alignment direction

[Hidden_Brain]

I am looking to get some guidance on the direction of alignment for stream restoration projects. A co-worker of mine insists that alignment stationing be done from upstream to downstream per standard convention. I can think of two specific reasons, one technical and other construction related, why I would prefer to have stationing from downstream to upostream:

1. hydraulic modeling will be involved, most cases it will be HEC-RAS used, that reads flow direction from higher station to lower station. so now if stream is stationed per "standard convention", very easy to confuse the c#*p out of people understanding relation between HEC-RAS stationing (for permits) and construction stationing (for design and construction). please note that I am aware that you can set up expressions for stations labels to show both in plans.

2. I am a no-expert in costruction, but would imagine if the stationing be done from downstream to upstream, then-

   a) plan can have a note stating that all channel construction to proceed from downstream to upstream (from 0+00 and increasing station). in this way, water will always have a flow out for heavy rainfall events during construction, which would otherwise, get stuck and pond.

    b) if earthwork is involved within channel, contractor probably would submit earthwork estimates for each pay period to get paid. if  stationing is from upstream to downstream, and plan note states contractor to start downstream and proceed upstream, now the contractor has to do all the math (no disrespect meant, they have a tough job, maybe would like to make it easier). if the stationing is from downstream to upstream, easy enough to know the lineage and earthwork calculations of the work already done.

I have the same question for drainage networks, which again, I am inclined to adopt downstream to upstream stationing (profile views) and construction to avoid ponding/flooding. I hope what I said above makes some sense. looking for people to share their thoughts on adopting the way that makes more sense. any thoughts shared are much appreciated.

[Joe-Bouza]

Why do you feel compelled to state means an method for this type work?

[Hidden_Brain]

Joe, I am not sure, that is why I am seeking advice. what happens if the site gets flooded because the contractor started construction from upstream to downstream, and now the water has nowhere to go?

[Anonymous]

As far as i am aware, Rivers chainage convention is upstream to downstream with sections taken looking downstream. I'm sure if people involved are doing this kind of work regurely, they'll be used to the difficulties that arise from it. However i'm all for challenging usual convention, so if you can prove that this will save time and effort, go for it. However these conventions normally come about for good reason.

[Anonymous]

Project staging should be covered in the construction methodology!

[Joe-Bouza]

When you make a plan you expect competent people will be bidding to get the job.
You can demand staging plans ans schedules in the the spec prior to commencing work., but the more you (the engineer) try to govern means and method - you are buying the liability that goes with it. I agree we want the project to be safe for the everyone, but the contractor is puttin his bond on the line.

demand schedules and review and have daily progrees / coordination meets to monitor whats going on. thats my advice