Seasonal Reminder – Lawn Sprinker Tuneup

April 5, 2016

If you are a follower of this blog, lawn sprinklers seems to be a regular topic. I get more hits on this one subject than all the rest. After reviewing  the current articles I found that I lacked a straight up, “seasonal tune up” article. So, for this weeks post I am going to walk through a methodical process of checking your sprinkler system. Generally speaking this is about a system that is designed correctly and  working properly.  I typically do this at the beginning of the watering season then again in mid-summer.

Material/Tools Needed:

  1. Spare sprinkler bodies: You should normally keep some extra sprinkler bodies that resemble the product that was installed with your system. Having identical sprinkler bodies will keep replacement and repairs simple.
  2. A handful of various sprinkler nozzles: Even though there may be several types of sprinkler heads (pop up, rotary or impact), it is important to have extra copies of the same nozzle that are being used in the various zones. Even though many home centers prefer to sell you the sprinkler body with the nozzle, having them as separate items will save you time and money.
  3.  Sharpshooter Shovel:  This particular shovel works well when working on sprinklers as you can dig around a sprinkler without disturbing too much dirt. Dirt and dirty water  is the enemy when it comes to working on sprinkler systems.
  4.  Sprinkler flags: You will probably have to buy these in a pack of 100, but it will be less than $10. You will use these to mark sprinkler heads that require attention.
  5. Screwdrivers: 1 small screw driver, 1 medium screw driver (flat and Phillips head style). These will be used to disassemble nozzles and some heads.
  6. Dental tool: Something like this link will work; these can also be found at the Orange Box store. It is very common for sprinkler nozzles to capture small pebbles that will lodge in the nozzle disrupting the sprinkler spray pattern. You will want to pick out the debris without damaging the plastic.
  7. 1 pair of medium-sized Channel Lock pliers: These can be used to adjust, tighten and loosen the body of the sprinkler head especially if your hands are wet.
  8. 1 pair of medium-sized vise grips: Used as a way to extract nozzles from pop-up heads by lightly holding the nozzle riser exposed. Never use a lot of pressure as you can easily damage the sprinkler head.
  9. WD 40 Lubricant Spray: Used to lubricate various parts that are supposed to move or react to the water pressure. WD40 is a fish oil based product and should not damage the grass.

SPRINKLER TESTING PROCEDURE:

  1. Activate the test sequence in the Sprinkler Controller: Most controllers have a test function that allows you to run the system in short intervals. If you can choose the time limit, set it to two minutes. If your controller does not have this function, you can have a friend turn the sections on one by one. TIP: If you have to do this manually, find some walkie-talkies to communicate with your partner.
  2. Find the first zone that is running:  Carrying your sprinkler flags, walk around and through the zone that is running, looking for the six items mentioned below. Use the flag to identify problems. However, try to realign the heads in this first sequence while the zone is running. Use the Channel Lock to grab the body to make adjustments.
  3. Repeat #2 for all the zones: I find the sprinkler flags really help, cause you can go directly back to each problem once you have made it through the entire system.
  4. Repair, replace  or adjust the heads as required: One of the most  important elements of sprinkler repair is to avoid introducing dirty water into the system. The dirt will make its way to all the downstream head and clog them up. If you find a broken head or pipe within your inspection, you may have to clean all the nozzles (see #2 below) in that zone.
  5. Run the test sequence again: As a final step, run the system one last time to ensure that everything is operating to your expectations.

Common Problems and Solutions:

