Chris, the thirty day notice of ending the month to month is pretty standard, but you could give the tenants a chance to apply (your application) and if approved, use a lease (your terms) and explain you did survey the market and found them 200-300 hundred under...

I'm letting it go if the survey shows that setbacks are adequate for the house. 

The problem is that there is a flood zone along this creek and it only impacts 5 or 6 houses, so none of my comps are in the zone.Of course, I would get an elevation survey to see if the structure was actually in the zone, but I am pretty certain it is.

I did find sandbags locally and a friend and I did some surveying and figured out how to keep the water moving and not running into the basement.

Some areas, typically more rural areas, will use a "meets and bounds" survey that says "starting at the SW corner of the NW quarter section of section 14, township 3, range 5, north 100', then north 93 degrees west 300', blah de blah".

There are surveys published fairly frequently that give actual returns.

It may require getting a survey done to determine this (the current owner may have one). 

Have your agent check them as well- check to see if there is a survey of the property to determine the elevation of the lowest floor. 

Aside from sales charge and attorney fee,  seller’s closing costs in this area are: title search (800) survey (400) transfer deed ($9 per $1,000 of sale or $4 per 1,000 depending on County/exemption status).

Over the course of the last 10 years I've performed dozens of Phase 1 and 2's as well as Environmental Baseline Surveys, Condition of Property Assessments, an EIS or two and would love to help clear up any confusion you may have...or at a minimum get you pointed in the right direction.