MMD are things okay with you.

[whb]

Just heard that there were several people evacuated from floods in your neck of the woods.

Hoping for the best.

Howard

[mmd]

Thanks for your concern, Howard. Everything is OK so far. We have had a pretty strong "January thaw" in the past couple of days, culminating in a heavy rainstorm. The combination of meltwater and rain runoff raised the river level quite a bit, driving all the river ice from the fast-flowing areas west into town where it piles up on a natural constriction in the riverbanks. This is, of course, where the two bridges that span the river and give the town its' name are located. The ice forms a dam that impedes the flow of the river and the water backs up behind the ice dam and goes around the ice along Lahave Street. Although a rare occurance - last time was in 1970 and took a span of the old bridge out - the media is making it out to be more dangerous than it really is. Property is certainly at risk and smooth flow of traffic is impaired, but there are only six families in threatened properties and they have been moved to safer locales. The area under assault is mostly commercial, and of that mostly parking lots. The big concern is the bridges, especially the old one, built in the year the town incorporated, 1899. Also a concern is the shopping mall at the downstream foot of the old bridge - if the span fails on that side, the resulting wave of car-sized ice blocks could do some pretty serious damage to the Zeller's department store. Damned mall shouldn't have been built there in the first place! I was downtown at suppertime tonight and a significant portion of the ice dam (about 700 feet, or 50,000 tons) slipped under the lower, old, bridge, but there is a stretch of river about 1500 feet long above the bridge that needs to clear. The critical time is about now, when the high tide (the town is at the head of the tide in the river) begins to drop, increasing the load on the bridges. I haven't heard anything to the contrary, so I'm assuming that they have survived. One of the trusses of the old bridge has been reportedly bent during the tidal ebb this afternoon, but hopefully nothing further has occurred.

Some pictures are posted on the local IP server here: http://www.tallships.ca/ice.htm

[Peter Malcolm Jardine]

Ahhh Michael you have higher ground... thats good.. that ice looks threatening to that bridge :eek:

[mmd]

Yes, Peter, I live my days at about 80 metres elevation - the last time there was an ice dam in my back yard was when mastodons were cavorting in the meadow across the road rather than the present deer.

(edited for dyslexic fingers)

[ 02-04-2003, 12:21 AM: Message edited by: mmd ]

[Alan D. Hyde]

Do they still dynamite ice dams on occasion???

Alan

[mmd]

Yes, Alan, they do, but it is not an option here. To be effective the charge has to be quite substantial, and usually placed on the downstream side of the ice dam. In our case, such a charge would damage the bridge and, as the ice jam is in the middle of the business district, the damage to nearby buildings (think lots of plate glass) would be prohibitive.

[whb]

Michael,

Glad to hear things are okay. This is a strange winter. We have hardly had any snow or cold (relatively speaking) and the river is still open much of the way through town.

Howard

[mmd]

Just an update on the Lahave River situation - still icy, but pressure is somewhat relieved so the Bridgewater bridges aren't falling down. Old bridge remains closed until ice clears and engineers can do inspection. Turned really cold overnight, so the jam may freeze in place. That will merely prolong the emergency. Some pics I took yesterday:

A house upstream from the bridges suffered damage due to ice pans invading property during high tide.
http://www.imagestation.com/picture/sraid50/pe7c90f95775328cb1f83b9b11febc79b/fcad0bdf.jpg

An excavator attempts to remove some of the ice threatening the shopping mall. The parkades on the opposite side of the river are in danger of having their pilings torn away, as well.
http://www.imagestation.com/picture/sraid50/pf78a5156c4f75565aecc66563333e859/fcad0bd2.jpg

The north side of Old Bridge with ice jammed into structure. Water level is usually two meters below trusses.
http://www.imagestation.com/picture/sraid50/p43829105ba7bb1fcd2d2f24a7f14c9e6/fcad0bc7.jpg

A view of the south (downstream) side of the Old Bridge.
http://www.imagestation.com/picture/sraid50/p437b22f3feae29baf6262508e95c4834/fcad0b7a.jpg

[Alan D. Hyde]

Thanks, mmd.

We ignore the inexorable powers of nature at our peril.

Alan

[mmd]

For those of you who have had your interest in our little town's big troubles with ice piqued , Joe Mailman (the webmaster at Tallships & a buddy for many years) has posted a sequence of pictures of the ice jam on the Tallships website. Go to www.tallships.ca (http://www.tallships.ca) and click on "Bridgewater Ice Pictures".

The old bridge opened at noon today, having passed inspection by the Dept. of Transport engineers, but most of the ice jam remains. Over the past week they have removed enough of the downstream ice so that the remaining ice is now floating and water can escape under it. The water level upstream has dropped about 1.5m (5 ft) in the past 24 hours.

What remains is likely to be there for the rest of the winter. We've had about 30cm (12 in.) of new snow in the last 48 hours, and are expecting that again on Saturday. It remains very cold ( -20 C., -4 F.) so a repeat of the crisis if we have another sudden thaw is quite possible.

Interesting times, indeed.

[Alan D. Hyde]

I have heard stories as a boy from old loggers about their going out on log-jams in their spiked boots with pikes and peaveys, and breaking jams loose. Exciting and dangerous work, but both they and their employers viewed things with, it seems, a certain amount of fatalism.

One guy told me a story, of which he was the hero, about an ice-jam being broken up that way.

Was he just "yarning," or was that actually done, to your knowledge?

Alan

[mmd]

If the jam wasn't too tight or frozen in place, I think it would be feasable, but it would be brutal, dangerous work. If one were to slip off the slippery, semi-floating, moving pool table-size ice cake into the water one would expire from hypothermia in about three minutes if you didn't get caught under the moving ice pans and drown or get crushed between several tonnes of shifting ice. The leading edge of an ice jam is pretty violent when it starts to move, and pretty treacherous when at rest.

[Alan D. Hyde]

Thanks, mmd.

It's not somewhere I'd wish to go.

But the man who told that story had done many remarkable things in his youth, when he thought he was bulletproof. And he lived to a ripe old age, too. Part skill, part luck...

Alan