Things to Know Before Installing an Automatic Sprinkler System

August 28, 2010

It takes approximately  27,154 gallons of water to apply one inch of water to one acre of land.

After writing so many articles on lawn sprinklers, repair and maintenance, I was approached to write an article on things to know or consider before installing a new sprinkler system. This is not a ” How To” install a sprinkler system but what questions to ask yourself and a contractor prior to having a system installed.

It can be very difficult to judge one design/bid against another as no one irrigator will design a system exactly the same as another. You can limit the difference by requesting certain components or brands, but this may add to the difficulty as many companies will play off any differences between them. You might find it more beneficial to define performance and expectation over specific components.

  1. Watering Concrete: As a cost cutting method, some contractors may elect to spray water across a narrow walkway or sidewalk in lieu of boring under the concrete to set a head. If this is important to you, make this point clear: No or minimal watering side walks or driveways. Ask for examples for better understanding.
  2. Zones Designed Specific to the Needs: All lawns have micro climates where more or less water is needed. The contractor can use different heads and design methods to provide more or less water. Basically, you would not want a sprinkler head that is in the deep shade on the same zone as one that is watering in the full-sun; as the full sun area will require more cycle time than the shaded area. Additionally flower beds have different watering needs over turf. Segregating flower beds into their own zones will allow you to manage your water better. TIP: In the extreme heat of the summer, it can be difficult (and costly) to keep the turf green. For me, I go into survival mode, by reducing the watering time to just keep the turf alive. On the otherhand, since my flower beds are covered with drip emitters, I increase their duration.  It may save you a bit of water.
  3. Drip Line Emitters: Consider using drip or emitter lines for flower beds. This style of watering will bring the water to the plant roots without wasting water through the air. I installed drip line emitter style  in both the flower beds and parkways  over 3 years ago and have been very pleased with the results. TIP: They can be damaged easily, so you have to be careful when digging around them.
  4. Name Brand Components: If the contractor can not provide you with material literature, ask them to provide the name and model numbers of the major material to be used. Specifically: Backflow preventer, valves, sprinkler heads/nozzles, the controller and any additional ancillary equipment you may request.  Do some research on the internet regarding the models, performance and any customer complaint issues.
  5. Efficient water nozzles: If you have read any of my sprinkler articles you know that stream heads over spray heads do not atomize the water as much, putting more water on the ground and less in the air. Low Arc heads also increase efficiency. See Lawn Sprinkler Nozzles.

Irrigation Controllers Are a Subject Within Itself. Unless you request specific features, most contractors will provide you a “builders grade” controller. This is also the grade of controller you will find at the orange box store.  If you have read any of my articles, I am an advocate of the Sprinkler Warehouse as they provide multiple types, styles, models and brands of all sprinkler supplies. Look at the site for a controller you like or features that you find necessary.

  1. Basic Controller: Basic controllers will provide a minimum number of stations to support the number of sprinkler zones installed. Additionally they will include timed events, day of week, time of day type stuff. Most basic controllers can accept an  external rain gauge. The controller should include a 9V battery backup to ensure the clock remains current.
  2. External Sensors: Even basic controllers will support external sensors and typically they do not have to be the same brand. So if you find a sensor you like, it will usually state it will work with any basic controller. The most popular sensors are rain, wind and freeze.  In some municipalities, rain/freeze sensors are required by code and you can receive a citation for the system being active during those times. Additionally, time of day has become an issue, but that can be easily controlled by the clock settings on the basic controller. If your municipality requires a rain/freeze sensor, have it included in the contractor bid.
  3. Intuitive controller:  To go to the next step, you may consider a controller that uses weather data to determine watering cycles. Some Wifi connected controllers simply use the collected data to just turn the unit off in anticipation of rain or freeze. However, some can be more intelligent and actively manage the water distribution to the point of deciding when and when not to water. There are a lot of new Wifi enabled devices out there and at this point I dont have a specific recommendation, so you will just have to read the feature set as described by the manufacturer. So far, I am a fan of the moisture sensor over the weather feature as I see the sensor measurement as being real-time over the weather report still being a bit of a speculation. Many times equipment manufacturers add features to controllers with more zones. You may have to consider a controller with a greater number of stations than required to get some of the feature sets. Ask the contractor if they have any form of reasonably priced moisture content sensors as part of their package.
  4. Test Function: May not be found in the very basic controllers but it is a valuable tool. It is basically an additional run program that is based on very short watering sessions. Setting the Controller to “TEST” will allow you to walk the yard while the sprinklers are running through all the zones. This allows you to visit each head to identify any problems that need correcting.  An enhanced feature is “Remote Control”. Using a hand-held transmitter, the user can turn on/off sections without returning to the controller. You may find this desirable if you have a very large lot, otherwise the test feature will probably work fine. This is one of the big selling features of the the Wifi enabled controllers as you can use your phone to activate the system.
  5. Water Usage: How ever you spin it, your water usage will dramatically increase. Even with a good efficient system, you will be watering more thoroughly than in the past. Managing your system electronically will ensure the most efficient use of water.