  1. Misaligned Heads: Heads that are used around the perimeter of a property typically use patterns less than “full circle”. These heads will require occasional realignment to keep them from spraying on a sidewalk, fence or house. You can  adjust  either the nozzle, neck or sprinkler body. Try adjusting to the right (righty tighty, lefty loosie). If you have to turn it to the left, try not to turn it more than a 1/4 or 1/2 turn. Turning the head too much to the left may cause the nozzle or head to disconnect itself (while under pressure), this may cause a guiser of water and will get you real wet.
  2. Dirty Nozzles:  If the pattern seems uneven or broken up. The nozzle is dirty. With the water off, grab the sprinkler stem and raise it as if it were spraying water. Use your vise grips to LIGHTLY hold the stem up. Remove the nozzle and pull the filter (with the dental tool or your finger tip). Blow through the filter and nozzle. If this doesn’t remove all the debris, use the dental tools or water to clean further. You may have to disassemble the nozzle completely to get the dirt out. If the filter was completely stopped up, turn the sprinkler zone on/off very quickly to flush the line at this point (with the vice grips in place). Reassemble the nozzle to the head and release the vise grips to let the stem return to the body. NOTE: The purpose of keeping the stem extended through this process is to avoid the opportunity for dirty water to enter the system.  
  3. Broken/Damaged  head: Besides the nozzle mentioned above, the sprinkler body can leak as well. This could be out the bottom, side or top. Sometime the heads can be rebuilt, but at this stage its best to just swap out the head with an identical body and nozzle. If it’s not muddy around the head, attempt to unscrew the complete body out of the ground. Without disturbing the dirt, re-insert the replacement head. If you have to dig it up, use the sharp shooter shovel to expose the  head down to where it connects to the next pipe. It’s best to dig the hole a bit deeper than the head. If water comes out, you do not want the dirty water to reenter the system as mentioned above.  Replace the head and the surrounding dirt.  This sprinkler repair  link has a video included that might be of help.
  4. Sprinkler heads do not recess into the ground after spraying: This is a very common occurrence caused by small dirt particles surrounding the elevated riser at the wiper seal of the sprinkler head after the water is turned off. Grab the head by the tip and spray WD-40 on the riser. Work the shaft until it moves freely. If that doesn’t clear it, replace the head  and rebuild the old one in the sink to get all the dirt out of it.
  5.  Heavy Running or Pooling Water: This could be associated with #3 or it could be a damaged pipe.  With your shovel, LIGHTLY remove the wet dirt, you do not want to cause anymore damage. Dig below the pipe or area to be repaired. Use a coffee can to remove as much of the water and dirt as possible. Make the repair as necessary.
  6. Weeping heads:  Occurs when system is off. Typically you will notice this on days the sprinklers are not running, or you find constant moist spots. Typically, you must disassemble the sprinkler valve and clean it.  Rebuilding the valve may be required as well.
  7. Draining sprinkler head: similar to #6, but usually happens with a head that is located lower that other heads in the zone. This is fairly normal and can be left alone. If it happens in a bad spot and you really don’t like it, you can add a lateral line drain to disperse the water.

 For more detailed information, take a look at these other articles I have written on the subject: Lawn Sprinkler Efficiency Part II, Lawn Sprinkler Efficiency Part I ,  Searching for Lawn Sprinkler Valves, Chasing Lawn Sprinkler Leaks; Finding Sprinkler Valves and Common Problems,Lawn Sprinkler Efficiency Upgrades Part II,  .



Finding a Lost Sprinkler Head

July 18, 2009

Lawn Sprinkler4Finding a lost sprinkler head can be a challenge, simple in concept but difficult if you don’t have a plan.  Sprinkler heads can fail to rise to the occasion when under pressure. The longer they fail to operate the harder they may be to find. 

Perform these items first:

  1. If available, look at the drawing used during the installation system, it may work as a road map in identify the general location.
  2. Look for an obvious brown/dry spot. Run the sprinkler, it may pop up but be clogged. If so, disassemble it, clean it, reassemble it, install it and you are done. If not, go to #3.
  3. If the entire zone appears to be weak, you may find water pooling. This could actually be a broken head or pipe as in this condition you are consuming way more water than the design.
  4. With the sprinklers running, look for mushy ground  and water pooling. The head may be working, but it is too covered up to rise above the grass. Use a shovel to work the dirt (carefully). It may pop up once the dirt around it has been loosened up.

Missing SprinklerOkay, that was the easy stuff, now it gets hard. Go to the Orange Box store and purchase some sprinkler flags. Place a flag at each known head. Measure the distances between the heads as shown in the drawing.  You should find an area that does not measure (in relative terms) like the other ones. Start poking around with a shovel (carefully) in an attempt to expose the head 

Still no luck? Using the same method described in Finding Leaks in Sprinkler Zones and Common Leaks. You will need to turn off all the heads in that zone. Let the water run, hopefully,  it will show up since you are concentrating all the pressure to the missing head. Check your meter and look for moderate movement in the meter. If you have no movement in the meter the sprinkler head could be capped or not there at all.

Still didn’t find it?  You may not have a head there at all and the design just did not cover it well. So you may consider adding a head if the zone can accommodate the additional water use.

You may also take a look at one of my other articles for help in the Lawn Sprinkler catagory.


Lawn Sprinkler Nozzles, Can Changing Them Make a Difference?

July 12, 2009

sprinklers-01   

Heavy misting of the sprinkler heads can result in as much as a 25% loss in water.    

New sprinkler heads and nozzles coming on the market are claiming sizable water savings, but how much water can you really save (if any)?  Stream sprayers are normally found only in orbital or rotary heads and are typically found in larger landscaped areas and can be spaced 20′ to 30′ apart. With an open landscape, these heads can water more ground with less water. Up until now, there have been few options for smaller residential properties other than traditional pop-up heads using spray type nozzles. Spray nozzles are designed for spacing limitation from 8′ to 15′ and as with any type water sprayer, there is a correlation between distance and trajectory or arc necessary to obtain the distance. The greater the distance, the greater the height of the arc to obtain the distance. Greater distance = greater misting.    

