Hello,
My house is basically built in the water table. Therefore my french drains empty constantly into a bassin in my basement and is then pumped out to ditch. Unfortunately I can't divert french drains directly into ditch as my house is too low. I was wondering about installing a drywell with a sump pump that would be in the water table as well as being connected to frech drains. I would then connect a pipe from that sump pump to ditch. My question is since I want my french drains to empty in well, how far below french drains does the well have to be? I have to keep in mind that I will need continuious access to my well for sump pump maintenance. Would I need to double up the well in that case (one over the other) I'm looking at purchasing NDS drywell water leach system.

Thank you

Difficult situation for sure. But to try and at least partially answer your question and my experience is more in highway and bridge constuction---
But in highway underdrains (not culverts but rather piping designed to keep water from building up into the stone under the pavement) slopes as low as 1/2 of one % are often allowed in specifications. That would be as little as 1/16th inch per foot fall (1/4 inch drop in a four foot level) to maintain just about absolute minimum drainage from a point of discharge to a ditch flowline.
I don't totally understand your plan but sounds like a good pumping system is one of the few alternatives.

My house is basically built in the water table. In the water table or above it? How high above it are you because if you're not above it both the dry well and leach field will be under water. How deep the dry well will be will be determined by how far the run is, Figure 1/8th" to the foot slope. Can you give us more details on all the elevations? Here's a "do it yourself dry well". Back to you, Tom