Underground Spring 2

[cieg22]

An architect approached me about a home addition. The homeowners believe that there is an underground spring running through the area where they want to build.

I'm a lowly civil engineer, and I realize that ultimately we will need to get a geotech involved. For now, I just hope to gain a rough understanding of what this might entail - how would you go about determining whether or not a spring is present, its path, scale, etc? I assume it would involve piezometers, borings and an investigation of any connecting stream, but that's about the limit of my knowledge.

Thanks everyone for your help.

 

[msquared48]

Does it show at the surface?

Is it seasonal or year around?

What does the topo indicate?

Do any clay or impenetrable lenses show at any outcroppings or cuts?

Could a cut-off trench suffice control the problem? French Drain?

Away from the spring, what is the infiltration like? Any?


Mike McCann
MMC Engineering

 

[cieg22]

These are all great questions! I don't know anything about the site yet - once I get the info, I'll definitely post it.
Thanks for such a quick response.

 

[Patgeotech]

cieg22,
Just recently we encountered dry springs that were in weathered granite - at the time the instruction was given to fill in these dry spring 'holes' - the contractor did not do it and the springs were recharged by unseasonal rain events. We managed to contain one spring by connected it to underground storage tanks (client has an endless supply of clean spring water), with overflow facility (water feature in garden). Our troubles did not stop there, as we found out that there were several other springs all interconnected by jointing in the granite. We installed numerous subsurface drains and managed to guide/redirect the spring into the drain system. Not an easy undertaking on site as we had to use localised sump dewatering measures to get the pipes laid.

Depending on the conditions, whether the spring is acessible, we have managed to add a dye to the spring and noted where the dye appeared - can be a good indicator depending on the site conditions.

Be careful with the boring option, one can miss the spring altogether and get a false impression. Get a local geotech involved.

Good Luck!

 

[fattdad]

There is not an undergound spring beneath the house lot. A spring is something that daylights at the surface - when the hydraulic grade line is higher then the ground.

Is there ground water flow beneath the site? Likely. Is it a potential problem? Who knows. Are you planning on any deep excavations, basements or the like? Maybe then it's relavent. Otherwise, I'd like to know more about the homeowner's concern. It can't just be some thought that there is ground water flowing under the land, could it?

f-d

¡papá gordo ain’t no madre flaca!