French drain for a spring, but must cross driveway 2

[CrowChick]

My mother's house and yard is located in the valley formed by two crests on a mountain. Much water and streams come through this narrow passage, and the yard is prone to puddling in wet weather. To give you a view of the yard, imagine looking down a short driveway. One one side is a house and a rise. On the other side is a drop and progressively marshier ground consisting of springs, seeps and streams that flow into a larger stream at the base of another rise farther off. The soil is silty, and when the septic tank was installed, the excavators pulled out blue and white chunks of silty clay, indicating that some parts of the yard are constantly wet deep below the surface.

Now on the house side of the driveway, a great pool began to form in the rainy season, but it never dried up. In fact, the ground began to sink over time, whether from previously being used as the occasional turn-around for cars or from the water or from both. A spring on the other side of the drive had stopped flowing as well. Upon digging into the problem area, I found that the spring had relocated to the house-side of the drive way, backing up and causing the pool to run out across the driveway.

So we are installing a french drain, which will shut the water down the slope and help drain the yard of puddles as well. It will be made with 4 inch perforated black corrugated pipe surrounded by drainage stone and wrapped in landscaping cloth. However, the drain crosses under the driveway, and herein lies a problem: Do we continue with the french drain layout, two inches of gravel under perforated pipe, covered in gravel and wrapped in landscaping cloth, or should we use non-corrugated pipe and treat it more as a culvert to carry the water under the driveway? Any input would be most helpful. I hope I have made the situation clear enough. Thank you.

 

[oldestguy]

Sounds like a culvert is best for long run dependability, since you can maintain it better and occasional heavy rain will be handled more rapidly.

However, I am one to disagree with your underdrain design, even though others seem to be of different view. I base my opinion on many years of finding mistakes and problems with what you are proposing.

Go to Search above and use Search for Thread. Take a look at thread 171016 and make up your own mind on what is a good design.

None of my jobs has failed.

 

[GeoPaveTraffic]

It shouldn't really matter if you use solid or perferated pipe under the driveway. However, I too would modify the drain design. As oldestguy indicated, different drain designs have been debated herein in the past.

 

[cvg]

I would recommend solid under the driveway for a couple of reasons. 1) perf is required where you expect to be picking up water, you should not have as much infiltration through a properly designed and constructed roadway as you do in the surrounding un-compacted soil
2) perf pipe may also introduce water into surrounding soils which should be avoided under the road

 

[epongra2]

Based on your description, it sounds like the site is in the vicinity of a fault zone.

Is the leach field contributing to the high groundwater on the property?

 

[CrowChick]

Thanks, CVG. We used non-perforated under the driveway. My mother's instincts were right.