How to Get Your Sprinkler System Design Reviewed Before You Buy Parts

Why a second pair of eyes pays off before the trenching starts

Every spring the same post shows up in lawn forums: a photo of a pencil sketch, a list of heads somebody found on sale, and the question "does this look right?". The first replies are almost always questions back. What's your static pressure? How many gallons per minute do you get at the hose bib? How big is that back lawn, really? Without those numbers, nobody can say anything useful.

The time to get a design checked is before you buy parts and before you rent the trencher. Moving a head on paper takes ten seconds. Moving it after the pipe is in the ground means opening the trench again. On the jobs we follow, the expensive mistakes are rarely installation mistakes. They are design mistakes discovered when the system is finished: the last rotor on the zone barely clears the grass, or the shrub bed drowns because it shares a valve with the lawn.

This guide covers what to prepare so a review is worth something, the mistakes an experienced eye catches in a few minutes, where to get a design checked in the US, and how to send it so the other person can actually fix it. The last part is about the moment when advice is not enough and it makes more sense to hand the job to a contractor.

The numbers a reviewer needs from you

A sprinkler design is a budget: the water you have against the water your heads use. Whoever reviews it needs both sides of that budget, otherwise they are just looking at a drawing. Collect these before you ask anyone.

Static pressure comes from a cheap pressure gauge threaded onto an outdoor faucet, with every other tap in the house closed. Neighbors on the same street can read very different values, so measure yours rather than trusting a typical figure. Working pressure, with water flowing, is lower and is what the heads actually see. We explain how to measure both, and why static pressure alone can fool you, in /enHow to measure water pressure for irrigation.

Flow comes from the bucket test. Open the faucet all the way, time how long a 5-gallon bucket takes to fill, then divide 300 by the seconds to get gallons per minute. If it fills in 25 seconds, you have 12 GPM. Measure at the faucet nearest the point where the system will tap in, because a long run of small pipe inside the house can cost you a couple of GPM.

Then the yard itself, to scale. Graph paper with one square per foot works; so does a satellite view traced to scale. Mark the house, driveway, walks, trees, beds, the water source, and anything that must stay dry. Note the height of hedges and shrubs: a 4-inch pop-up cannot spray over a 3-foot hedge, and that single detail changes which heads belong where.

• Static pressure, and working pressure if you can, in PSI.
• Flow in GPM from the 5-gallon bucket test.
• A scaled plan with the water source and meter marked.
• Zones by plant type: turf, shrubs, flower beds, vegetables.
• Soil type (clay, loam, sand) and sun or shade per area.
• Obstacles: trees, walls, walks, windows that must stay dry.

Five things a reviewer checks first

With those numbers on the table, anyone who has installed a few systems goes straight to a handful of points. First, the flow budget per zone: the GPM of every nozzle on one valve has to fit under what the supply delivers, with a margin. If a zone asks for 14 GPM and your bucket test said 12, the heads at the end of the line will not pop up fully or will throw half their radius.

Second, spacing. Heads should be placed head to head, meaning the spray of each one reaches the next head. A layout with heads spaced at one and a half times the radius leaves dry stripes that show up in July like a barcode. The rules, and the cases where you can stretch them, are in /enSprinkler Head Spacing: The One Decision That Decides Whether Your Lawn Goes Brown.

Third, mixing what should not be mixed. Rotors and spray heads on the same valve apply water at very different rates, so one area floods while the other stays dry. The same goes for turf and shrubs, or shrubs and a vegetable garden: they need different amounts of water, and one of them will always be over- or under-watered.

Fourth, impossible throws. The radius in a catalog is quoted at a specific pressure; below it the throw shrinks. A rotor drawn at its full catalog radius on a supply that barely reaches the rated pressure will fall short. Fifth, edges and corners: arcs that water the house, the driveway or the street, and lawn corners that no head reaches. A longer list of design errors to avoid is in /enIrrigation Design Mistakes: A Pre-Installation Checklist to Avoid Dry Spots and Soggy Zones.

Where to get a sprinkler design checked in the US

The best free place to start is r/Irrigation on Reddit. It is a community for professionals and non-professionals alike, the rules ban advertising, and threads about system design, valves, zones and controllers come up every day. A post with your PSI, GPM, square footage and a link to the design often gets answers from contractors who install systems for a living, sometimes within hours.

