100 year flood plain status

We are looking at a park that is in a 100 year flood plain, but the broker says:

“It has never flooded while the park has been there. The state has maintained the zone by putting in flood ditchs though out the zones.They review the zone yearly. The park is at the end of the zone.”

Based on this, it is not clear to me if the park is, or isn’t in the flood plain.

What should we do to determine the park’s flood plain status?

Any advice/pointers will be greatly appreciated.

Thank you.

Here is the link to the fema site where you can find the official flood maps. Just put the site address in


@PhillipMerrill, thanks Phillip!

I reviewed FEMA’s flood maps, and this particular area is “PORTIONS REMAIN IN THE SFHA.

It further says “STUDY UNDERWAY (This Additional Consideration applies to all properties in the LOMA-OAS DETERMINATION DOCUMENT (OUT AS SHOWN))
This determination is based on the flood data presently available. However, the Federal Emergency Management Agency is currently revising the National Flood Insurance Program (NFIP) map for the community. New flood data could be generated that may affect this property. When the new NFIP map is issued it will supersede this determination. The Federal requirement for the purchase of flood insurance will then be based on the newly revised NFIP map.”

This was back in January 2015. There has been no update since. Is there anything we can do to find out for sure if this MHP is at risk for flooding?


A few points: 1st the fema flood maps are notoriouslying inaccurate that’s why there is the Letter of Map Amendment (LOMA) process where you can amend the official map by hiring a surveyor to demonstrate that the map is incorrect and that a tax lot or a portion of a tax lot should not be in the flood plain. 2nd the maps are always in the process of being updated. 3rd by being in the flood plain most people are referring to the SFHA (special flood hazard area) the 100 year flood plain. Most people don’t really understand this it is a 1 percent chance of flooding every year. It could flood every year for the next 100 years and then not flood for the next 1000 years. My point is the odds reset every year 1%. The majority of the property I live on is in 100 yr flood plain it floods. It floods every other year more or less.

4th and most importantly if large portions of the property is in the SFHA it will be hard to get a loan, or flood insurance. I would not buy a park where the majority of it is in the SFHA.

If there is a LOMA for the park that would potentially change things.


As Phillip points out, the 1 percent chance storm is the key. You can only know if it is in the flood hazard zone by determining the elevation of the 100 year (1% chance) storm event, called the Base Flood Elevation (BFE.) This is then compared to the ground elevation directly adjacent to the improvements on the parcel.

It will probably be the case that portions of the property are in, and portions are out, depending on their elevation related to the BFE.

As an Engineer and Land Surveyor, If you want to send me the property location, I’d be glad to look at the maps for you and talk to you about the situation you’re in.


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Philip, when you mention that, “if large portions of the property is in the SFHA,” what percentage would be considered “large?” I’m in a similar situation with GJS, and appreciate the input so far.

If any of the property shows up on the map in the SFHA the whole property will need to be surveyed to determine ground truth verses the Base flood elevation on fema map. My guess is $2000 to $5000 depending on how far they have to bring the elevation reference in from (satellite can work to get elevation as well) and size of property. Talk to your bank and @KurtKelley for insurance feedback. If more than a couple homes are in the SFHA I think most banks are going to get scared away. If you still can stomach the risk owner financing is probably the only option. I think a lot of parks with the majority of the park in the flood plain that are for sale are just looking for a sucker with cash. There are a lot of different variables as to the real risk involved: river type, river slope, potential debris in river to act as battering ram, development up river changing flood plain characteristics… Will you be allowed to replace any homes in the flood plain if the are removed? Regional flood plain politics…

Be very careful

Forgot to mention the risks to private utilities: well contamination, septic drain field will be unusable as long as it is under water or the soil is saturated, lagoon may over top (this happens quite frequently with lots of rain not even a flood), you get the idea I’m not a fan of flood plainso and private utilities.

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I just got into escrow on a park and campground in NorCal. 37 MH sites, 36 campsites. 5 acres on a peninsula with awesome views. All sites are water front. Depressed county next to Sonapanoma, if you know what I mean (wine country). However, there is a Walmart nearby where the homeless hang out.
11 occupied sites plus 4 vacant POHs. Owner operator died. Space rent $390 plus utilities. Campsite $30/ night. On city sewer and water. Almost the entire 5 acres is in FEMA 100 yr flood zone. Any new homes need to be set 1 ft above flood level. The existing homes “have not been flooded.” This is on a natural lake, not a river. Park established 1969.
Heres my business plan:
Have property surveyed WRT Base Flood Elevation (BFE). See if existing homes are set above that or not.
Check with local MH dealers re selling some park models on site. Market to retirees, fishermen and vacationers. Accept RVs on month to month basis, same lot rent.
Get a campground host in for the season. Market on the Internet.
My accepted offer is at an 8 cap of current NOI of the MHs only, no consideration of campground income.
My main concern is in resale value in the flood plain. Will try for a LOMA (letter of map amendment) from FEMA but won’t be able to get this until after its a done deal. whadaya think? Value in CA dollars?
I love this area and come here often to my vacation home. I am nearing retirement and want some income other than social security and the stock market. I do not plan to get a bunch of MHPs. So a little different business model from many on this forum.

