Big lock on a big river

Jaq and I had a trip out recently to the Lower Granite Dam on the Lower Snake River. The dam is 2,655 feet wide and stands 254ft high. It has 6 generators that produce 810MW of power. There are 4 dams on the
Lower Snake River all generating power and a further 4 when it joins the Columbia on its way to Portland and the Pacific. Behind the Granite dam lies a lake of water stretching 39 miles.

The dam has a single lock, the bottom gates can be seen in the pic above, that measures 674ft by 86ft wide with a 100` drop. Now i`m not sure if they class that as a double or single lock but taking a Narrow Boat of 60ft my guess is you can get 132 boats in facing forward with room at one end for perhaps 2 across the lock.

Above is the inside of the lock, 46 million galls and 10mins to empty/fill. Besides pleasure craft barges use the lock and typical cargoes would be Wheat, Barley, Petroleum, Machinery.

This is a typical tug and 4 barge set up.It is the equivalent to 280 rail truck or 1,076 USsemi / UKartic loads.


The fish are guided into fish ladders that are like the exhibit in the visitor centre below. Fish make their way along an uphill channel with laybys that give them a refuge to rest before swimming on and upwards.

Watching fish use the ladder from inside the visitor centre.

I would love to have gone on the guided tour of the dam that included the power house but the whole site is run by the US Army Corps of Engineers and US citizenship with photo id is a condition of a place on the tour. Jaq and I even had to show photo id just to drive the road across the dam, luckily they accepted my UK drivers licence but warned us not to stop till we reached security on the other side. I stood up with my head through the sun roof  to get the lock picture.

So a rare chance to walk along by the river and past the Marina but the warning signs tended to make me not stray to far off the tarmac.