Whoever reviews your design, check local rules yourself before you finalize: many US jurisdictions require a backflow preventer on irrigation systems, and some require a permit or a licensed installer for the connection to the water supply. Your local building or water department is the place to ask.

Local plumbing and irrigation supply shops are the most underrated option: many will check or design a system for free if you buy the parts there, with the obvious catch that your parts list will follow their shelves. A landscape architect or irrigation designer is the paid route; worth it for large or sloped properties, overkill for a typical quarter-acre lot.

Forums and Q&A sites cost nothing and, with a good post, work surprisingly well. The catch is time and consistency: answers come over days, and quality depends on who happens to read your thread. Treat product advice in older threads with care.

How to send your design: photo, PDF, or a link they can edit

A phone photo of a pencil sketch is better than nothing, but it forces the reviewer to guess dimensions and to describe in words where a head should move. A printed PDF is easier to read, but it is still a picture: to suggest a change, someone has to redraw it.

That is why we added share links to SprinklerMap. In the Settings menu, right under Print, the Share button creates a link to the yard you have open; the chain icon in My Gardens does the same. Whoever opens the link gets, after signing in, a copy of the yard in their own account: the layout, the excluded areas, the heads, the soil type, the water pressure and the parts you picked in the components list, all in feet and GPM if that is how you work. They can move a rotor, swap a nozzle or split a zone, then send you their own link, and you compare both versions side by side instead of decoding a forum reply.

Your design is never touched, because everyone works on their own copy. The link shows the project as it was when you created it; after you make changes, tap Update link. You can disable it whenever you like, and copies already made stay with the people who received them. The drawing carries no GPS coordinates and no street address, so posting it publicly does not reveal where you live.

One tip for the post itself: put the numbers first (PSI, GPM, square feet), then the link, then a specific question. "Does this look OK?" gets vague answers. "Is zone 2 under the 12 GPM I measured?" gets useful ones.

When advice is not enough: handing the job to a pro

Sometimes a review tells you the job is bigger than you thought: a sloped yard, a well pump that needs sizing, six zones and a controller to wire, or a local code that requires a licensed installer and a backflow preventer. Or the opinions you collected contradict each other and you cannot tell whom to trust. That is the point to decide between doing it yourself and hiring someone, and the design you already drew is worth more than it looks.

The usual request to a contractor is vague: "how much to put sprinklers in a 5,000 square foot lawn?". The answer is just as vague, or it only comes after a site visit. With a design you can say exactly what the job is: area, number of heads, feet of pipe, components and an estimate of labor hours. A contractor can tell in a minute whether the job fits and roughly what it costs, and quotes start from the same baseline instead of a guess.

In SprinklerMap this step is called Find a professional, and it sits in the components list under the parts summary. You choose what to share (the shape of the area with the heads, the parts list, the estimate of hours and budget), you enter only your city and when you need the work done. We never ask for your street or house number: what we do not collect cannot leak.

The whole model is built to avoid the experience anyone who has filled out a lead form knows well: you leave your name and phone number, and for days you get calls from companies you never picked. Here your name, email, phone and address are never passed on. Requests are visible only to professionals we verify by hand, and only when your city falls inside the radius they serve and your yard within the size they take on. A contractor who is interested says so; under My requests you see who stepped forward, with their details, and you decide whom to contact. Contact always goes from you to them.

Requests also do not linger forever. They expire after 30 days if you picked "As soon as possible" or "Within a month", after 90 days for "Within three months" or "I'm in no rush"; you can renew them up to three times and close them whenever you want. The network is young, but professional sign-ups are growing steadily: there are verified SprinklerMap professionals on three continents today, in Europe, North America and South America. While your request is open, professionals who join in your area later can see it too.

Checklist before you ask for a review

If you want a reminder, this is the order we follow when someone asks us to look at a design. If any point is missing, fill it in before you ask: it saves a whole round of questions and answers.

• Pressure and flow measured at the faucet the system will actually use.
• The yard drawn to scale, with walks, driveway, trees and the meter.
• Turf, shrubs, beds and vegetables on separate zones.
• Each zone fits under the measured GPM, with some margin.
• Heads placed head to head, with no arcs on the house or street.
• The design shared so a reviewer can edit it, not just look at it.
• If the job is too big, the components list ready for a precise quote.

Sources

Pages read on October 23, 2026.

1. Reddit, r/Irrigation (community for irrigation professionals and homeowners; advertising not allowed).

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