h a l f b a k e r y
add, search, annotate, link, view, overview, recent, by name, random
news, help, about, links, report a problem
or get an account
Tidal Waves to Oxygenate, cool and clear streams/small rivers
Because of a lack of flow in many
due to water diversion or habitat change,
three problems have risen: The lack of
rapids lessens airration, the slower water
speed raises water temperatures and also
allows faster sediment buildup in
breeding grounds for certain fish.
streams in hawaii, because of the
above reasons do not flow regularly into
the ocean like they normally would. A
slower water flow means that sand banks
always block the entrance of the river/
stream mouth to the ocean and the only
time that they open is when a big rain
comes. When this happens, sediment
would have normally been flushed out
slowly comes out all at once, blanketing
and killing nearby reefs.
Many native amphidromous fish species
not adapted to restricted water flows,
higher temperatures and low oxygen
levels, causing them to not complete
life cycle of returning from the ocean to
streams and rivers.
In some local streams, large-diameter
pipes have been installed to accomodate
for the constant sand banks, but they
themselves, if not cleared frequently, can
be themselves clogged as fast as
My idea: Large-diameter pipes by
themselves leave maintenance problems,
but install a pressure or tidal activated
valve and it will clean itself. Even with a
tidal difference of only two feet, enough
pressure can provide a rush of water flow
that would serve different purposes:
The sudden rush of water in and out
would: airrate the incoming water, clear
the pipe of sand and debris, provide a
more constant unsettling of sediment,
allow for amphidromous fish life cycles.
It's a large pipe with a valve activated by
tides or pressure that connects locked
streams to the ocean. It is self-cleaning
and improves stream conditions for
When enough pressure difference is
detected or tides are determined, the
valve opens and a small tidal wave is
created. it's like a laxative for a
||Totally not seeing how tides (a seawater phenomenon) will help freshwater streams. You've either got to install pumps, which would risk harming the fish populations, as well as get clogged in turn, or use seawater, which would kill many of the fish outright, as well as be impractical above sea level.
||Some dams in the mainland US are using artificial flooding to mimic the seasonal floods which carry silt downstream, and refresh local water habitats. I wonder if that is what you are groping towards?
||Streams were originally affected by tidal
swells before roads and bridges and
water diversions were installed. It is
just a restoration of a natural
occurance. The native amphidromous
tolerant of both full salt and fresh
water. They are actually dependant on
water flow cycles: if they don't detect
water flow cycles that can take the eggs
out to sea, they won't mate.
||It was also my observation of the recent
Japan earthquake which caused 3 foot
tidal swells, sucking water in and out of
||You don't have to intall pumps, you are
just waiting for sea level height
differences to open the valve. For
instance: The valve is closed after being
opened during low tide and water
rushes from the stream out to the
ocean. The level of the stream and
ocean are now low. The valve closes
again, and time is allowed to pass.
High tide comes and the ocean water
level is now two feet above the stream
water level. When this difference is
detected, the valve automatically opens
to release a torrent of water into the
stream. (these streams are salt, brakish
and fresh water, depending on the
water height. salt water rises, brakish in
the middle and fresh water sinks to the
||yeah, it does seem like my anno is more
clear. call it a second draft.
||that idea does make sense too I must say.
Constant flow (although restricted much at
times) would encourage aeration as long
as the flow was allowed to splash, which,
mechanically, would pose little challenge.
||Why do the unmaintained pipes get
blocked? Presumably either from
stream gravel, or more likely ocean
sand carried in on high tide. How does
the valve avoid the blockage?
||//it's like a laxative for a constipated stream.//
||Sand blocks pipes coming in with wave
action and high tides. It should be
mechanically simple to allow a valve to
open with some sand blockage, allowing
water to slowly take the sand out to sea or
into the stream.
||I've never really known what an enema is..
I never cared to look it up. And i'm not
going to look it up after this anno
although I AM tempted. Lazy.