How does a reservoir work?

   Water flows into reservoirs from different sources.  It can be surface water from lakes, rivers, streams, and rain.  It can also be from groundwater sources.   Any of these can flow into the reservoir naturally--that is, without help from man.  The reservoir could be in a place where the water would flow into it by itself.  Other reservoirs have water pumped into them and might be further away from where the water actually comes from.  Some reservoirs have pumped and natural water.
   When water leaves the reservoir, it is not treated for anything.  That is the job of the town that buys the water.  It does get a little filtration before it leaves.  This is done to take out big things that fall in the water so that they don't jam up the pipes and machinery when it is pumped to other places.  The machine on the left can lift logs and heavy things from the water.  It filters out fish, leaves, and things like that, too.  
    The two large reservoirs that we visited are linked by large underground pipes.  We were amazed to find out that when it was built, it took 3 years for the largest one to fill up.  When one gets low, water is pumped through large pipes from the other reservoir.  You can see from the pictures below, that these pumps are huge!   We are standing next to just one of the pumps that are in the left hand picture.