Discussions

(Making this separate to not hijack the storm related thread)  
 
Every time they close the dike I have to wonder why it was designed that way. From my uniformed view, I would think that running the dike beside the road as it slowly raises to a height where it can go over the top may have been a better solution. I totally get that at the time it would have been much more expensive, but these repetitive emergency "close the dike" jobs can't be cheap either.  
 
So my question... Is there a reason from an engineering standpoint for going the "temporary as needed" route? This is an honest question, not trying to armchair quarterback here, have just always wondered.

this is a picture of that same grand valley road dike during the flood in 2011 when it was built. If you build the dike roadside the water would have been way higher and it was it limits as it was.

Options have been considered in the past, most options had the grand valley road connecting with 18th street around the lights that enter the corral center. Every big flood this topic comes up. To be honest it’s doable and may get re routed in future. From an engineering standpoint there shouldn’t be much of an issue beyond through truck traffic going east/west would then have two extra turns and they all require large turning radii, this may actually be a big concern to M.I. but not sure. I think the cost to plug it is the City if Brandon’s cost, but west of 18th I think M.I. controls the roadway so it might not be a priority.

Thanks for the answers, but I don't think either understood my question. Not moving the road, just raising it slowly so it forms part of the dike and then drops again. I'm including a crude diagram as an example.  
 
I'm thinking mostly cost would be the issue, but is their an issue from an engineering perspective? Like, would it be weaker than the temporary that goes up 3 or 4 times a decade now?  
 
I guess one advantage of the current setup is that no one can drive around a roadblock and get onto the flooded portion.  
 
Edit: @Clubman... I totally remember those super sandbag dikes. I avoided going near that end of town!  
 
Edited by RantsFromWinnipeg, 2020-07-02 19:11:02

i don't know what the purpose behind that scenario would be? Look how far back the flood waters go you would need to raise the road entirely not just gradually right before the intersection. Then at the intersection it was like 9 feet deep there so a gradual wouldn't work without raising 18th up quite a bit to connect. I think moving the road further north to the coral center would be the best option. Both options would be costly.

I believe this was one of the options considered in previous years along with the many other options that moved the road north. I remember seeing atleast half a dozen various options that either kept the road high and dry or others like yours that simply solve the plugging of dike option but that doesn’t keep the road to the west open when water goes over top of roadway. In concept your sketch would work fine but the length of roadway that would require to raised is a lot more then what you have shown, probably closer to double or triple the length due to traffic sight lines and safety. This is a fairly new issue as it’s only been closed off a few times ever. It’s simply not a priority yet. For now I think it goes back to what I stated earlier, it’s a city cost to plug it and it’s an MI road to west, it’s simply not a priority for both parties yet. I think M.I. has more important projects to complete that has been on their “to-do” list for a lot longer.

drawing has 3 areas of possible over topping or failure. While the current design has the one point. With the current plug design it can be quickly made higher with less risk. Either way, that road gets flooded over and closed.

Yes, I totally wouldn't be surprised if it would have to be much longer for sight lines, I did say the diagram was crude!!  
 
@ Trevor B: I can see your point about more failure points, my only question is what is more apt to fail, a temporary dike made in a week or so, or a permanent structure built over months? If both are about equal, with the money savings in the short term, I suppose it would take a lot of closings to get to the cost of the other.  
 
In the long run I guess I wouldn't be surprised if a major redo of PTH10/18th ends up raised to the dike level so that the highway is the dike, with Kirkaldy, Grand Valley Road, and the Corral Centre entrance brought up to meet the new road grade level.

I think that the best solution would be to raise 18th Street from the bridge to the hill going north to the level of the sand bags.  
Raising that stretch of the street would be the best in the long run as you would never have to worry about blocking traffic to fill in the dike, it would be permanent! The access streets would have to be sloped back to access the new incline but there would be no disruption in traffic or business after it was done.  
They have brought in clay and dirt 3 times now to fill that area and it just seems to be throwing money into the wind and not solving the problem.  
Spend the money and do it right like they did with the bridges instead of putting a bandaid on things.  
Yes the cost of this would be high but it would be a permanent fix.

it is after all a road built on a flood plain right beside a major river. The north-south dike is protecting everything to the east that is built on a flood plain right beside a major river.  
I personally think "the plug" is the best option. Quick and easy.

yes raising 18th would be the best long term option. We are currently on new "bridges" money list right now, so i'm sure raising 18th is many years down on the list of lists.

raise all of 18th and the access roads would be quite expensive and a challenge with all of the current infrastructure and businesses in place. Hindsight is always 20/20.  
 
Also as to building in a flood plain while right now with all the other methods of transportation it seems stupid, but back when the river was the main and sometimes only source of transportation, communities were built along them. People also build in areas of tornadoes, hurricanes, earthquakes, volcanoes and other natural disasters everywhere.  
 
And with the situation we are dealing with now came from a few nasty of the nasty thunderstorms. We've all have storms with heavy downpours before.

Here's the thing, when they started building there in the modern times it was already known that the floodplain shouldn't be developed. From what I understand there was a time when all the properties in that area were bought up and removed. There was never supposed to be development there. But like anything, time moves on and societal memory fades.  
 
Allowing the building of that mall in that location will probably go down as one of the largest blunders in the history of city council.  
 
Frankly, the number of times that Walmart has flooded I could see a future where they don't renew the lease and build on higher ground.

Needs to visit East Grand Forks North Dakota.  
The plug as we know them are built like huge interlocking cement fence sections.  
In spring the panels are lowered into place with rubber seals between them by a crane and simply lifted out and stored when the threat is over.  
This happens in several places around the city and is a proven solution.