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Recommendations for new sprinkler system?

We have a big yard -- 1.1 acres, much of it grass. Our lawn looks awful with numerous bare patches. One of the problems is our outdated sprinkler system. It is has rotary sprayers that have been replaced over the years with many different kinds and brands of heads, and there are many places that no sprinkler heads can reach. I'd like to replace the whole thing with a new system, preferably with stationary heads. This is one project we won't try to do ourselves, but I'd like to be armed with the TOH staffers and readers' extensive knowledge before I contact a landscaping company for their recommendations. Since our original system with put in sometime in the 1980's, I'm sure there's something out there with better coverage and better electrical and water efficiency. We also plan on turning some of the grassy areas into something else (like expanding the driveway) so that we have less to water. We live in the Denver metro area. Thanks in advance!

Re: Recommendations for new sprinkler system?

Here are a few tips that may help you. Covering such a large expanse of lawn with stationary pop up heads is probably not very practical. Rotary heads will work great if you follow a few simple rules. You want to invest in quality heads. I use Hunter myself, but there are plenty of other good products.
You need head to head coverage. Let's say you have grass that is 60 feet across. You have heads that spray 30 ft. Do not put one head at each corner. Although both sprays meet in the middle and are "covering" the lawn, it is not adequate. You need a head in the middle. Each head then hits the other with it's spray giving you quality coverage. Same thing for you pop ups.
Second, if the corner heads are rotating 90 degrees and the head in the middle is rotating 180 degrees, since it is traveling twice as far in the same time, the middle head needs to put out twice the water per minute than the corners. If the corner heads are 1.5 gal. per minute, the middle head must be 3 gal. per minute for even watering.
Third, never mix rotary heads and pop ups on the same zone. The pop ups will put down much more water per minute than the rotors, causing uneven coverage and likely dry areas and soggy (fungus) areas. Nothing but rotors one some zones, nothing but pop ups on other zones.
Use rotors for large expanses of lawn, use pop ups for smaller areas, around walkways, flowerbeds, etc.
Hope these tips help.
Best, Mark

Re: Recommendations for new sprinkler system?

I would also look at using a type of grass that requires less water. We have areas of zoysia in our lawn which needs less water. I hope it eventually takes over the entire lawn area. I don't know if it would do well in the Denver climate or not.

A. Spruce
Re: Recommendations for new sprinkler system?
advrem wrote:

Here are a few tips that may help you.

Lot's of excellent info!

First and foremost, plan out your landscape, including your driveway expansion, flower bed width and watering needs, all tree locations, specimen spots that may need special watering or lighting needs, and overall grass layout, etc. If you plan to build a garden shed with water and/or electrical needs, now is the time to install those lines and conduit. If you need to install a drainage system for either the yard or downspout runoff, do it now. If you plan on installing driveway lighting, coach lights, delivery bell, security camera, etc, now is the time to consider laying conduit for those future projects.

As to the sprinkler system in particular, again, with the above plan, you can start determining the number of sprinkler heads and zones you'll need to cover the entire area. The number of heads will be determined by your water pressure, don't assume that you can just put X amount of sprinkler heads on a single line and be good. It is better to use fewer heads and run more lines than the other way around. Too many heads will drop the overall line pressure to the point that you won't have adequate coverage. The number one key is to have full head to head overlap of all sprinklers, regardless of the style you use. For large open spaces, impact sprinklers work the best and have the largest coverage pattern. For smaller intricate areas, pop-ups work great. Rotary sprinklers were mentioned earlier, and it bears stating that there's a difference between a rotary and an impact sprinkler. A rotary is kind of a cross breed between a pop up sprayer and an impact sprinkler stream. I don't personally like them or think they work all that great. An impact sprinkler is the one that has a swing arm that bobbles in and out of the water jet which causes the sprinkler to turn. The system should have it's own shut off from the main source so that it can be turned off for maintenance or winterization.

As previously mentioned, DO NOT combine impact and pop-ups on the same line. You also DO NOT want to combine flower beds with lawn areas. Keep in mind that lawn sprinklers can be chosen and adjusted to overspray flowerbeds that are better watered by broad cast than point watering. You may also want to future for hose bibs at outer corners of the yard, rather than trying to drag hoses to far off places when needed.

And lastly, I've always installed risers and sprinkler heads directly onto the sprinkler lines. Having had to replumb and redo a number of poorly conceived systems, I've come to realized the wisdom of using what's known as silly pipe, which is a flexible ABS extension from the sprinkler line to the sprinkler head. This allows for fine tuning sprinkler locations as well as being able to bury the lines deeper if necessary. Another benefit of using the silly pipe is that it will allow the majority of the sprinkler lines to be placed at the edge of the grass, in the flowerbeds where they can be accessed for repair or system alterations if necessary, without disturbing the grass.

Sorry for the long post, but this is a topic that is not easily covered with a few sentences.

Re: Recommendations for new sprinkler system?

Thanks, all! You gave me excellent suggestions. Now I can talk to the landscape contractor somewhat intelligently!

Re: Recommendations for new sprinkler system?

The city where I live requires a backflow prevention device on the line between the water meter and the zone valves. They also require that the device be tested annually.

There are two types that are approved for use here: atmospheric vacuum breakers which are mounted above ground, or double check valves which can be mounted in an underground valve box.

Where you live they may not be required but, if your sprinklers are supplied by a potable water system, it's a "must have" item to protect your health. Without the backflow prevention a busted water main, a maintenance shutoff, or a failure of a well pump can create a negative pressure (vacuum) situation and suck contaminated water back into the potable lines from the sprinkler system. This is a "bad thing."

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