Chapter 12: The Great Plains and Prairies

The Great Plains are located in the nation's central section from Montana and North Dakota in the north and all the way south to Texas.  While the popular notion is that this region is entirely flat, the topography is actually highly variable with hills and uplands.  This area also is subjected to extreme weather such as tornadoes, blizzards, and thunderstorms. We are blessed with beautiful weather but still sometimes suffer from earthquakes and fires.  Other than the occasional occurrence of  violent weather, San Diego, California does not have much in common with this area of the United States... 

The Great Plains

Water is the single most important resource in the great plains.  A great portion of the High Plains are underlain by the vast natural Ogallala aquifer.  This aquifer supplies water for irrigation along with naturally occurring precipitation.  San Diego and Southern California as a whole is extremely water conscious.  Our water reserve levels are continuing to decline and as the dry summer months are coming up, Southern Californians are asked to cut back wherever possible...but where does San Diego get it's water from?

• About 10-12% of San Diego's total water supply is collected from precipitation into local reservoirs.  The remaining 80-90 percent is imported via the Metropolitan Water District of Southern California (MWD) and the San Diego County Water Authority (CWA) from two separate sources.  
• San Diego receives a portion of it's water from the an aqueduct connected to the Colorado River.  San Diego also receives water which originates in Northern California from the State Water Project. This water is captured in reservoirs north of Sacramento and released through natural rivers and streams into the Sacramento-San Joaquin Delta. The 444 mile-long California Aqueduct then carries the water from south of the Delta to State Water Project contractors throughout the state such as MWD (sandiego.gov).
• The MWD blends Colorado and State Project water for San Diego to achieve the highest quality for treatment and taste. The water is then transferred to the San Diego treatment plants at Miramar, Alvarado and Otay reservoirs, via pipelines operated by CWA.           

The Colorado River

California Aqueduct

Area covered by the Ogallala Aquifer