Zbox wrote:

I'm moving into a house in the rural area and I picked up three 50
gallon plastic (clean) barrels that I would like to use to collect
rain water and then use the water to provide water to flower beds and
brushes around the house. The problem that I'm seeing is that the
barrels are around the back of the house, and the plants to be watered
are around front. Does anyone know of a pump that I can use that can
problem the pressure needed to pull water from the barrels and apply
the neccesary pressure 15 to 20 psi (I think) for a drip irrigation...


I've not been a fan of rain barrels since they're only full when it
rains and then you don't need to water. Rain water stored for any length
of time in containers can grow algae which will clog drip systems (if
light is excluded from the interior of the barrel, this can be avoided
to some extent, but the barrel has to be really opaque). Also, 150
gallons of water doesn't go very far on a garden. If you want 1" of rain
equivalent per week, that's 30,000 gallons/acre, or about 0.7 gallons
per square foot. Your 150 gallons will water around 200 square feet of
garden at that rate. 100 square feet if you have to water twice, etc. Of
course, that's assuming you're applying 1"/week of rain equivalent.

Having pointed out the negatives, I should also point out that you can
use maybe 10% of that just to keep plants alive, so it can be used on a
larger area if necessary, just not as effectively. You will find other
people who love their rain barrels. If the barrels take water from an
extended area (such as a large roof), you can multiply the amount of
rain water you get onto the garden by the ratio of the area of the roof
to the area of the garden.

The most effective way to use the rain water from the roof is to direct
the downspouts directly to the garden. The only drawbacks to this
approach are (1) the extra downspout plumbing (possible elevation and/or
routing problems) and (2) the possibility of erosion from a large flow
of water from the downspout. Don't try to restrict the flow of water in
the downspout: it needs enough flow to be able to clean out leaves and
debris.

I do use a barrel for water. I have a greenhouse with a buried hose from
the house to supply water. In the spring, the buried hose is frozen, so
I have to use a barrel in the greenhouse to supply water when I first
turn the greenhouse on. I bought a portable submersable sump pump at
Home Depot (about $50 10 years ago). It has a hose outlet. It provides
around 30psi for watering plants. In the greenhouse the 50 gallon barrel
lasts about 3 days tops before I have to fill it again. At that time I
have around 100 square feet of flats to water. (Some water is wasted in
the process, mostly by runoff). I don't use a rain barrel system for the
home garden, which is about 1/4 acre. My home water system (a well) can
supply it when necessary. The garden soil drains well, but not so well
that it can't retain some rain water for a week or two. We generally get
enough rain (in MA), so I only have to water it about once every other
year. I use a drip system since that's the most efficient type and I
have the equipment at hand.

Check into the pressure needed for the drip line. Some drip line will
operate on as little as 8 psi.

Rule of thumb: 1 foot of elevation equals 1/2 psi of water.

When you consider the cost of the pump, it may be cheaper to water the
garden from the house water supply, assuming you have a well. When you
consider the maintenance on the system, it's certainly a lot easier to
use the house water supply. Have you considered using grey water for the
garden? (Do not use it with a drip system -- it will clog quickly).