16-09-2003, 11:22 AM
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using sump water for lawn irrigation
(Andy) wrote in message . com...
Okay, I see your point about inadequate water supply. But ignoring
that, how could I use the sump water for watering the grass? Right now
it's all going to waste. Any little bit to conserve water helps,
right? If I'm going through the trouble of digging a foot deep trench
(frost line in my area is 42") just to dump it into the storm drain,
I'd rather do the work to reuse that water (ie, water the grass). I
don't think I appreciate grass enough to spend $50/month watering it,
so supplementing with sump water would be great.
Andy
"donald girod" wrote in message ...
In dry weather, when the grass needs water, the sump pump will not deliver a
significant amount of irrigation. Two times a day translates to maybe 20
gallons of water, equivlent to watering with a sprinkler for 5 minutes or
less. So this would be a lot of trouble to go to to achieve a negligible
benefit. You need about 1500 gallons to water the front yard thoroughly
(assuming 50x50). A large storage tank for the sumpwater would work, but
this seems impractical.
What most people do with sumpwater is drain it toward the street where it
can flow into a storm drain. This requires a trench about a foot deep (or
more) and some pvc, and then a "bubbler" at the end so that the water can
come up to the surface. Generally you put the end in a gravel-filled hole
(dry well) so that the pvc can drain completely and not freeze up.
There are a whole lot of reasons why doing this is impractical:
As has already been pointed out, to water an average lawn takes
thousands of gallons of water at one shot. A lawn needs to be watered
deeply every 4 to 7 days, when it needs it. A sump pump ejects a few
gallons at a time continually. There is no practical way to
distribute this to the lawn without storing it first, which is going
to require a large tank to store it, then a pump/sprinkler system to
distribute it. If you somehow tried instead to do this continually to
even small sections of lawn, you'll have the lawn wet for very long
periods of time, which is very bad for the grass.
Even worse, as was pointed out, you get the most water when you don't
need it, ie when it's been raining a lot. When it's dry, you get
little or no benefit, making it pointless. The only solution to this
problem is to have a very large cistern so that water accumulated is
enough for at least several waterings. In some extreme environments,
people do have large cisterns for this purpose. Those are generally
filled with rainwater through the home gutter system.
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