recent research on beaver dams
has shown that the upstream slope
beneath the water
is a lot shallower than the downstream
slope
meaning that they can hold back
considerably more water
something that i can demonstrate using
this pair of door stops now if the
beavers got it wrong
and built their dam with a sheer face
upstream
let’s imagine that the door represents
the weight of the water in the lake
if the mass of water is greater than the
mass of the dam
then it’s easily shifted by that water
however the beavers don’t do that do
they they have the shallow slope on
their dams
and this means that when the weight of
the water meets the dam
the vertical forces pressing down
outweigh the horizontal forces
of the water pressing downstream and the
dam
is immovable in the real world of the
beaver
as the horizontal forces of the water
meet the dam they become
vertical and pin that dam to the base
of the lake and that’s how it can hold
back
a lot more water
whilst we haven’t copied beaver dam
building human engineers
have plumped for some of the same
solutions
just like the beavers we also bow our
dams upstream
a proven way of engineering these
structures to be strong
and incredibly long lasting
so long lasting in fact that beaver dams
marked up on maps of north america
from 1868 can still be found in use
today
using sticks stones rocks and mud these
structures
are clearly built to last so just how do
these master builders do it
and what can we learn from beaver
engineering expertise
beavers really are the ones which in our
field of hydraulic engineering
provide by far the the most interesting
and the most
far-reaching solution to problems
dr gerald muller is an engineer
convinced that when it comes to the dams
of the future
taking a log out of the beaver
construction manual
is a very sensible approach beta dams
are
very interesting from the point of view
that a they are very strong
and b you use natural material which is
available everywhere
which is quite cheap it also is a
nature-based solution
where we can reuse the material easily
if you would build a dam from reinforced
concrete
and you want to take it away you need to
get the jack hammer out and hammer
it apart and you are left with some
steel and
a pile of rubble which cannot really be
reused
and from that point of view a solution
like this is really very
near ideal i must say
[Music]
