pressure increases with additional flow

I've looked all over for a solution to this one. New house. First pump. No pressure tank. Three zones on my pump. Two go to sections of the lawn and work great. Plenty of pressure. Third goes to a garden hose connection. The garden hose only has pressure when one or both of the lawn zones are spraying. If the lawn sprinklers aren't on, there is only a trickle to the garden. I would like to water the garden more often, but need to overwater my lawn to use that zone. What sort of pressure Bermuda Triangle am I stuck in here. Common sense seems to say the exact opposite shoudl be happening. I get less pressure with less water to the other lines.

Also, I have city water too. Can I attach it to my pump to 'backflow' and prime it, or will that play havoc with the pump.

(Shallow 12-13 foot irrigation well. New pump. No blockages.)

Thanks. Any advice is appreciated.

Your irrigation timer is also what is turning on your pump. There should be no water coming to the faucet at all, if the sprinklers are not running. You could use a manual switch to turn on the pump when the sprinklers are not running. If you do this you should not have a faucet or a spray handle on the end of the hose. If someone closes off that line while the pump is running, the pump will burn up in a matter of minutes.

You could also use a pressure tank and pressure switch to control the pump. Then when you turn on the faucet or sprinklers, the pump automatically comes on. When you turn off the faucet or sprinklers the pump goes off. However, you will then need to make sure your irrigation system puts out enough water to keep the pump from cycling, or use a Cycle Stop Valve to do that for you.

pressure

Sorry. Didn't give you enough information. What I am calling zones are actually just three pipes splitting off from the pump outlet. Two to underground lawn areas, one to a spigot. I have soaker hoses throughout the garden from the third outlet, so there should be no problem with the pump being blocked and overheating since they are always open. Pump is new and puts out a TON of water. I don't know what the flow is, but there is a two inch prime pipe (I assume that's what it is called since the past owner told me it was and it seems to work) that shoots water a good 8 feet in the air when things get going and it isn't capped. All connections are opened or shut by hand. No clogs. This is a really basic system with no timer, pressure tank or anything else. Not an internal pump, pressure. I was told it is a 12 -14 deep well. Just open a valve, prime the pump and turn it on when I want water. Both sprinkler lines can be working and there is no noticable decrease in flow from any of the THREE outlets. If one or more sprinkler lines are not going, I get just a trickle to the garden, yet any one of the sprinkler lines can be running alone and all is fine. One unusual thing with the garden line. It goes from a one inch line to a two inch line for about 10 feet along a wall, and then back to one inch. Could there be some bizarre pressure 'thingy' going on due to this? Thanks again for any help you can offer.

There is something going on here that would be obvious to the trained eye that your not able to tell this Forum about. Your going to have to take some pictures or find a better way of explaining what you have.

You haven't even told us what kind of pump you have.

bob...

Sounds like you just need to put a ball valve on both of those lines going to the yard sprinklers.

pressure

I really appreciate the responses. Speedbump is right. Need to give more information than I have. I'll get the pump info tonight and a photo.

thank you again,

Eric

In case anyone cares

Figured out my problem. The faucet that would only work when other zones were on was tiny. Looks like some ancient 1/4" or smaller original. (1920's) Pump must have just been spinning. Replaced all the piping and put in water to garden. Increased all faucets to 3/4 and 1". Everything works great.

Thanks again for help. It took three days, $300 and a LOT of digging, but I've a system that works and that I understand.