# Will combining two irrigation pipes increase pressure

Using irrigation water out of a 14inch pipe with about 115ft drop from a pond on a hill. We use it to water lawn/garden on preexisting traditional lawn sprinkler system.

Currently have a Amiad Sigma filter attached to a 2inch sadle to the side of the 14 inch pipe.

When the farmer below us isn't using water out of the 14inch pipe we have about 50PSI inlet to the filter. Ideal for thr sprinkler system. When the farmer is using water we have 10-30PSI. Not enough for the sprinklers.

To increase pressure my thought process is inlet to the filter needs to be as big as possible. It's 2inch from the sadle to the filter, the largest the filter can accommodate already.

Or The farmer needs to use less water. Not feasible.

Or turn more of our water shares down the 14inch pipe via the pond at the top of the hill. The farmer is already using more than his allocated shares. Figure he'll just use more of ours if we add them down the 14 inch pipe.

OR the question at hand could we connect another 2inch pipe to the inlet of the filter to increase pressure? There are two 2inch sadles on the side of 14inch irrigation pipe. We only have one hooked to the filter. Would tying two 2 inch pipes togethe, then to the filte, increase pressure?

Other wise looking at a pony pump, digging our own pond below his, or putting a sadle at the bottom of the 14inch pipe rather than the side.

115 feet of head is almost exactly the 50 PSI you get now, and you're measuring the inlet side of your filter. When the pressure there drops due to the farmer's water use, that's all the pressure you have in the big pipe at that point, due to friction head loss from the farmer's water flow. Which means adding a second input or moving the input will have no useful effect. You could Tee off a full 14" pipe and you'd still have 10-30 PSI when the farmer is drawing water.

Moving the saddle from the side of a 14 inch pipe to the bottom (so, 7") will make a difference of about 1/4 PSI, for example.

You either need your own, non-shared pipe from the pond above, or you'll need to pump. If you dig a pond below the existing pond, you'll lose some pressure, as you'll have fewer feet of head. But your own pipe (whether to the current pond or your own pond) will not be affected by the farmer's use of the 14" pipe. Unlike a pump, a pipe, once purchased and installed, costs nothing to run if you have gravity head from your water source.

Something ballparking 7,000-10,000 gallons per minute are flowing to drop the pressure in a 14" pipe at your 2" take-off to "10-30 PSI" from 50 PSI.

Depending on the length of the pipe to the pond (not just the head) and the flow rate of your water use when sprinkling, your own pipe will almost certainly need to be larger than 2" in order to provide adequate pressure, since the 50PSI you are happy with is essentially static (your tiny flow in a 14" pipe means essentially no head loss from the pond to your takeoff point.) There are irrigation calculators to help sort out how big, when you have details like your own flow rate, the length of the pipe, and the new head if going to a lower pond .vs. your required minimum pressure.

In theory having more flow will increase pressure.

Adding the second 2 inch source should do this. However this is also dependant on gravity, so the solution I would recommend is having the two 2 inch pipes flow into a 3 inch pipe. The sprinkler system can feed off the 3 inch pipe.

Place 2 inch filters,in the lines feeding the 3 inch pipe. 3 inch pipe and fitting are available, but not at most home or hardware stores. They can be ordered online or try your local plumbing supply.

Or; get a pump and forget all the extra pipe and fittings. Then you control your irrigation, because you are not dependant on just gravity and who else is using the water.