[Greenbuilding] [BULK] Flood Resilient Housing

[Lawrence Lile]

1.  People around here say, if you build on the river, plan to build
again.  

2. Stilts are the way to go.  We have a whole town up on stilts now,
Lupus, Mo Population 29, with five or six houses up in the air.  These
were all flooded up past the first floor ceiling in 1843, 1956, '73,
'82, '86, '93 and 94. Note the increasing frequency over the last 150
years. People finally got sick of it, and started jacking up the houses.
12', 14' some 18 feet in the air, old houses originally built over a
century ago.  Forget earth contact, unless you want to truck in a
mountain of soil. We are talking AIR contact architecture. 

3. The 100 year flood line was passed two years in a row here, in '93
and '94.  The 100 year flood line, for practical purposes, DARN NEAR
GUARANTEES that a flood will probably reach at least that high during
your lifetime.* You need to be well above the 100 year flood line. Your
town, if it is building a levee to the 100 year flood line, is fooling
itself.  Translate this language this way: that's the flood that has a
1% chance of happening every year, and it CAN happen every year. Try to
be several feet above the 500 year flood line. Think about tying up your
boat to your house, when the 500 year flood comes.  

4. Global warming doesn't sound so scary, until you understand that it
is really Global Weirding (Amory Lovins coined this term).  Historic
weather extremes, especially floods, are likely to be exceeded.  I won't
be surprised if there are 4 or 5 "100 year floods" in the next 100
years.

5. Flood plains also make terrible foundations, generally, with squishy
soils.  Plan to go pretty deep with piers or pilings.  

6. Regulations around here prohibit people from boxing in the first
floor of the stilt houses.  Generally you park your car under the house,
park your lawnmower, or use it as a covered porch.  Some people put a
screen around it, using that open slat board stuff, or chain link fence,
but if you put up much of a wall, you are putting up a sail that could
push down your house in a flood.  

7.  Lots of insulation will make the house plenty efficient, although
you'll have to insulate the floor just like a ceiling.  Solar still
works, although mass will become more expensive to place, up in the air,
since you have to support it with something.  

8. I spent all night stacking sandbags to the 100 year flood line one
night with all the neighbors, then next day, sailed over the top of our
puny wall in a canoe.  The water didn't get the memo saying how high it
was supposed to go before it stopped. The water in your river won't get
that memo either.  

9. OLD style materials come through floods better than new materials, if
you have any construction below the 500 year flood line.  In Lupus, the
houses made with plaster on wood lath, wood floors, solid wood cabinets,
and solid wood siding would be nasty after a flood, but people would
hose them out, paint, and move back in.  The houses made with sheetrock,
particle board, plywood, carpet, and paneling would have to be gutted.
Brick and masonry, unless the water knocks it down, come through OK.  

10. Imagine the coolest treehouse you always wanted to build as a kid,
and build it.  Think decks overlooking space, tall staircases, and a
winch to haul up your furniture, a lookout crow's nest on the roof.   

*Hopefully Nick and Reuben will forgive the loose statistical math here.
A 1% chance of something happen does not, mathematically, guarantee that
it will happen once in 100 years, or ever.
 
Lawrence Lile, P.E., LEED AP
-----Original Message-----
From: greenbuilding-bounces at listserv.repp.org
[mailto:greenbuilding-bounces at listserv.repp.org] On Behalf Of Ross
MacLeod
Sent: Thursday, April 05, 2007 2:59 PM
To: greenbuilding at listserv.repp.org
Subject: [BULK] [Greenbuilding] Flood Resilient Housing
Importance: Low

I currently live in a flood plain that has not experienced a major flood
in
nearly 30 years.   The community has recently approved the construction
of a
berm to 'flood proof' the area against the possibility of the one
hundred
year flood event.   I recognize that with climate change these intervals
are
optimistic, and we can reasonably expect in my life time a more extreme
event that would flood my home (the basement, and likely put the first
floor
under a few feet of water).

Despite the risks, however, I would prefer to stay in the area if I can
find
a reasonable way to adapt (within reasonable cost parameters).   At this
point I am just beginning to explore what would be involved in building
an
energy efficient and flood resilient house.  I have not found much out
there
at this point.  Several homes in the area have been built recently with
so-called flood proof basements, but these are expensive and from what I
can
see provide a poor solution to serious flood challenges.   I have read
of
some extreme 'floating' homes being built in Holland, but nothing very
innovative beyond that.   I thought that a hybrid structure based on
stilts
interleaved with collapsible sections of wall or ''curtain" (up to the
first
floor, which would be raised several feet), might be interesting.  Does
anyone have any good pointers to information, or innovative thoughts in
this
area?
_______________________________________________
Greenbuilding email list
List info:
http://listserv.repp.org/mailman/listinfo/greenbuilding_listserv.repp.or
g
List email: Greenbuilding at listserv.repp.org
Managed by BuildingGreen, Inc. http://www.buildinggreen.com
      publisher of Environmental Building News and GreenSpec(r)
Hosted and archived by REPP / CREST http://www.crest.org