Saturday, September 04, 2010

Labor Day Weekend, Day 2: Garrison Dam and Power Plant

(See also Days 1-2: Jerrett's Birthday | Day 2: Audubon Nat'l Wildlife Refuge)

It was a 15- or 20-minute drive from Coleharbor to the Garrison Dam and Power Plant facility located between Riverdale and Pick City, ND.  The highway that passes through both those towns is actually laid atop the dam itself!  We have traveled it numerous times, and, as we drive, we always enjoy looking out across Lake Sakakawea to the north and down into the Missouri River valley to the south.  We often pull off the road at the scenic view spots on either end of the dam to take a closer look and get some photos.  From those locations, we have looked down at the buildings and structures on the dry side of the dam and wondered what's inside them.  Well, today we found out!

It's a secure facility surrounded by gates (we had to be let in and out by someone inside who controlled the rolling gate at the top of the road into the power plant), and we were told before we entered the building to leave cameras, purses, bags, etc., in our vehicles.  Once inside, though, we were allowed to see a lot of locations and equipment.  Our tour guide had been at her job for a couple decades, so she knew her spiel well, and she was able to answer any and all questions tossed at her by members of the group touring at the same time as our family.

We learned how the water goes into the intake structure on the wet side of the dam through penstocks past the surge tanks into the turbines connected by shafts to the generator units to create electricity before being released into the Missouri River (got all that?!).  The size of the facility and the equipment required to operate it is literally awe-some, and the fact that everything has been running so well for so long (about 60 years) is mind-boggling when one considers the modern technology unavailable to those workers in charge of constructing the dam and power plant way back then.

We were allowed to take photographs outside.  Here is the powerhouse building.

Here are the surge tanks.  They are "emergency" structures; if the gates into or out of the penstocks must be temporarily closed, the water already in them will surge upward into these tanks until the pressure equalizes.

The hydroelectricity produced at Garrison Dam is used across North Dakota and exported to several other states and provinces, as well.  (They have no way of storing electricity at the power plant, so they produce only as much electricity as they have been asked to provide for their customers' immediate needs.)

Abigail, Hillary, and Suzanna stand beside a turbine: it's seven feet high with a diameter of 18 feet.  A turbine rotates at 90 revolutions per minute, is spun around by the pressure of oncoming water from the penstocks, and turns a shaft connected to a rotor in a generator above it to create electricity.

Now it's time for our next destination . . .

1 comment:

  1. I know that I toured the Garrison Dam power plant when I was about Suzanna's age (as an activity at Girl Scout camp), but I really didn't remember anything we saw or learned as we were touring. Very interesting!