Sunday, February 22, 2009

Training water...

It's that time of year again. Err... right. Not quite. Mrs. Spit would tell you that it's not a particular time of year, it's any time of year. Time for Mr. Spit to be sent off to the middle of some remote part of the province for his job.

This time it's a venture into hydraulic engineering. In the business, what we're doing is "river training" and it's not quite as exotic as it sounds.

Unlike my dogs - well, maybe the Collie, the Mastiff is more 'willful' and not as willing to accept direction - you can't really "train" water. However, it can be directed. When we create structures in a watercourse (i.e. a creek, stream, or river) to cause the flow to be directed to flow where we want it to, instead of where it is tending to do so naturally, we are in essence, training the river.

The project I'm dealing with right now came about as a result of the river deciding (pardon the anthropomorphizing) to leave its normal path and carve out a new path. The problem is that it happened right at the location of a bridge carrying a highway. As you can see in the photo below, this resulted in a long stretch of vertical banks, as the river moved further east and eroded the east bank.

If the river can't be brought back into a more disciplined flow pattern, ultimately it would wash out the road behind the east abutment to the bridge - not generally a good thing.

As a result, we are going to be installing two structures at this site. Upstream we will be placing a small spur, while closer to the bridge we will be building a large guide bank. The spur will take the energy of the river and direct it away from the bank. Then, as the river approaches the bridge abutment, the guide bank will guide the flow around the abutment to ensure that it both flows under the bridge and does not erode the bank further.

More to follow...

1 comment:

Heidi said...

That sounds like a very interesting job! I can't wait to hear more about it!