Need to hire a geotech engineer in south-central Indiana

[IndianaDam]

Where can someone hire a geotechnical engineer for a small project involving a dam in south-central Indiana? The dam is shown in the following video:

https://www.youtube.com/watch?v=uCEGOUn8hbA

I've been quoted $65K to $85K by a commercial geotech engineering firm in Indiana for the following:

Surveying (topographical)
Geotechnical drilling
Sampling
Laboratory testing
Geotechnical engineering evaluation
Geotechnical recommendations
Report
Basic construction drawings

I'm not sure if this quote is reasonable and if I need all of that, but assuming it is reasonable, I wonder if there's any way I can get the cost down?

Back story: I purchased a property in 2022. The seller had a dam failure in 2020 but did not mention it to me. He patched it up with rip rap. The dam started sliding down in 2022. I patched it up with more rip rap and clay on top, which of course made things worse with more weight.

 

[dik]

If legal stuff, talk to a lawyer first. Let the geotekkie know that it is a legal issue. I don't do legal stuff anymore but my charge out rate was typically 3x my normal fee.

-----*****-----
So strange to see the singularity approaching while the entire planet is rapidly turning into a hellscape. -John Coates

-Dik

 

[IndianaDam]

No, not a legal case, I guarantee that. past the statute of limitations. Paying out of pocket.

 

[GeoEnvGuy]

You could ask the firm that quoted to let you know who else could provide the same service, or if they know of any old engineers that are a one man show that can do the same job which would be cheaper. Likely going to be a similar approach on the work to be done, largest expense is the investigation and watched the video not sure if drilling is the best way so you might ask them to look at test pits which would be slightly cheaper.

For the overall project cost any solution is likely going to include foundation preparation, may require dewatering the pond, fill materials hauled and compacted, this cost is likely in the 6 figures.

 

[LittleInch]

Can't you just drain the dam?

That doesn't look like rip rap to me, but stone?

No good outcome here.

Or ask them for an initial assessment report and desktop report to break it down into bite sized chunks. It looks unrepairable to me at any sort of cost benefit.

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[IndianaDam]

I spoke with the geotech engineer today. It sounds like the biggest cost is drilling the 10 or 15 six inch diameter holes for samples, testing the samples, and a host of other things. The goetech engineer and a civil engineer (who has dam experience) would then provide a plan. I'm expecting a formal proposal in the coming days. The reconstruction might cost 60-80K as well, so a $160,000 project. This is double what I was expecting, but I suppose there are projects that are even more expensive especailly if DNR gets involved.

My brother who is not an engineer, but is in construction, thinks this might be repaired by making a gigantic (although ugly) retaining wall out of 18" concrete pylons drilled down 15 feet and pumped full of rebar/fiber reinforced concrete every 4 foot across with huge barrier blocks sitting on top of each pylon, tilted inward, going up about 6 courses (like a retaining wall). My concern would be dying in the process of working on that due to the dam failing, even with the lake/pond pumped out. The pitch of the dam is crazy steep and it is soft at the tow.

 

[LittleInch]

Sounds to me like you need to drain this dam fast before it fails.

Even doing test boring can precipitate failure.

Soft toe indicates a dam about to fall without further warning. This structure is screaming at you that it's about to fail. Really not sure why you're not listening??

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Also: If you get a response it's polite to respond to it.

 

[IndianaDam]

Not sure what you mean by not listening. I've had geotech engineers out and a large Harbor Freight trash pump running 24/7. Indeed it is about to fail.

 

[LittleInch]

Good. You didn't tell us that bit.

So why do you want to do this geotech work if the dam basically needs rebuilding?

Is there no authority that needs to be told the condition of this dam?


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Also: If you get a response it's polite to respond to it.