@Onthelake82 , as per your post:

  • “I just got into escrow on a park and campground in NorCal.”
  • “Almost the entire 5 acres is in the FEMA 100 yr flood zone.”
  • “Any new homes need to be set 1 ft above flood level.”

First of all “Congratulations” on your escrow!

As per your post your Business Plan is to have property surveyed for Base Flood Elevation (BFE) and see if existing homes are set above that or not.

As per your post your Business Plan is to check with local MH dealers regarding selling some park models on site.

In the past we had some acreage (in South Carolina) on a bluff on a river that was for sale.

We had a couple place an offer on the acreage and we agreed upon terms.

During the Buyer’s Due Diligence the couple contacted a Mobile Home manufacturer and built their “Dream Home” (with every “option”) on paper.

When they received their quote for the Mobile Home setup, they decided against purchasing the acreage.

Because the acreage was in a flood zone (even though the land was on a bluff that had not flooded), the setup required the following:

  • Earth Fill: Earth Fill to be added to the site to raise the Site Grade to or above BFE
  • /OR/
  • Foundation: A permanent foundation with reinforced pier system
  • Engineer: To review and sign off

The Buyers could have removed some of their Mobile Home “Options” and placed that money toward the setup. However, they selected not to do this.

Shortly after these Buyers decided not to go forward with the purchase, we received another Offer which we negotiated Terms and sold the acreage.

These new Buyers were very aware of the flood zone. These Buyers are saving their pennies to build their “Dream Home”. While they are saving, they come almost every weekend to the acreage; camp; and have a grand time.

For us we had acreage and we had Buyers that were willing to spend the “extra” money for setup /or/ a foundation based on the Flood Zone and BFE.

  • However, for a Mobile Home Park will you have Tenants willing to spend that extra money for setup? (How much is that extra money for setup?)

  • Or will you be willing to pay the extra money for setup?

  • Are the 4 Vacant POHs usable?

  • If usable, will the Power Company turn on Electric for you or will you have to get them inspected prior to the Electricity being turned on?

  • If inspected, will you be required to adhere to new standards for setup?

  • If adhere to new standards for setup, how much will it cost to raise these Mobile Homes to the correct heights?

We wish you the very best!

Kristin, thank you for your reply. I just visited the property today with the onsite manager. One side of the park did flood into the MHs 20 years ago. Many of the homes have been abandoned, slowly over the years due to rising rent, utilities and the recession. Many were used as vacation homes and when the recession hit folks just walked away.
The good: metered city water/sewer, electricity billed direct to homeowners by power co., garbage billed to homeowners. Simple straight asphalt road, small shade trees. Located on a beautiful natural lake where I have a vacation home, 2 hour drive from my home. Price 500K which is an 8 cap based on current NOI. 37 MH sites, 36 campsites.
The bad: Flood zone, depressed economy, high vacancy.
My new plan is to keep the existing MHs in the high areas, and gradually bring in long term RVs or Park Models to fill the low side, so these can be moved if flood occurs. I’m told that Park models are considered RVs, not requiring permits or the same setup as MHs. RVs are super popular here. The market here is retirees, fishermen and vacationers.
Then bring in electricity to half the campsites to make them attractive to short term RVers. I would bring in a campground host during the season to run the place.
This is a different business plan from Frank and Daves but theirs is hard to make work in CA where MHPs sell at a 5 cap with no upside. I have been looking for a year and this one inspires me. I will try to get the price down more when I finish my due diligence.
I wish you the very best, too.:smile:


Keith, the MHP’s address is:
29 S Outer Dr, Martinsville, IN 46151

Thank you very much for everybody’s feedback.

Thanks for the advice!

Hi Keith,

I’d love to ask you about a piece of property and the potential for flood. The property address is 7000 US 40, Kansas City MO. It looks to be completely in the 100 year flood plain. The highest and best use may not be a mobile home park, curious what your thoughts are. Call or email anytime, hope you’re having a great weekend! Will 831.706.6980 Noel@elkhorngroup.org