by Jessica Allen (WEST Fellow 2006-7)

Every single day you witness a miracle.  When you turn on your tap water comes out.  Have you ever thought, where does this water come from and how does it get here? Would you know what to do if water stopped coming out of your tap?

Salt Lake Public Utilities is a company of thousands of people that work to make sure that this miracle happens.  They would not call it a miracle but lots of hard work. This company provides water not only to you and your neighbors but to everyone in Salt Lake City.  That is almost 50 million people. All of these people use 210 million gallons of water a day.  That’s almost 2 billion pounds and 28 million cubic feet of water. That’s enough to fill in Eccles Stadium twice.  And we use this much water EVERY DAY.  

So again, where does it come from…it comes from the mountains and water stored underground.

The figure below shows the amount of water that comes from the Wasatch watershed (City Creek, Parley's, Big and Little Cottonwood streams), Deer Creek Reservoir and from groundwater via wells.

Here, we are going to focus on one river that provides water to Salt Lake City, the Big Cottonwood Watershed. A watershed is an area that drains into one river. Of all the watersheds or rivers that flow into Salt Lake City, Big Cottonwood provides the most amount of water for drinking. Big Cottonwood alone provides 22 million gallons of water EVERY DAY. If you drank a gallon a day, it would take you 60,000 years to drink this much water.

Here is a map of Wasatch Watersheds. (http://www.wrh.noaa.gov/Saltlake/river/presentations)

Remember 210 million gallons is an average. That means if you take daily measurements and average them over years and years you will get this number. Do you think you use the same amount of water every single day in the summer and the winter.  No, of course not. Salt Lake City uses much more water in the summer than in the winter.  Sometimes we use up to 219 million gallons of water.

Data from www.keepitpure.com

This graph shows you the changes in the amount of water that is flowing out of the Wasatch Watersheds. Does this graph match the time of year when more water is used in the city? Why do you think this is? What happens between May and August that makes us want more water? This same thing changes the amount of water flowing in the streams.

Big Cottonwood Canyon is very steep.  If you look at the graph below it shows you the slope or gradient of Big Cottonwood. Water travels so fast that it takes only ONE DAY or 24 hours to get from Silver Folk to your tap. Think about this....this water needs to travel down the stream, through the water treatment plant, through miles of pipes and up to you sink. All in under a day. 

From:  http://www.flux.utah.edu/~mike/climbs/gif/bigc.gif