Last Thursday, Yukon Energy held an information night at the boat locks at the Marsh Lake Control Structure, a.k.a. the Lewes Dam or Marsh Lake Dam, on the Alaska Highway a few miles east of Whitehorse. The purpose was simply to show people how to use the locks. Although basically very simple, there’s one little aspect that apparently gives some people trouble and sometimes causes damage to the locks when they force the lock doors open.
Let’s pretend that we’re going upriver. We’ve run our boat into the lock and climbed up top. Close one downriver door…
…then close the other downriver door. To keep things as simple as possible, there’s no assistance – no button that closes both doors at the same time hydraulically.
There’s little difference in the water levels above and below the dam right now – less than a foot – but the next step is a very important one even with that little a differential.
The wheel that Ron has one hand on is a valve that MUST be opened to let the higher upriver water into the lock. Only once the water pressure has equalized can the upriver doors be opened easily.
Then you simply open the upriver doors, climb back down into your boat and sail out.
There are clear instructions mounted at the lock. There used to be two sets of these signs but one was destroyed by vandals a few months ago. The level of vandalism here is appalling – thousands of dollars are spent every year keeping the locks operational.
When anything wasn’t clear, one of the Yukon Energy staff was happy to go over it again.
A barbecue had been set up on the tailgate of the Yukon Energy pickup, and we were soon enjoying a picnic with all of our new friends.
Huge thanks to Yukon Energy, and specifically Ron Kirkwood, Melanie Pettefer and Darrell Johnson, for hosting this event. Great shoes, Melanie! 🙂
Finally, here’s a video of the whole process of getting your boat through the locks. Have fun!
The dam has a long and interesting history which you can read about and see photos of at the Exploring the Lewes Dam page on my blog. I spend a fair bit of time around the dam – as well the good vibe it has for me, it offers excellent hiking and photography on the cliffs above.