We had some major grading done at our house which made the existing, poor quality lawn a bunch of bare topsoil. I used a powe rake, removing rocks, roots, etc. I planted a good blend of seed from our local mill, and blew straw to protect the seed while it germinates. The prep work was great. This isn't the first lawn I've done, so I believe I was setting myself up for success. Now the disaster: there is terrible water pressure at my house. Sprinklers that should be shooting a 100 foot diameter are going as far as 20 feet. This wouldn't be such a bad thing, but I planted over an acre of grass seed. What is the likelihood of the grass coming in without watering it or maybe doing a good soke once a week with rain water substitution hopefully twice a week?

New seed needs to stay damp and not dry out to properly germinate.

Get a pump for your irrigation system.  It sounds like you need something that will give you at least 50-60 psi at the nozzles.

This is the first time I'm hearing of this. Can you lead me to something you're talking about? Is it an easy installation?

What sprinkler heads are you using?  Go to the manufacturer's website and see what operating pressure they need.  This is what you will need at the nozzle. It will also tell you the gpm that each head uses.  Count up the number of heads on the station that has the most heads and add up that many gpm's.  That is the minimum flow that you will need.  

 

What size water meter do you have?  What is the pressure at the meter? The difference between nozzle pressure and the pressure at the meter is the amount of boost you need from the pump. What size mainline do you have?  Is it capable of delivering the gpm's that you need?


Install the pump between your backflow device and irrigation valves.  Your controller should have a pump start on the terminal strip that your valve control wires are connected to.  Run a wire from it to a relay.  The relay will need to be connected to a power source that is the same as the pump (120v, 240v...).  When the controller comes on, your pump will come on.

I have a variety of sprinklers going. All are rotary/orbital in their spray patterns. Some are designed to cover 7,800 square feet and other 5,000 square feet. They all seem to be performing the same right now regardless of sprinkler, hose length, etc. My well pressure is reading around 45 PSI. I'll have to try and get the other info you requested. It seems I can run 3 sprinklers right now which cover about a 40 foot radius each. I've been out here 4 hours now and have about 3/4 of the "grass" covered. Unfortunately, it looks like I didn't soak it long enough as the initial areas are starting to dry already. I penny pinched and cheaper out on top soil...probably not the wisest move but time will tell.

Your sprinkler system design is all ate up. Who designed it? Were any psi or gpm measurements taken?

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I don't have a sprinkler system installed. Watering consists of several hoses and movable rotary sprinklers that get temporarily spiked in the ground.

In your OP you said you had an acre of seeded lawn.  That is almost a football field.  Watering it by dragging around hoses and a movable sprinkler head is very time consuming and inefficient.  You should get a sprinkler system.

 

Multiple sprinklers are dropping the pressure to much, so pretty much this.

Even if you don't get a proper sprinkler system installed, running a setup with 1" PVC would be an improvement over hoses.

Even if I run one at a time, the water pressure is still terrible. I have 1" poly that was ran to a yard hydrant and there is little to no increase in pressure comparing it to a hose bib on my house.

You stated earlier that your well pump provides 45 psi.  The size of the poly line will not increase the pressure.  There are only 2 things that increase pressure-a pump or gravity.

 

You also stated that your sprinkler heads spray in a 110' diameter.  Most of those heads require 50 psi or more at the nozzle to operate properly.