View Full Version : How do you avoid flood-prone property?

Aug. 19, 2011, 06:52 PM
All the rain lately reminded me how lucky we are that the current house/land doesn't flood or have damp problems. But now I wonder how you avoid flooding issues in land purchases. With houses, at least, all you need to do is open the cellar door and you have a hint. With a farm, though, how do you know if the fields become bogs every time it rains? Obviously, if there's a stand of cattails in the field, or a creek running past the garage, you know there's water nearby. But there are places around here that if I wasn't from around here, I'd have no idea how badly water collects in X spot. We have a lot of wooded areas that become wooded ponds in rainy season, or where the ground just doesn't dry out except in droughts.

Aug. 19, 2011, 07:01 PM
When I was actively looking to purchase my place, I went looking in the pouring down rain and when it had been raining for days. I also avoided lands that had trees and plants that were notorious for needing a lot of water.

Aug. 19, 2011, 07:02 PM
FEMA has flood maps that the public can look at. Just do a google search. The lower the number of years, the more often the area floods ie a 10 yr event occurs more often than a 100 yr event. Hope this helps.

Aug. 19, 2011, 07:10 PM
Flood plain maps.
Soil type.
Visit after heavy rains.
Look at indigenous plants.

Aug. 19, 2011, 07:41 PM
Ask the seller, not the seller's agent, directly. Most states have laws requiring the seller to disclose known faults.

Aug. 19, 2011, 07:44 PM
FEMA has flood maps that the public can look at. Just do a google search. The lower the number of years, the more often the area floods ie a 10 yr event occurs more often than a 100 yr event. Hope this helps.

also ask the neighbors;)

Aug. 19, 2011, 08:45 PM
I think (but not 100% sure) this has to be disclosed by the seller/seller's agent.

Aug. 19, 2011, 08:46 PM
Ask the local ag extension office. There is a wealth of information and knowledge on how to decode that info within those offices.

They are your tax dollars at work!!


Aug. 19, 2011, 09:02 PM

Google maps ... terrain feature

Aug. 19, 2011, 09:56 PM
Do digging through the old flood plain maps. Be aware of where even the 100 and 500 year flood plains might be. This is public information, but I can't remember which government office you'd go to in order to see them.

Walk the property well. Be attentive to springs or creeks and the proximity to the house. Is there a high water table, especially near the building site? Be very attentive to soil type, especially around the house. Look for wetland signs on the property (eg. wetland plant growth, naturally mucky area) as well as official wetlands on your property map.

Visit the property as a big rainstorm ends. Where does the water run to? Does water come from adjacent lots onto the property? Do you have any drainage easements?

And when you're ready to build, you can do things to maximize success: getting a good grade around the house. Have a french drain put around the inside of the basement. Make sure water coming out of rain gutters travels away & down the grading. Talk to the contractor about what kind of waterproofing they might be using to the exterior of the basement walls.

Aug. 19, 2011, 10:34 PM
There is flooding and there is water, which are different issues. Our farm, for instance, will never flood in a way that would show up on a flood map--it is on top of a hill for the most part and far from any bodies of water. But there is about a two week stretch where I have a small river running through it when the snow pack melts. I would not want to build anything near there (or locate my horse cemetery there). Much harder to get that info until you have lived there.

Site all projects well, and preferably don't build new stuff until you have lived there a while and know the little surprises. You can usually see water damage on existing structures when shopping but those seasonal things are harder to spot if, like mine, they are 3 inches deep over the grass and 100 feet across. They don't leave a gully you might know for water trouble.

Mine is not really a problem since I can just shut the gate to that field for a couple of weeks, but it could have been if I relied on access through there.

Aug. 19, 2011, 10:34 PM
Well, flood plains help you determine if a property will flood due to waterways.
Drainage issues help you figure out if your property will flood due to rain/not enough drainage.
If the property isn't in an actual flood plain, the flood plain map won't tell you much of anything.

I do recommend contacting your local ag extension.

Also check soil types, topography and if possible visit after heavy/long rains (or during and watch run off) to see if there's pooling and/or erosion and where it is.
In spring and summer check plant types and watch for water plants.
If you know someone in major landscaping/contractor then bring them along on any property you're really interested in. Most are really good at walking a property and spotting things that may be issues. (identifying plants, soil types, roll of the land, etc)

In my area of CT, the issue isn't flooding as much as it is drainage. We have ledge, lots of it. So despite the heavy woods and root systems...little boggy areas and wetlands are pretty common. My property is the highest elevation around me, I can't actually flood. No streams, rivers, ponds, etc nearby. Lotta ledge and a mix of soil types. (couple feet organic, underneath that here is a few feet of clay/sand mix...at least where there isn't ledge or enormous chunks of granite)
My issue is even after being dry for a long time...parts of my property can get a bit damp. All from underground water. I have a steady strong stream of it under/around my riding ring. Took a massive curtain drain all the way aroound it (3-8' deep depending) to redirect it away. And all buildings were built up with higher foundations and all land sloping away from all sides of each building for run-off flood prevention. I have a ditch around my grass paddock to redirect road run off. But in spring I have so much excess underground water there that I get bubblers...little fountains that spontaneously appear, LOL! That's only for a couple weeks though. :D

Aug. 19, 2011, 11:03 PM
With the weird weather we've been having. Ideas of Global warming and the breaking up of the Arctic ice pack.