But trajectory alone is not the only culprit to misting. High winds, high pressure, evaporation and excessive overspray all contribute to the water loss factor associated with misting. This misting can account for a loss of 10-25%. It’s this misting factor (more characteristic of spray nozzles over stream nozzles) that contributes to a lower efficiency found with the spray nozzle.  And its the low misting factor found with the stream sprayer that makes for an attractive alternative.     

In an attempt to make automatic sprinkler systems more efficient, some manufacturers have created a stream type nozzle designed as a direct replacements for the standard spray nozzle (aka pop-up sprayer). If you have read my earlier posts on lawn sprinklers you know that pop-up type spray heads can lose 10% or more of their water spray to the wind and evaporation.   Before we look at the differences between spray nozzles and stream nozzles, lets consider the ways to reduce sprinkler misting. Some of these items can be readily addressed, some are design considerations.    

Standard Spray Nozzles: Standard spray nozzles atomize the water to equally spray or spread the water out in an even flow throughout their spray pattern. They are great choice for small residential properties as they provide good water distribution in a reasonable amount of time. Additionally they have many different nozzles to fit the various application requirements.   

012106_lwn_sprinkler02_dt   

  1. To much pressure: Optimally pop-up sprayers work best at 30 psi. High pressure can cause excessive misting.  TIP: To test the zone water pressure, you have to remove a head, replace it with a riser and thread on a water pressure gauge, then run the zone and check the pressure while the zone is spraying water.
  2. Don’t water during high winds:   This can be managed manually or you can add a wind anemometer to your sprinkler controller that will shut down the system at certain wind speeds. Even though we typically water in the night-time hours (to avoid excessive evaporation), windy conditions are as common during the night-time as during the day.
  3. Keep water spray output close to the ground: This can be achieved by designing a system where the heads are closer (such as 10′ apart compared to 15′ apart)  Spray nozzles with shorter patterns use lower trajectories, will atomize the water less and have less distance to fall to the ground.  This item has to be addressed during the initial design as shortening patterns in an existing system could be considered a “do over”. I designed and installed my current system prior to stream sprayers, I took this approach by using 10′ radii heads. The water stays very close to the ground when the system is running. Granted, it caused me to use a lot more heads and zones. If I were to tackle it today, the stream sprayers would not only impact my water  usage, but cut back on material and zones installed. 
  4. Deliver the water in streams not in a spray or mist: The more you atomize the water, the lighter it becomes, allowing the wind to cause the water to drift away and evaporate before it has time to absorb into the ground or plant material.
  5. Deliver water directly to the roots through drip irrigation.  Flower beds can be easily converted (assuming your sprinkler system has specific zones for flower beds). For grass and turf this is a bit more involved but plausible.  In my current system I created specific zones for the parkway and driveway. Using direct bury drip lines, I am able to keep the turf green with virtually no run off. This is another condition that would need to be addressed in the original design.
  6. Refer to the  Alliance of Water Efficiency, for additional water saving tips. 

Water Use and Abuse   

There is a fine line between efficient water delivery and adequate water coverage. Many irrigators will “over cover” an installation to ensure all the grounds receive adequate water. The Irrigator wants to over-saturate the turf to avoid brown spots or low coverage areas, as making a re-trip to install additional heads can be costly. Creating a system that uses excessive water will cause them less problems in the long run. But in doing so, there may be a high degree of waste associated with the design. Don’t get me wrong, the lawn sprinkler business is very competitive and most people won’t spend the money to get a system with high-efficiency. Since water is still cheap and fairly plentiful this methodology will be with us for a while. However, the purpose of this article is to attempt to make your existing system more efficient and if you have a decent design, you can make some reasonable changes that will not terribly affect the performance of the system.   

Lawn%20edge%20pop%20up%201Stream Sprayers: Stream spray nozzles provides multiple streams from the nozzle in the defined pattern (90, 180, 360 degree pattern). To provide adequate coverage, the streams spray in a rotation throughout the pattern.  The beauty of the stream type nozzle over the spray nozzle is it will project water similar distances without high levels of misting. However, based on their delivery you may actually have to run the systems longer to get similar watering results, but since they are more efficient, it will not negatively impact the system performance.  With the move toward greater efficiency, the stream principle has been introduced to traditional pop-up sprayer. Some manufacturers provide them as replacement nozzles, where others require you to change out the complete head. TIP: Look at one of your spray heads to determine the brand, go online to see if the manufacturer makes a replacement nozzle, don’t be surprised if your local orange box store does not carry them. I have used Sprinkler Warehouse for many of my sprinkler parts and speciality items.   

