There's lots of approaches that will work and the drain tile is a prescriptive that I was told came up in the mid 20th century - however one of the rental properties we own actually has a wooden foundation, with extensive weather wrapping around it, and then about 2 feet of pebbles/river rock out from the foundation in each direction.I've found finding and tying into existing drain tile to be extremely problematic - (how deep is it, where is it?)

@Lap Ku, Great question - There's no prescriptive statutory period. 

Unfortunately trial and error is the best prescription I have found for finding the balance.

If forced to “legalize” it with permitting, either ask if they have “prescriptive measures” for deck framing you can review and see if it matches, or hire a Str Eng to investigate and draft a plan that matches the deck + any retrofitting they feel is necessary.

Here's an example of that, this is wood framing but just look for the enegy one. https://www.ladbs.org/docs/default-source/publications/information-bulletins/building-code/wood-frame-prescriptive-provisions-one-story-residential-construction-only-ib-p-bc2011-004.pdf?

I found that some of those sites, when used separately, offer nice features such as quick pre-scripted replies and prospect resumes sent right to your inbox from their first inquiry.

I understand easement by prescription.

Michael, very resourceful and clear response with prescriptive guidance - much appreciated!

You then find out the dirt road was put in years ago so that neighbor now claims to have a prescriptive easement. 

I would dig into a prescriptive easement.