ANY land might become flood prone in the not too distant future. :eek:

Otherwise I'd ask the neighbors and local farmers.

Aug. 20, 2011, 12:33 PM
What you do to a house determines if it floods also. Bad grading, not routing water away from the foundation, and previous hidden water problems make a difference also.

For example, the house next to mine in Colorado had the entire back yard slope toward the house, the owner cut the downspout extension off so he wouldn't have to move it for mowing, and the grading near the same corner wasn't right, so water pooled right next to the window well. After a lot of rain one day their basement flooded. They never regraded it, or did anything else but repair the damage. I doubt they disclosed this, but I moved before I could ask the new owners, and since it's resold a couple of times since I doubt the current owners have a clue either. So the current owner of a property may not know the actual history of a house.

Aug. 20, 2011, 02:07 PM
If you are really interested in a particular property, you could hire an site engineer to help you decide if there are any problems. You could even write a contract on a piece with a condition that it pass the engineer's inspection.

Aug. 20, 2011, 03:17 PM
The title report will note the existence of a floodplain, and the flood map will show you things like the base flood elevation and other important details.

A Topographic map will show you the features of the land, elevations, contour lines, and other features.

Your soil maps will show you what kind of soils you have.

Most, if not all, this information can be obtained free or at low cost through your county GIS. Many county govts have it on the county website. You can just type in the deed book and page or parcel number.

You can overlay your property lines onto the soil and flood maps, creating one big map. Or you can order separate maps.

If you are trying to plan out your farm, you can take your survey or other maps and transfer it onto graph paper. Make everything to scale. You can position buildings,fence lines, or any other structure on the graph paper. Experiment, change layouts, consider traffic patterns, location of manure pits, shavings bins, arena, etc.

Don't walk away from property that has low lying areas. You can often plan around them, or make a pond, or save that area for late summer grazing.

Your extension agent and soil and water conservation office can provide free and invaluable information as well. They will meet with you, visit the farm, provide referrals, all kinds of things.

Good luck.

Aug. 20, 2011, 05:13 PM
Never underestimate asking the neighbors. I know it can be really hard to observe a property during heavy rain or snowmelt but the neighbors may have seen it, been impacted by it or heard about it.

After that you have the list. Flood plain maps, topo maps, soil types and vegetation.

Around the house itself even simple things can make the yard drain much better - DH put in an underground system to carry the water away from the gutters. I had used to gauge how floody it was going to be by the size of the puddle in the car parking area - with that gone I had to find new ways.

Things like an arena can be constructed with engineered drainage systems. Tractor work to create crowns and swales and dedicated wetland areas can make something that works for us much better. The only problem with that is that some municipalities require a lot of permitting if anything you do changes the drainage, which can make it cost prohibitive.

We have one sink and two karst type springs on our place, and if it rains hard enough we get a number of bubblers as well. You can guesstimate the rate of rainfall by watching the front drainage. All the water vanishes into the sink, which you really can't see and would never guess is there. As it rains harder we begin to exceed the culvert capacity under the driveway and it goes over the driveway and then it finally exceeds the sink and runs down the neighbor's frontage. His culvert is set high enough to where he will get a pond and we have not yet seen one form - so he has fractured rock under his lawn as well. The day he gets a pond we are going to be swimming.

If you look hard at the driveway you can see the collection of fine sediment/gravel where there has been standing water, as well as the larger rocks left on the upper parts of the driveway/little bitty gullies. We could hide this by adding new stone or paving of course.

Aug. 20, 2011, 05:47 PM
Be aware that an older land title may show the "old" flood plain. FEMA has recently updated the flood plains and the title may not show the new lines.

This was done post Katrina, I believe within the last 2-3 years.

Aug. 21, 2011, 12:23 PM
Swamp grass, and we have actual cat-tails in the drainage ditch. We knew before we bought (and saw the house in the spring w snow on the ground & rain in the sky) that there was going to be water, but that everything important was going to be high and dry.

We have a property that is low-laying (as is most in this area) but our paddocks have a drainage ditch and we can easily handles a few feet of rain/water if it ever came to that.

The house is up on a slope from the barn, the entire barn has drainage and traction in the concrete around door-ways, there is also a pond opposite the paddocks for extra water on the rest of the property. Bring on the rain!

Pics of the ditch:

It is a really good idea to go and look at houses on rainy miserable days in the early spring. Another one we were looking at buying, had a HUGE crack in the foundation letting in all kinds of water - we'd never have been that if it hadn't been pouring.

Aug. 21, 2011, 02:57 PM
Here's the link to the Flood Map site:


Aug. 21, 2011, 06:41 PM
Hay fields should already have drains. Ask the owner. Then, a site engineer.

Low spots are supposed to be drained, from my understanding, for good land management on a farm, but I don't know how often you don't find that. It would be a negotiating issue for me, depending on the type of farm I was purchasing.

For example, in the big hay field at the back of my new BO's property, which is basically on a hill, is a swale, at the bottom of which is a drain the type you see at the side of the road. At the bottom of the field is a pond fed by a stream, but the area is dry, because it was properly drained.

Just a thought.