The Test Case: I created a model zone with 4 heads, 2-180 degree heads and 2-360 degree heads.  I used the Toro 570 model body as it can be equipped with either the spray nozzle  or retrofitted with the stream nozzle. Optimally, the comparison is based on a 30 psi rating at the head.    

In converting the system from spray to stream we need to match the pattern as close as possible. Since spray heads are a mature product, many patterns and styles are available, but with the stream nozzles, the available styles are still limited. With the Toro brand, the new stream nozzles are not a direct comparison in spray distances and the stream nozzles may have to be tuned to reduce the pattern to avoid excessive over-spray onto the sidewalk. But they were pretty close.   

Stream Spray Matrix

Spray Nozzles De-rated by 10%

   

Sprinkler Table2

Spray Nozzles De-rated by 25%%

   

 From a cost comparison, it is beneficial to be able to re-use your existing spray heads if at all possible,  as having to buy new heads as well as the nozzles will add up quickly. When you look at the water saved vs. the cost of the change, it did not prove out (for me) since water is still very cheap. However many municipalities tack on additional charges based on water usage, so it could make a difference for you. If you are interested in seeing how much difference it makes, take the water saved (listed in the table and calculate it against your dollar per gallon charges found on your water bill.   

Based on the results of the chart, here is my observations using the 10% de-ration chart.   

  1. It requires 86.72 minutes using the stream spray nozzles to provide the same precipitation value as the spray nozzle provides in 60 minutes.
  2. Even though it requires 26.72 minutes more, the stream sprayers use 393 less gallons
  3. Factoring in a 10% misting factor, the stream sprayers use 5.77% less water or 471.63 gallons of water per month.

At a 25% deration the numbers are a bit more dramatic as you could save over 1700 gallons of water per month.   

Conclusion:    

  • Consider using the stream sprayers in a new design as you can use less heads, less zones, less pipe, less fittings as well as less water. 
  • Convert existing sprinkler zones to stream sprays where high wind is normal or misting is excessive.

Recommendation: If you choose to replace your existing nozzles/heads, change one zone at a time. Let it run through part of the season, compare the results by looking at your turf . For proper watering don’t mix spray nozzles with the stream nozzles in the same zone. To obtain an adequate amount of water similar to the spray nozzles zones, the watering time may have to be increased on the stream nozzle section.   

To see the entire series of lawn sprinkler articles go to Lawn Sprinkler tab on the HomeownerBOB web page.   

Good Luck   


Seasonal Reminder – Summer Household To Do List

July 5, 2009

100_0497Summer is Here!!!  Its been close to 100 degrees most of the week, and it could be that hot till Labor Day. This seasonal reminder is more about making sure everything continues to work well through the stress and strain of the summer months more than anything. If you live near me, getting these things done before 10 AM in the morning is the best time of the day, otherwise you may wait till after 6 PM or so.  If you need details on what to look for or what to do, click on the link (if there is one) and it will take you to the post that was written on the subject and provide more detail.

  1. Heating/Cooling-Air Filters: If you live in a dusty area and/or have been using your air conditioner a lot, inspect you filter and change it if it has noticeable build up from your spring change out. 
  2. HVAC Outdoor Unit: We did this in the spring and it’s good to do it again as vegetation has been growing through the spring months. Get your garden trimmers out and trim away any vines or growth away from the  outside condenser. You should have 18″ to 2 100_0233feet of clearance around the unit. Airborne particles generated by the blooming of trees and bushes can easily show up around the air conditioning condenser. Take your water hose and wash down the outside coils. Check the condensation drain that comes from the air handler in the house. Ensure that it is clear of obstacles or debris by pouring water through it.
  3. Water Leaks: Check all water fixtures and toilets for leaks. Inspect fixture drains for water puddles or loose joints in the traps.
  4. Lawn Sprinklers: If you read my weekly posts, you may notice I have been writing a lot on lawn sprinklers. This subject has been getting the most hits and questions so I have responded by writing more articles on the subject. Even though we performed this maintenance during the spring, yard work and vegetation growth can cause some additional sprinkler maintenance. Exercise the system. Look for excessive water traveling down the driveway or sidewalks. Inspect the sprinkler heads, look for blow-by, odd spray patterns, missing heads, pooling water and brown spots.  Replace or repair the heads. Chasing Lawn Sprinkler Leaks is the first of the series and covers the inspection, leak detection and repairs in more detail.
  5. 100_0503Exterior Inspection:  Walk round the house, look for bird and wasp nests, as well as locations that rodents might be using to get in the house. Use caulk to re-seal  any breaches in structure that may be an entry point for rodents or bugs.  They are all looking for cool locations and possible water.
  6. Interior Inspection: Flush kitchen and bathroom sinks with scalding hot water for approximately 3-5 minutes to clear out any build up.
  7. Appliances: Use a hand held vacuum cleaner to clear the dust bunnies from the vent at the bottom the unit. Pull you refrigerator out from the wall and do the same. If it’s within your skill set, turn off the unit, pull the back cover off,  and vacuum out the condenser coils and all the dirt around the fan.
  8. Surface Water Drainage: Culverts, waterways and landscape drainage systems should be cleared of debris and overgrowth that has occurred.100_0206
  9. Electrical Service: Inspect the Entrance, Mast and Weather-head. With tree limbs heavy with leaves, seed pods, fruits and nuts, you may have some limbs that are drooping on your electrical service lines. 
  10. Electrical Service-Smoke Detectors: Clean your smoke detectors of cob webs and change the battery.
  11. Test your security system: Work with monitoring service to validate all the door, window, glass break, and motion sensors operate properly. 

