Skip to Content.
Sympa Menu

market-farming - Re: Help with irrigation - domestic well use

market-farming AT lists.ibiblio.org

Subject: Market Farming

List archive

Chronological Thread  
  • From: Marcie Rosenzweig <fullcircle AT jps.net>
  • To: "market farming" <market-farming AT franklin.oit.unc.edu>
  • Subject: Re: Help with irrigation - domestic well use
  • Date: Sun, 30 Jan 2000 17:20:51 -0800


Here I go again, this time on irrigation. I just realized I could teach a
1 hr class on this and still have stuff left, so I'll break it up.

Fastest way to measure your well output. You need

A short length of hose connected as closely as possible to the well-head.
A watch with a second hand.
An accurate measure of at least 1 gallon with marks at 1/2 And 1/4. You
can prepare this by recycling a one gallon jug in your kitchen and
measuring accurately with a measuring cup.
A five gallon bucket and a funnel.
This is easier with two people, but not necessary.

Turn the hose on full bore. Start at a convenient second hand point.
Stuff the hose in the 5 gallon bucket, let run for 15 seconds and remove
the hose immediately.

Carefully measure the amount of water captured in the 5 gallon bucket.
Mutliply this amount by 4 and you have gallons per minute. Multiply that
amount by 60 and you have gallons per hour.

Things to remember when planning an irrigation system:

If you're running off a domestic well -
Domestic wells have pressure tanks and regulators on them to provide water
to the household appliances at something that approximates urban/suburban
water systems pressure, generally, around 60psi. Our regulator turns on
the pump to fill the pressure tank until water can be delivered at 60psi,
then shuts off. When we draw water, and the ability of the pressure tank
falls to 40 psi, the regulatory turns the pump on to refill and
repressureize the tank.

You want to draw enough water when you irrigate to keep the pump running
continuously rather than kicking on and off frequently. The on and off
cycle is really wearing on the pressure regulator and the electronics.

You also need to be mindful of the recharge capacity of your well. This is
the rate water from the surrounding strata rushes into the area where your
pumphead is. Pull too much water out too quickly, and you may run low,
have to shut down and wait for the well to recharge.

Also, to keep from contaminating your well with backflow, put an
anti-syphon valve on your irrigation main as it leaves the well. We start
with 1 inch PVC going to the plots and have an anti-syphon valve on it.
Additionally, I use 3/4 inch electric anti-syphon valves at the standpipes
at each plot head. I run 3/4 inch black headers off those valves.

We irrigate off our domestic well. It puts out 10 gallons per minute
running full open 24 hours per day with no recharge problems. I plan my
irrigation to use 8gpm, or 80% of my well capacity, so I have a cushion. I
also plan it so I can irrigate everything in 6 days so I have a cushion
there. We use Toro irrigation clocks to run the watering program.

Good references on country plumbing and irrigation are:

Irrigation Scheduling: A Guide for Efficient on Farm Water Management 21454
$7.00
Micro-irrigation of Trees and Vines 3378 $25.00
Drip Irrigation for Row crops 3376 $25.00

All available from Univ. of CA Ag and Natural Resources 1-800-994-8849 or
make a check payable to UC Regents and send it to UCANR Communications
Services, 6701 San Pablo AVe., Oakland, CA. 94608-1239. If you live in CA,
you may be able to buy these at your local extension office. You'll get
them faster that way.


Somebody help out here, I've loaned my copy of a book called Country
Plumbing. It talks all about wells, water and septic systems, but that's
as much as I can give until I get my book back.









Marcie A. Rosenzweig
Full Circle Organic Farm
Auburn, CA






Archive powered by MHonArc 2.6.24.

Top of Page