Here are some things you need to know or ask yourself before you start the process.

  1. Water Usage: It takes approximately  27,154 gallons of water to apply one inch of water to one acre of land. No mater how you cut it; using an automatic lawn sprinkler system will increase your water bills. Using the number listed above as the basis;  that works out to about .623 gallons of water per square foot. So; take your property lot size (ex. 50×100=5000) minus the square footage covered by the house, driveway, sidewalk and garage (ex. 1500H + 800D + 200S + 400G = 2900 sq ft.) Property size minus non-landscape surfaces  equals area to be watered. (ex. 5000-2900=2100 sq.ft.). Multiply .623 times the remaining square footage (ex. 2100 x .623= 1308 gallons of water to achieve 1″ per watering cycle). Climate and rainfall will impact the amount of watering but if you figure watering 3 times per week, it would work out to 15,699 gallons per month figured at 100% efficiency. Most typical sprinkler systems are 50-80% efficient (adjusted to 23,548 to 28,258 gallons per month). It all adds up.
  2. Existing Water Meter: Most of the time, sprinkler systems are installed using the existing water meter as the cost of a new meter can cost over $500 to have the city install one.
  3. New Water Meter: Because of the initial cost, most people will use the existing meter, but consider these facts as part of your decision: 1)Many cities calculate the sewage charges in your water bill  based on water used, even though they may provide a summer time allowance, it may only be for 3 months. Here where I live, it is not uncommon to use the sprinklers 9 months of the year. 2) Older homes with 3/4 in meter may not provide your system adequate water pressure, 3) Using a larger meter with higher pressure may actually reduce the amount of equipment required for the system. Additionally,  pressure and volume will impact the amount of zones and heads needed to water the property. In the initial evaluation, the irrigator will validate the meter and the water pressure. If it is border line, they will normally recommend an upgrade or an additional meter. You may also ask if upgrading the meter to the next larger size will impact the bid in a way to reduce his cost. This may come into play especially with large properties vs. small lots.
  4. Sprinkler Head Styles: If you have a small residential city lot, expect the  bid to include pop-up style of heads. If your property is over 1/3 of an acre expect to see a mixture of pop-up and rotary or oscillating heads. Typically, properties with open landscape (large turf areas) will be designed with head that can throw water further than 15 feet. This saves water and material. TIP: It is acceptable to have different type heads in a system but not acceptable to have different type heads in the same zone.
  5. Warranty: Ask for at least a year, but two is better. Most any problem will surface in the first two years.
  6. Spare parts: Honestly; sprinklers require a lot of maintenance to retain peak performance. Damage from lawn mowing  is the biggest culprit. Using the exact same heads and nozzles will ensure  peak performance. Most contractors will be using a different grade of sprinkler head than found at the orange box store. Ask the contractor to provide extra sprinkler heads, nozzles and risers (ask for minimum of 1 of each or 10% in heads/nozzles/risers used in the system). Some where around 10-20% extra sprinkler bodies and 2-3 each of the different nozzles. Also ask for at least one extra sprinkler valve for every 10. Whether you do the maintenance yourself, hire the same contractor or someone else, this will guarantee that you retain the integrity of the original design.

Assuming you are dealing with a reputable licenced irrigator they will appreciate your preparation and gained knowledge.. However, some of the questions and requirements provided may not set well with others. That alone, will help in weeding out the undesirables.

If you are looking for more information or greater detail, take a look at this site as it does a great job of explaining Efficient Irrigation.