Pumped storage - was two alternators - Page 3

 On Mon, 22 Jan 2007 18:57:47 -0500, "daestrom"


Must be that new math.  1 gallon per minute, times 60 minutes, times
24 hours, times 30 days = 43,200 gallons.  3.33 gallons per minute
would be 142,560 gallons.  I'm only trying to get 50,000 or 60,000
gallons a month.   One of us is missing something.  How did you get
7200 gallons???

   somebody@somewhere.com wrote:


You don't say what country your in, or what the local Govt. might have
in the way of Regulations for Private Dams.  Second, if you build a
road on the top of the dam, you better figure on the 100 Year Flooding
Profile for the stream, and have an overfow designed into the Dam, that
can handle a 100 Year Flood Overflow Event.  If you didn't do this, and
you got a "Big Dump" and your Dam failed, you would be liable for all
downstream damage.  Likely, all this would REQUIRE a complete Site
Survey by a Profesional Civil Engineer credentialed by your local Govt.
OR, you could do it "on the cheap", and just build it and have the
"Personal Liability" sitting squarely on YOU, if you figured wrong,
and something happened.  Dams are not as easy to deal with as Catchments
when designing MicroHydro Power Generating Systems.

Bruce in alaska
--
add a <2> before @

 wrote:


Hi Bruce,

Good points and all part of the reason I'm going with such a small
dam.  Five feet total height is not much higer than some catchment
wiers, and appears to be well within the sane limits of construction.
The amount of impounded water will be minimal, the stress on the
structure will be minimal, and the chance of catastrophic failure
small even if the road washes off.  Given the lay of the land, even if
the dam was instantly removed by a giant hand, the rush of water would
spread out and down to a maximum 12" tall flow even before it exited
my property, less in flood stage when the stream is wider.

Downstream has a total damage potential of two overbuilt rural highway
bridges, and one abandoned home near the stream.  At two miles
downstream the branch enters a major tributary with at least 50 times
the flow, where any increased flood flow would be totally lost even in
the normal flow.

Another point to consider is that the impoundment area will start to
silt up whenever there is excess flow, and within a year or two the
quantity of impounded water will be very small indeed unless I muck it
out.

In short, I am more concerned about the quantity of water that the
pumped storage pond will be impounding and could lose in a failure,
rather than the small restriction on the stream.

Looking at aerial photos and geodesic maps, I see three other similar
dammed areas on tributaries within 3 miles, and there are about a
dozen other farm and personal fish ponds in the same area.  I guess I
didn't mention that the state and county laws allow rural landowners
to do just about anything they want on their land, and there is
literally no building inspector.  FWIW, the existing house on the
property would no more pass an inspection than a cardboard box full of
matches around an electric heater.  This isn't one of the
over-regulated over-taxed nanny states.