I'm currently spot watering a 2-acre market garden (mixed vegetables) from a dug well. So far (two years), I've gotten by mainly with rainfall, but this year I want to have a reliable source. The goal is to have a reasonable volume of water available for dry spells, but not necessarily to water all the time. The field is more or less flat, and dips down in one corner, where we intend to dig a pond, 20' x 50' or so, by as deep as possible (maybe 8'-9'). This would be done by a high hoe contractor. There is no electricity available there. For getting the water to the field, which means up the slope and then about 500' to where the garden starts, the plan is to get a gas generator and a shallow well pump and a reservoir tank (I'm also looking into sprinkler pumps, which may eliminate the reservoir?) For distribution to the field, the idea right now is to duplicate the existing well set-up, which is 1" PVC flexible pipe, attached to a faucet off the barn well. It goes about 300' to the garden, and then down the length, which is about 450' (x 200'). I'm not sure what the current PSI is, but we can get about 4-5 GPM right now, and the pressure is fine for hose work, and running 200-300' of soaker hose or drip tape (that's the extent of what's been tried). So I'm hoping that the pond solution could work as a simple switchover from the well connection. For delivery to the beds, the current plan is a combination of drip tape and various spot methods (lawn-type sprinklers, soaker hoses - I realize sprinklers need quite a bit of pressure). Depending on the crop, some beds would be set up with permanent drip tape (in place for the year) and could be turned on as a zone (sections are 50x50, with 500' of tape to cover all beds per section). For other crops, it'd be manual, either dragging in fast soaker hose, or sprinker, or by hand. I don't want it to be too makeshift, but on the other hand, I can't see (budget, time) laying in a full drip system. I want to get the pond in place, and be able to deliver the water as a first step. I imagine this is a fairly common general situation (drip from a pond). Do you have any suggestions, warnings, comments? Thanks!

Todd, Man you are doing the hard stuff. Two ibuprofen is better. Here is the hydraulics. Approximately 0.5 psi for every foot of elevation the water level is from the garden surface. For example if the height difference is 10 feet you will experience 5 psi at the garden outlet pipe. The pressure will decrease as the height of the water level decreases. In low pressure water distribution pipe sizes need to be bigger because your flow velocity will be low. See what flow your system will deliver by filling a 5 gallon bucket up and timing the fill. Do it several times and average the gallons per minute. You will now know how long it will take to deliver a certain amount of water to a zone. At least you won't need pressure regulators but probably a filter screen if your going with drip or soaker hoses. Think about pvc with holes drilled into it at what ever spacing you need(I can help you with this). You need to calculate the usage flow rate of the drip tubing or soaker hose to plan correctly for even distribution. Who will coordinate the water regime for the garden? Talk to a local landscaper to help you and you will advertise his name in the garden. Trial and error is a way of learning life. Aloha

BB, Let's see 20 plants at 1 gal per week equals 20 gallons per week. Assuming watering cycle twice a week that is 10 gallons per cycle. Storage capacity of 1,200 gal allows 120 cycles times 0.8 equals 96 cycles or say 100 cycles. Two cycles per week gives you 50 weeks. Your storage is more than adequate. So much so you will have to treat for mosquitoes. 1/2 HP centrifugal pump has a flow rate of about 35 gpm with low pressure. See link below: http://images.harborfreight.com/manuals/94000-94999/94651.pdf Each cycle will take less than a minute but should be monitored and time should adjusted for actual health of the plants. Your check valve is good enough in my opinion. With drip you need good filtration or it will clog emitters. Thank about using 1/2" pvc pipe with 1/16" hole drilled in it for watering. You will not need to filter as good and less clogging. You can go back and re-drill hole if you need larger hole to reduce the pumping time. There are past threads in GW on this subject. JMHO Aloha

From page 21 in this Rainbird design manual the maximum length of one lateral with 20 psi source is 294 feet. You can have more than one lateral but each can not exceed 294 feet. I wouldn't take it to the limit. The number of laterals will depend on the diameter of the header and the amount of water you can deliver to the header from your distant source. Is 3200 feet a typo? That is a very long run. How are you going to deliver water to the header from 3200 feet away? You have to figure pressure loss per foot. First you have to figure your required flow rate. If you have a total of 600 one gph emitters then your required flow rate is 600 gallons per hour. From the pvc friction loss tables if you use 1.5 inch pvc the loss will be about 10 psi over 3200 ft. If you use 2 inch pvc the loss would be about 3 psi. With 1.25 inch pvc the loss would be about 23 psi. You need to know your source pressure and flow rate. You use the brown more expensive line because the runs can be longer. As noted above the brown 1/2 inch line with 18 inch 1 gph emitters is good for almost 300 feet. The maximum length of 1/4 inch line with 1 gph emitters spaced 12 inches is about 17 feet. I used the more expensive 1/2 inch brown line similar to your first image but I purchased it with 12 inch emitter spacing. If you use 0.4 gph emitters you would cut your required flow rate in about half for the same number of emitters. That would reduce the size of the required source pipelines. Then you run the system twice as long to get the same amount of water.