I had the same issue, however foundation was fine - it was digging extra 3 ft to put sewage pit, hit artesian. And it really depends on flow, ours was quite a bit...

What a mess. Yes install pit with powered pump, snake run lots of corrugated pipes under, attach them with clips (thick wire), turn on pump, put gravel, membrane, add thick concrete with hardner. Engineer is correct, they can put commercial buildings in water, however understand it will not be his basement when it floods 10,15 years later.

Move the garage. Or buy a new lot.

If there enough volume that the spring now flows out onto the land to create a small stream, you've got all kinds of headaches here, and not just water infiltration management ones. You will have to manage the flow off of the property where it doesn't impact any neighbors negatively. And, you might be subject to some wetlands regulations here if the flow is active at least 6 months out of the year.

My first inclination is GreenDesigns'. But, then, you've had an on-site visit by a qualified geo engineer, I presume.

AS mentioned above, the answer depends on the flow.

I hit water at one corner of an infill excavation where a walkup was put in, probably flowing one gallon per minute. Rather than installing a sump pump and pit, I used extra weepers and a stone storage reservoir for "heavy flow" days. Lived there for six years with an absolutely dry basement while the stream flowed away to the city storm sewer.

Same issue here. Our builder and foundation guy did a fabulous job of rerouting the spring and making sure our basement is dry with extensive drainage work. And a year later, the spring has dried up completely, and we have never had an issue with water in our basement. The water was rerouted to a pond on property next to ours that our builder owns. It actually enhanced the pond and has no negative impact to anyone. I'm not sure if the link below will work for you anymore, DH may have terminated that site. The pictures aren't in any order, just random pictures we took. Click on drainage and waterproofing.

Here is a link that might be useful: Pics of our drainage

Thank you all for the great information (and photos)!

Get it to drain to daylight with no pumping.