If you are needing some additional information on one of the topics that I have not written about, let me know and I will put it higher on the list of articles to write. Email to HomeownerBOB@gmail.com


Lawn Sprinkler Efficiency Upgrades Part II

April 26, 2009

sprinkler-head3Nearly 60% of residential water consumption can be attributed to landscape watering.

Hopefully you have read my previous posts on “Lawn Sprinkler Efficiency and Chasing Lawn Sprinkler Leaks “. If so, you recognize that a fine tuned system can provide greater efficiency and reduced water usage. However, you may want to go further. Stage III and IV represent some significant decisions regarding  the way you treat your landscape.

Stage III:  Plan to get wet and dirty. This stage will impact the designed water delivery. These changes are a  bit lengthy and involved and may take several weekends to complete the items.

  1. Make a sketch:If you don’t have a drawing of your system, use sprinkler flags to identify each sprinkler head in the zone. You want to identify all heads associated to a zone, one zone at a time. Each existing nozzle/head should include a brand and  a number on the top edge, 10, 12, 15. As well as a pattern identifier 1/4, 1/2 or F.  Sketch out your lawn and zone. Typically, residential irrigation systems are designed based on 30 PSI of water pressure at the head. Go to the manufacturers webpage and look up the GPM usage for each head.   On your sketch identify each head by pattern, radii and GPM. Total the GPM per zone. TIP: Whatever changes are made in the following steps, do not exceed the calculated GPM by more than 10%.  
  2. Correcting design issues: After completing item 1 and 2 you may have noticed some sprinkler heads are not exactly in the right place. This may be based on poor placement, changes or growth in the landscape material.  If relocation is required ensure that you retain adequate head to head coverage with the neighboring sprinkler heads. TIP: Read the nozzle; if the nozzle is stamped with a 10′ on the top, you should have other heads within 100 to110% of the distance of that number  from the head location. So if you decide to move the head, locate the neighboring heads to ensure the relation lawn20edge20pop20up2011stays comparable.
  3. sprinkler-bodies1Replace Sprinkler Body: Similar to #2, but the solution may be to obtain a sprinkler body that allows the nozzle to extend above an obstruction.  If you find pop-ups in flower beds but the spray is obstructed by plant material, changing the head to a riser can provide the necessary reach allowing sufficient coverage. TRICK: Risers (ridged plastic pipe with nozzles) can use the same nozzles as pop-ups but require a transition fitting to convert the threaded pipe to a sprinkler head nozzle. These fittings are brand specific as well.  
  4. Convert from Spray to Stream Nozzles: This is a dramatic change, not to be taken lightly and I would only convert one section at a time to see if you are okay with the results and performance. Even though everything you have done to this point will be beneficial, changing the nozzles will drastically reduce your water usage, but may require longer watering durations. Look for a future write up on Nozzles for a comparison in the water usage. As an alternative to this you may try finding nozzles that are low arc, as lowering the trajectory arc  you are spraying less water high up in the air. Since the  low arc nozzles typically have shorter radius patterns, this may not work, but is worth keeping in mind as you can use nozzles with different arc’s in the same system. Read my article on changing sprinkler nozzles; the payback is not as much as you might want but its worth a look.
  5. Parkway’s: In my neighborhood, I see a tremendous amount of water traveling down the street (everyday) due to this type of runoff. If the area is watered with standard half and quarter circle nozzles, you may consider changing the nozzles to strip spray nozzles. Strip spray nozzles project a rectangular pattern and may help you manage the water usage and overspray. Technically this is still a spray nozzle and it is okay to mix this head with other spray nozzles.  As I mentioned earlier, Irrigators will collect sprinkler heads together to complete a zone water budget, so this zone may include heads in the main body of the lawn and this could complicate your efficiency measures.

