dlf,

you have said very little with which to analyze your hydraulic system. Your system could be analyzed in 3 parts. Storage, distribution and control. Information to provide:

1. Dimensions of collection pond or capacity in gallons
2. Height in feet from pond surface elevation to garden beds.
3. Will you be terracing the beds on the slopes?
4. Will the different beds be for certain types of veggies?
5. Will each bed be alotted a certain amount of water per week.
6. What are dimensions of the beds? How many?
7. What are the flow rates of the emitters? Emitter's flow rate are usually rated from the operating pressure they will experience. With little pressure they may not work at all or very unevenly especially with water that is not from a clean source even with filtering.
8.How many drum are you planning on using and will they be linked together?
9. How much does it rain per year in your area. What rainfall can you expect per month for your growing season.

10. How big an area does your pond collect runoff from rain.
11. Does it have to be an automatic system?
12. How many people are planned to use the Community Garden.

I can help you with your plan with more info. Thanks

Check out the Community Garden forum especially past threads on irrigation systems. Good luck. Aloha

1) The pond is about 12 feet wide and the st on the surface and 25 feet long at the longest the surface. It is 5 feet deep at the deepest point but the width is considerabaly smaller at the bootom than at the top

2) The pond surface is at about the same level as some of the lower beds but it will not be used directly for the irrigation system.

3) The beds are already built and are terraced.

4) short answer no. However at any given time we will try to group plants with simmilar watering needs

5) No, However there is only so much water avaliable for the wole garden. We can't use up all the pon water or our fish will be very sad and our modest sized rainroof collection system might have a hard time filling the barrels.

6) I messured the beds today and they are about 8 ft X 5 ft for the most part. There are 8 beds that size and 1 bes that is 3 X 8.

7) the emmiters are non pressure compensating 1/2 GPH at 30 PSI

8) The drums will be linked and were planning on getting between 4- 6 (depends on how cheap we can find them for and how much water we can capture)

9) Average annual precipitation is 45 - 50 inchesdistributed as follows

Jan 3.3 Feb 3 Mar 3.9 (APR 4 May 4.5 June 3.7 July 4 Aug 4 Sep 3.9 OCT 3.5) Nov 3.8 Dec 3.5 () growing season

10. Currently the pond collects runoff from a 10 X 25 tarp plus its surface area. However, the roof with gutters for collecting rain will be over top of part of the tarp (approx 56 sq feet)

11. Yes. Our club meets every week once a week nobody is at the garden to turn water n and off at other times. I found a 0 PSI timer and automatic
    rainshutoff.

12. I think you misunderstood. It is not a community garden. Rather it is a college Club. (Organic Gardening Club) We hope that with the irrigation system we will be able to donate a box of produce a week to a local shelter plus have some extra for the members of the club. We want to do this from the 8 8 X 6 beds. We do have a few extra beds that I didn't include becuase we don't plan to irrigate them. Right now with hand watering once a week we get good production in the fall and froma few specific crops in the summer but many crops fail do to lack of moisture.

Thanks for any help you can give.

dlf,

Pond capacity is 10,000 gal. With fish let's say you're able to use about 5,000 gal. Will the pond be used to pump water to the barrels? A one-inch rainfall will produce 60 gallons of water from the tarp, 35 gallons from the roof and 180 gallons in the pond directly. 6 barrels x 55 gallons is 330 gallons capacity. Use oil for mosquito control if the water stays in the barrels longer than a week.

Jan. you will collect 900 gallons; Feb. 825, Mar. 1,050; Apr. 1,100; May 12,300 and so on.

Is the club active over the summer months?

Now let's look at the irrigation needs. An 8' x 6' plot needs about 45 gallons a week. Your eight plots requires 360 gallons per week or 1,440 gallons per month. If the weather is unusually sunny and warm more water, if overcast and cool less water. Drip irrigation, although automatic and efficient may not provide water deep enough in your case( depends on soil type). Also, drip with emitters are more likely to clog and attached by ants. Mulch is extremely important in your case to minimize water evaporation from the soil. Research how roots grow and thrive. That is the a key factor to successful gardening. I would recommend a submersible pump in a barrel and in the pond with a hose system to hand water and soak plants deeply. See if you can get a small submersible pump that can run off a car battery, then at least use it to fill the tanks from the pond if necessary. How about transporting the drum in a truck bed, fill elsewhere and empty at the garden when needed. Good cause, tough job. Good Luck.

dlf,

You might look at "earthtainers". Plants are watered from the bottom up from water reservoirs below the soil. You only add water that the plants transpire. Good match for your project. You could even set up auto fill for these containers. I am growing tomatoes in one and it really is good at water conservation. Aloha