 

[IndianaDam]

I had an excavation company come out, they saw the grade and how close to the property line the dam was, and told me to call a civil engineer. I called a few, they all told me to call a geotech engineer. Three referred the same geotech firm well known in the area. The geotech came out and said he could do a study and plans ($60-80K) so a construction company could follow it. Before I knew it, my $50K dam repair is looking like $160K or more and I'm not sure if I need a geotech engineer. Still wondering if my brother's "retaining wall" idea might keep costs down and make it where I don't have to move the dam inward and make the lake (large pond) even smaller. The geotech said no authority needs to get involved, as it's around 2 acres and just under the limit for DNR to get involved. I do a lot of dirt work on smaller equipment, and I was tempted to try to fix it myself, but I've heard of people getting killed fixing dams (a guy in Kentucky recently got killed), and with the tow so loose and damp, I'd be in over my head. No pun intended.

 

[LittleInch]

Normally you do GI to tell you things you don't know or need to know in order to undertake design work.

You know the dam wall is falling and needs to be replaced in entirety at a lower slope angle.

Retaining walls are not simple and then you do need to know what's in the ground underneath and get a proper design.

What is this water body there for?

Is there no means of draining it by gravity flow?

You could always syphon it to get the level down.

Remember - More details = better answers
Also: If you get a response it's polite to respond to it.

 

[IndianaDam]

It's a recreational pond/lake. Yes, it could be drained by gravity, if I had a long enough hose. I should get a longer hose from harbor freight so I'm not running my trash pump to death. But it's getting it down about 6" a day and there's no rain in the forecast for the next two weeks. Sounds like I need a new excavation company that does not require an engineer, and may have to move it back into the property about 6 or 8 feet to reduce the slope angle, among other things.

 

[LittleInch]

You could do worse than Google " dam design manual

Your GI work could identify the layers underneath. Soft toe either means there is no key into the existing soil, or is getting underneath that or your drainage system is poor or non existent. Slope angles typical 2:1 or better

l "

A couple from USACE, and international organisations might be good bedtime reading...

Remember - More details = better answers
Also: If you get a response it's polite to respond to it.

 

[zelgar]

Here's some information you should review from Indiana's DNR's site:

https://www.in.gov/dnr/water/dams-and-levees/

 

[IndianaDam]

Thanks for all the help. Will post updates.

 

[LittleInch]

Please do. It's always good to know how something turned out. Especially with pictures....

Hope we weren't too hard on you...

Remember - More details = better answers
Also: If you get a response it's polite to respond to it.

 

[GeoEnvGuy]

Still wondering if my brother's "retaining wall" idea might keep costs down and make it where I don't have to move the dam inward and make the lake (large pond) even smaller.

Sounds like a bad idea to me, but you can ask the geotech what they think about a retaining wall or secant pile or sheet pile wall solution and if could be more cost effective. The geotech that came out to site should be able to highlight the positives and negatives of other solutions. Don't like the idea of embedding a retaining wall footing at the toe of the dam due to safety concerns, and a concrete secant pile or sheet pile wall likely will not be cheaper.

 

[IndianaDam]

There's a new problem. The property line can't be accurately determined. There's going to be a margin of error of about 20 to 40 feet. Something about different township sections, the fact the neighbor's property starts at the Northeast corner and mine starts at the Southwest, and something about the description according to the courthouse (not sure what he was referring to). This dam is super close to the property line.

I don't want to kill myself at the bottom of the dam in an attempt to save money. $80K to $160K or more is a lot of money to me, but dying would be worse. I'm learning at least, so I can make a self determination on who needs to be involved. While I'm no engineer, rotational slide/slump slide with multiple ruptures and scarps are things I never knew about. I also thought about sheet piles but didn't know what those were called until now, and didn't know there was a name for "secant pile" that my brother sort of described.

Given the property line, sheet piles seem interesting. I will bring that up with the goetech. Still waiting on a detailed proposal from him.

 

[LittleInch]

I don't know what's downstream of you or what thejmlact would be of a sudden failure, but it might be a good idea to find out or try and work out so you can see what might happen. I suspect any damage will be on you as your insurance company might not be helpful...

Actually is there insurance on this?

Remember - More details = better answers
Also: If you get a response it's polite to respond to it.