Stage IV: More dirt more wet. This stage is very severe, so only consider these steps if you believe you are still not where you want to be with regard to water usage.  Some of these steps are major redesign initiatives and its a lot of work. Hiring someone to do the irrigation work can be expensive as installing new sprinkler systems. You will need to be the judge on Stage IV. I don’t consider these items in order, so weigh your options. 

  1. Change Landscape Material: By changing your plant material to drought tolerant regionally specific plants, you can successfully reduce your watering requirements for your flower beds. Granted if you still have a large amount of turf your water demand is still high. You may consider reducing the percentage of turf. You can replace it with plant material or porous aggregate (gravel, crushed granite, river rock, etc.)
  2. Stop Using The In-ground Lawn Sprinkler: Simple to accomplish and it will dramatically reduce your water usage. Granted, you are back to dragging hoses around the house but point-of-use sprinklers will not use near the water an in-ground system uses.
  3. sprinkler-controllerReplace the Lawn Sprinkler Controller:  Understanding that better water management can further reduce our water usage, typical Sprinkler Controllers (or Timers) provide water on a timed bases. If  the timer is equipped with rain, wind or freeze sensors they will provide a higher degree of water management. Hopefully you already have those add-on devices to your existing controller at this point. However, in Stage IV stepping to a digital grade of water management is required to reduce your water consumption further.  At this point, I have found limited products available directly to the public as most of the “Smart Controller” are defined to be professionally installed.  Many of them require a monthly fee as they are tied to a weather database for regular downloads (I dont like monthly fees). However, I recently found a product called Cyber-Rain. They appear to be headed down the right track, by using your PC and the Internet to upload the most current weather conditions to adjust the water settings accordingly. They use a wireless connection to get to your PC and provide you proprietary software to further manage the water delivery. At $400 it’s a bit steep if you compare it directly to a entry level $60 water timer, however here in Stage IV, we are very serious about water conservation. I have not tested this product but so far I like what I see.
  4. Water Only The Flower Beds.  In my part of the country watering flower beds serves two purposes, 1) to keep the plant material alive and, 2) it reduces opportunities for foundation problems associated with the expansion and contraction of the soil. Assuming your system design has the flower beds in their own zones, it will be simple to just turn off the other zones at the controller.  If you have Bermuda grasses, you can stop watering them  and the grass will go dormant, but don’t try this with St. Augustine or Fescue as this grass will die without water. If the flower beds are combined with the turf sprinklers you may consider #5.
  5. Rezoning  sections: By now you should know where each section is, what it waters and how much water (GPM) per section. Segregate flower beds into their own zones. This may include digging and re-piping some heads from the flower bed zone to another zone.
  6. Convert Flower Beds To  Drip Irrigation: This is all based on the flowerbeds being zoned separately. Since drip system run at lower pressure, you will need to change the zone valve that can support the lower pressure.  Then its a matter of capping the existing sprinkler heads (or turning them off). I have used the (brown tubing) drip-line style, its not quite as efficient as the point-of-use designed to water individual plants as it just has an emitter every 12″ but its a lot less drip-linework and maintenance. If you use this style, the home supply stores can provide you the material required to transition from a sprinkler riser to the new drip lines.
  7. Convert Parkways And Grass Strips to Drip Irrigation: Assuming you can isolate the parkways into their own zones you can use the same drip line mentioned in #4 by burying it about 3-4 inches below the ground spaced at 12″. I did this at my house and have been very pleased with the results. TIP: If you do this, be very careful if do any digging  in the future as this type line is very pliable and can easily be damaged with a shovel.
  8. Add Rainwater Collection: This can be  a major undertaking, I have wanted to do this myself and have researched it for several years but due to certain limitations  on my property its not feasible…yet.  By creating a full house rainwater collection system you could technically rework your system to rain-water-collectionuse nothing but rainwater to irrigate your property.  But here are some things you would need to consider if you are interested. 1)Storing the water, probably in the neighborhood of 1000 to 3000 gallons. 2) Pumps may be required to transfer the water and drive the water through your sprinkler system. 3) Zone valves may need to be changed to accept the water as it will have a bit of dirt in it, 4) Additional filtration may be required to keep the system from prematurely stopping up the standard sprinkler heads. On the other hand, as a simplier approach, using water barrels at the gutters you can easily use this water for hand watering applications.

Lawn Sprinkler Maintenance Can Increase Water Efficiency

April 20, 2009

sprinklers-01In-ground lawn sprinklers are about 50% efficient. Evaporation, poor maintenance and bad design  are the largest impact to that figure.

