Minimal Elevation re: riverside

[FrankInWI]

I have a property near a river.....not too much rise in the land.  I'm 300 ft from river and can't imagine the river getting to me.  My neighbor ( a little closer to the river) built already and put in many many truck loads of sand before putting the house on top....maybe 6 feet of sand fill?  Anyway, he's in building and good naturdly mentioned he'd bring his equipment up someday (weekend gettaway for them, retirement home for me) and "shoot me a line (laser?)" determining the minimal height to start building from on my lot.  
I always just assumed I'd be ok building on the ground as is.  Apparantly for insurance (and code?) purposes I have to be careful to be at above some minimal height above what the water could do at some point in time?  (i.e. 100 year flood?).   Would really appreciate some of your wisdom on this one!  Thanks much / Frank

[MIEDRN]

The state of Michigan has a website that contains a map with flood/water levels. I'm sure other states would also.

Did you try "100 year flood plain for......." in a google search? You might come up with it.

[Amanda_931]

If it's been normal for people to get flooded out--or in--along that river, and you think it's something you can handle, then do what others have done.  

No drywall, for instance.  (Aparently Lowe's is going to handle plans/materials packages for a handful of Katrina houses)

But, my county had a flash flood--unheard of in these parts--a year or so ago.  Some little storm sat over the valley of the Green River south of town and rained really hard for a couple of hours.  I think I got about 1/2 an inch up north of town over the course of the whole day.  It did a lot of damage.  Floated (away!) a lot of tanks at the newer propane supplier's lot, for instance.

I remember being fascinated by a Mary Roberts Reinhart mystery when I was in my teens set in Philadelphia? Pittsburgh? in a neighborhood that was used to being flooded.  People moved out for the duration, came back and cleaned up.  Every year.  Don't remember which book it was.

The floods in the Reinhart story, IIRC were the kind where you had a few days warning.  There are a handful of places on the Tennessee river in Hardin County like that, a few houses up on stilts, and a handful of RV developments, where I assume that somebody has the keys or the authority to move your trailer to higher ground if you don't hear about it in time.

A four foot wall of water heading to your house is something else.

[glenn-k]

I had a customer who wanted to put a shop near a slough that flooded once in a while - he was a little put out that I insisted that we put in about 4 feet of fill.  

He wasn't put out a few years later when his shop and pad was the only thing sticking up out of the water  This has happened several times since then.

[ailsaek]

Floods happen.  The river in late summer is not the same river as the river in spring.  If there's not much of a rise, rivers can definitely go more than 300'.  We had serious rain and major flooding this spring in northern Mass and southern New Hampshire and Maine, and the rivers went a good deal further than 300' from their usual banks.

Check out the pictures at this link http://kutv.com/topstories/topstories_story_134123452.html - that could be you.

[n74tg]

I have lived places that had 100 year storms three or four times in 10 years.  I watched those people get flooded out, rebuild, then get flooded out again.  After a couple of cycles of this, if they are not bankrupt already, they get smart and move up to higher ground.

Our world's "bad" weather seems to me to be getting worse, much worse.  Living anywhere near a 100 year flood plain would make me very nervous.  If you absolutely have to live there, then please add a several feet or more of elevation to your house (above the 100 year flood elevation).  Use stilts, bring in rock, but do something.  If you bring in sand, stabilize it.  

Please get rid of the thinking "I just can't imagine that happening"...IMAGINE it, it CAN happen and it is ugly.

Don't take your advice from the new guy who just built his house; take the time and go find the old folks who have lived there for generations.  Ask them what this river can do and has done.  Go to the library and look for old newspaper articles, back even before the old folks were born.  

I don't mean to come across harshly or negatively, I've just seen way too many people wiped out by floods living in areas they had no business living in in the first place.  I know this isn't your personal situation, but just because a developer decides to build a subdivision there doesn't mean it's a good place for you to buy a house even if other people have already started buying those houses; even if those houses look real pretty and seem to be cheaper than houses in other subdivisions.  WHY are they cheaper?  There IS a reason.   I am reminded here of a picture of a new subdivision built right next to the levees of the Mississippi River.  The top of the levee is above their roof and the Corps of Engineers is now saying the levees are is bad shape.  

Be safe.

[FrankInWI]

Thanks for all the feedback.  I won't minimize the importance of this.  I always thought the after affects of a home flooded out were one of the worst things to deal with.   A fire leaves you with a clean slate, a flood can leave you in the middle of a diferent kind of heartbreaking mess.
The neighbor builder was the two sons, who are pro's, of the widow owner.  He offered to shoot the line to my place to know how much to bring it up.  I'm sure going to take him up on that!  In Wisconsin we do basements, but not with the high water table here next to the river.  It's where I want to be though for recreation now, and for retirement in a few years.  
I'll make sure to make it high to keep it dry.  It's going to be an odd looking place.  Small lot has me building two story not to use up the lot and now I have to start high!  Going to look might odd maybe.  If anyone happens to see attractive distroportionatly tall cabin / house....point it out.

On a slightly diferent topic...someone mentioned goodling "one hundred year flood".  Of course that led to good info. I am normally one to go to google for most any info these days.....it's absolutely incredible how that put some much information at our fingertips.  I have a couple teen age boys and we talked about how for any earlier generation to have to go to the library, and / or go to the already out dated encyclopedia in our home.  (the one we got an issue of each time we bought XX ammount of groceries!).