be elevated, which would not require additional energy wasted on pumping water for individual consumers.

The last step in constructing the new recycled water system would be to evaluate possible damages to local ecosystems. When any new construction project is suggested, the affect on the local ecosystem must be taken into consideration. Questions such as if there are any endangered animals, or any old protected trees and other type of vegetation in the area must be asked. This kind of cause and effect analysis can be done using a Geographic Information System program that would provide visualization of the possible damages.

Spatial maps that would be used in this project can be found on the USGS Education Website[20] under California: Geography, Geology, Hazards, and Natural History Information. Some of the maps that may have more weight on decision making should include: Parks and Public Land - this would help knowing where to run pipelines that would not go across private properties. California Geology map would help in recognizing land type and finding stable land to build recycling plant on. Major Faults of California map - this would help in making sure plants are not being built on top of a fault line, which can end up being damaged in case of an earthquake. California Landslide Hazards map - this map would also help in determining appropriate locations of stable grounds that can be used to build recycling plants. Lastly, Water Resources Map of California with Precipitation information would be helpful in delineating watersheds, water flow, and precipitation patterns.



As illustrated above, a plan to increase the amount of wastewater recycling in Los Angeles County is an elaborated task that cannot be taken lightly. This process requires a large amount of data along with various types of analysis. It is simply impossible to just pick a spot to build a wastewater recycling plant without weighing all the downfalls and benefits. People from different professions, with different backgrounds would have to work on this project together with a Geographic Information System analyst in order to come up with the best solution. Therefore, more research should be done on this subject, and a solution is sure to be found with the help of a Geographic Information Systems management system.



Citation and Bibliography:

[1] Niemela, Daniel. 2007. Irrigation season water level changes in municipal Arapahoe Aquifer wells, Douglas County, Colorado. Abstracts with Programs Geological Society of America. October, Vol. 39, Issue 6, pp.43

[2] Sharp, John M.; Garcia-Fresca, Beatriz. 2003. Geological Society of America, 2003 annual meeting. Geological Society of America. November, Vol. 35, Issue 6, pp. 158.

[3] Quinn, Frank. 1968. Water Transfers: Must the American West Be Won Again? Geographical Review. January, Vol. 58, No. 1, pp. 108-132.

[4] Torres-Rouff, David S. 2006. Water Use, Ethnic Conflict, and Infrastructure in Nineteenth-Century Los Angeles. Pacific Historical Review. Vol. 75, No.1, pp.119-140.

[5] Xiao, Q.; McPherson, E.G.; Simpson, J.R.; Ustin, S.L. 2006. Hydrologic processes at the urban residential scale. Wiley InterScience (October 12),, DOI: 10.1002/hyp.6482.

[6] Walker, Richard A.; Williams, Matthew J. 1982. Water from Power: Water Supply and Regional Growth in the Santa Clara Valley. Economic Geography. April, Vol. 58, No.2, pp. 95-119.

[7] Sauder, Robert A. 1989. Patenting an Arid Frontier: Use and Abuse of the Public Land Laws in Owens Valley, California. Annals of the Association of American Geographers. December, Vol. 79, No.4, pp. 544-569.

[8] Mitchell, Martin D. 1994. Land and Water Policies in the Sacramento-San Joaquin Delta. Geographical Review. October, Vol. 84, No. 4, pp. 411-423.

[9] Qian, Yaling. 2006. Urban landscape irrigation with recycled wastewater. Completion Report Colorado Water Resources Research Institute. March.

[10] Walker, C.; Lin, H.S. 2008.Soil property changes after four decades of wastewater irrigation; a landscape perspective. Catena Giessen. March 15, Vol. 73, Issue 1, pp. 63-74.

[11] Ali, Hazrat; Teang Shui, Lee; Walker, W.R. 2003. Optimal water management for reservoir based irrigation projects using geographic information system. Journal of Irrigation and Drainage Engineering. 129.1, January-February, p. 1.

[12] Shamsi, Uzair M. 1996. Storm-water management implementation through modeling and GIS (geographic information system). Journal of Water Resources Planning and Management. 122.n2, March-April, pp. 114(14).

[13] Saladin, Matthias; Butler, David; Parkinson, Jonathan. 2002. Applications of geographic information systems for municipal planning management in India. Journal of Environment & Development. December, 11.4, p430(440).

[14] Knox, J.W.; Weatherfield, E.K. 1999. The application of GIS to irrigation water resource management in England and Wales. The Geographic Journal. March, 165.1, p90(9).

[15] Sadler, E.J.; Evans, R.G.; Stone, K.C.; Camp, C.R. 2006. Opportunities for conservation with precision irrigation. Journal of Soil and Water Conservation. November-December, 60.6, p371 (9).

[16] Poiani, Karen A.; Bedford, Barbara L. 1995. GIS-based nonpoint source pollution modeling: consideration for wetlands. Journal of Soil and Water Conservation. November-December, 50.n6, pp613(7).

[17] City of Los Angeles Water Supply Action Plan (this refers to al the quotes in this section of the paper)

[18] Southern California Coastal Water Research Project,

[19] Southern California Wetlands Mapping Project,

[20] USGS Education, http://education.usgs.gove/california/resources.html#water