The spring season has many of us looking to use automatic lawn sprinklers to do our watering.   Hopefully you have read my post on Chasing Lawn Sprinkler Leaks.  This is a good start, but it just barely touches the subject of efficiency. Besides fixing leaks, there are numerous items that can be performed to make your system more efficient without sacrificing performance. Today, the dollar cost of water is still very reasonable, however water conservantion is really about using less and the long-term benefit.  Even though this article will address issues specifically related to systems designed with pop-up type heads, many of the suggestions will work with other types as well.

General Design Considerations:  Understanding how an irrigation system is engineered will help you understand how to make one work more efficiently. If you have a “blueprint” of your system you have a head start, if not, we will perform some hands-on analysis to obtain performance information. 

  • Elements of Design: All systems are designed based on water usage  and gallons of water (GPM) per minutes used by each head. Typically the small pop-up heads use more water per head per square foot watered. Because they apply more water per square foot than other types, they work well for small and medium-sized residential properties. They can also be easily tuned to fit odd spaces with a host of nozzle choices. 
  • Zones or Sections: All sprinkler systems are broken down into zones or sections. The Irrigator calculates the zone size by using available water pressure, pipe size and maximum GPM per zone. Besides these items, zone adjustments may also include special watering needs such as side yards, gardens, flower beds or odd-shaped areas. Since additional zones require more material, labor and money many Irrigators will keep the costs down by limiting the number of zones installed, this is good for him and maybe not so good for you. As you analyze your system and you see one head out all by itself in the middle of another zone, the Irrigator needed a head in that location but did not have enough water budget left in the prevailing zone. This is all very common but can be problematic if you are attempting to manage your water usage at a higher degree than normal homeowners.
  • Sprinkler Heads & Nozzles: There are a half a dozen types of sprinkler heads, but the pop-up style is still the most popular because they can meet varying needs. Pop-ups can be purchased in different levels of spray coverage and are promoted as providing better coverage because they are typically spaced closer together. Typical systems use heads designed with 10′, 12′ and 15′ radius spray patterns as well as strip sprays and bubblers.  Larger properties can use Impulse or Rotary style heads to conserve water as they can be placed very far apart. Because they distribute water in more of a stream vs. spray found with a pop-up style, they do not waste quite as much water per square foot.  Impulse and Rotary heads work well with wide open lots, but don’t work well when there are obstructions such as building structures, trees, and property lines.
  • Mixing Head Types: No matter the sprinkler head style, it is perfectly normal to find a mix of spray pattern nozzles within each zone, and a mixtures of head types in a system,  but NOT a mixture of head type (Pop-up, Rotary, Orbital) in the same zone. Mixing head type can make it difficult to properly manage coverage and watering levels.
  • Optimal Design: The best designed systems account for the water required based on the environment. In other words, shrubs and flowers should be watered at a different rate than turf. Shaded turf may be watered less than turf placed in full sun. Grass type is also influential. Unfortunately, not all sprinkler systems are designed with these considerations as it can be more costly to engineer a system with greater efficiency. TIP: If you don’t currently have a sprinkler system, and are looking to purchase one, beware of the very low bids as some Irrigation Contractors will take short cuts on the items mentioned in an effort to win the business.

EFFICIENCY STRATEGY

Stage I: Gain the most efficiency out of your existing system without impacting the design.  All of Stage I is covered in detail in the “Sprinkler Leak” post. But here are the high points.

  1. Check for leaks in the pressure side of the system. Use your water meter to isolate the leaks in the sprinkler zones.
  2. Check for leaks in each zone. Most leaks are at the heads; repair and replace the heads and risers as necessary. Make sure you use the same style head and similar nozzle sizes as the one you are replacing.  TIP: All the major manufacturers make pop-up heads, its okay to mix brands but if you stick with the same brand, you can always move and change nozzles between existing heads when needed because nozzles are not universal between manufacturers.
  3. Ensure all sprinkler heads are clean and providing the proper water pattern.
  4. Adjust the watering duration and times to match the season.
  5. If your watering durations continue to allow excessive water run off, try changing the watering times to a series of short cycles. For instance, change a single 15 minute cycle  to 3 back-to-back 4 or 5 minute cycles. This can allow the water to saturate before the second and third cycle occurs. Typically, I don’t like the short cycle watering strategy, but if you perform it back-to-back, its okay.
  6. Consider using your system in manual mode only. Watering when only necessary will reduce your water usage substantially. 

lawn-sprinklers3Stage II: Plan to get wet.  This stage requires a bit more effort and the gains achieved may be small, but the intent is to make gradual changes that will increase efficiency without negatively effecting performance.  This stage is intended to optimize the system by fine tuning the existing sprinkler heads. 

  1. Look for excessive water  accumulation. Not all landscapes require the same amount of water. Unfortunately, when irrigation systems are designed, this fact may not be included in the design. Read the system performance by looking for items such as excessive water, green moss or over saturated ground and plants.
  2. Fine tune  individual sprinkler nozzles. Each sprinkler nozzle has a fine tuning screw on the top of the nozzle allowing you to change the water output. However, when you reduce the flow, you reduce the pattern spray coverage. In some cases, you may completely turn the water off at the nozzle. This is sort of a trial and error exercise, so you may need to make the adjustment and keep an eye on the area for proper coverage. Newer style nozzles may include a water saver disk found under the nozzle to equalize pressure and reduce water usage. Adding or removing this disk will also change the amount of water delivered.
  3. Parkway Watering: I mention this because this strip of grass found with many older homes is a large source of water waste with automatic lawn sprinklers. Run the zone that waters this area to determine how much waste is occurring. Adjust it as much as you can. If you still have excessive water run off you may consider adjusting the fine tune screw to the off position and either hand water it or let it go brown and just let the rain keep it green By completing Stage I & II, you should be reducing you water waste. You may be able to reduce your watering duration by the fact that you are wasting less water. Before you move to the next step, let the system run for several weeks/months. Monitor the performance and make further adjustments as necessary to the nozzles and watering duration.

After completing Stage I and II let the system run for a couple of months. Monitor the performance and the water usage, make adjustments as necessary.  However, if you want to go further, I still have Stage III and IV recommendations. Look for my post next week on  “Lawn Sprinkler Efficiency Upgrades Part II“.  

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Searching for Lawn Sprinkler Valves

April 10, 2009

sprinkler-valveFinding the lawn sprinkler valves can be challenging  without the correct tool. Most irrigators have a tool called a cable hound or cable locator. Think of this exercise as an Easter Egg Hunt and the valve is the candy.

Within all Lawn Sprinkler systems they are broken into zones. Each zone has its own electrically controlled valve. TIP: The valves are powered by 24V AC with a very low current flow and is not normally considered hazardous. This valve is activated by the sprinkler timer or controller. Depending on the installer and the application, some installers place them in a cluster where others place them throughout the yard, or a combination of both. In most cases, (not always) the installer will place the valves in an access can or valve boxes. Unfortunately over time,  these cans (or boxes) can easily disappear under the turf. So if you know where they are,  its good to keep the grass cut back from them or have them marked is some way.

Besides providing an isolation point, sprinkler valves can get dirty or become inoperable. For the most part, the valve can be serviced with replacement parts assuming you know the exact brand and model of the valve.  Read this link on sprinkler valve repair. If the valve is still leaking after a thorough cleaning and inspection, acquire a repair kit and replace all the parts. Rarely would you need to actually remove the valve body from the system unless it became frozen during the winter and the body was cracked. If it was cracked, you should have noticed the valve leaking before you started the dis-assembly process. TIP: Avoiding the cracked valve body is one of the reasons it is recommend to turn off and drain the sprinkler system in the off season.

Finding the valves can be challenging  without the correct tool. Most irrigators have a tool called a cable hound or cable locator. These test sets are about $400-500, so purchasing one is probably out of the question.100_0203 It may be possible to find a rental, but most people that require them usually own them.

Finding zone valves:

  • Cable locator: Professionals use a cable locator to find the valves by tracing the path of the electrical wires that feed each valve. If you have one of these tools or have access to one, this is the simplest and quickest method.  The tone typically get loud when you reach the valve. As an alternative to a Cable Hound, I have tried a low cost test set from Harbor Freight but cannot recommend it as it did not work as I had hoped. It was not really intended for this type of use, but it was worth a shot for the price.  As an alternative, you can hire an irrigator to make the repair and ask him to locate  all the other valves as well. They may not even charge you to find the other valves since they are charging you for the visit and repair. 

So if you are going to try to locate them on your own without a locator, try the following methods:

  1. Design drawing. Hopefully you were left with a drawing from the installer or the previous owner of the property. If  you have any record of who 100_0409installed the system, they may still have one on file.   Find the valves identified on the drawing and use a long screw driver or probe and a shovel to poke around in the dirt. When you hit a valve box it will have a hollow sound to it. They will probably not be in the exact location but hopefully within about 5 feet from where the drawing indicates it.
  2. Origin of Water: The system should have a back flow preventer in a large rectangle box, usually near the water meter.  The sprinkler valve(s) will be located somewhere between the back flow preventer first sprinkler head. Look near the first head of each zone.
  3. Valve Chatter: Assuming you can still turn the system on and off, you can have a friend turn the system on/off multiple time. The valve will make a slapping or hammering noise that may be loud enough to pin point the valve location. 
  4. If you have gone through this without sucess, you may have to call the Irrigator anyway, hopefully using some or all of these methods, you were able to find the valves.100_0411