Subsurface Drip Irrigation Guide - Page 4

Before we begin this section, we need to agree that plants have a requirement for a certain amount of water, and that this requirement will vary by plant type, region and time of year. The irrigation system that can deliver the proper amount of water to meet those needs without waste due to runoff, overspray, evaporation, over-watering to ensure you don't get donuts, etc., will be the most efficient. By now you have seen that dripperline and drip irrigation do just that, and by being the most efficient method, and drip and dripperlines, they save water that otherwise would not have been used by the landscape.

"Irrigation Application Rate Efficiency" is one of those topics where good contractors are often separated from other contractors. It refers to what percentage of water being applied actually gets into the active root zone. What that percentage is has been a hotly-debated topic.

Dripperline uses less water (because it reduces waste) and grows healthier plants than sprinklers. If it didn't, most of the vineyards in California and around the world would use sprinklers, and most of the greenhouses would just use sprinklers. But they don't, because they know they can use less water (higher application rate efficiency) with drip and dripperline than with sprinklers. The amount varies from area to area. On a hot, windy day in southern Arizona, maybe 30% of the water from a sprinkler gets usably into the root zone. In New England, maybe it's 70%. Where does the other water go? Everywhere but where it should.

In short, sprinklers are inefficient. They use too much water and waste much of it.

Water has always been critical to life, but it is only now beginning to get the national attention it deserves. In areas like Marin County, restrictions have been in effect since the late 1970's regarding the amount of turf allowed. In areas like Denver, Colorado, entire bans have been placed on sprinkler systems because of the drain they place on available water. In several southwest U.S. communities, sprinkler irrigation has been completely banned for narrow areas.

Figure 25 - How easy is it to ban watering? This is easy.

Here are some realities of water in the United States: With increasing populations come increasing strains on the water delivery networks Almost half of the potable water delivered is used for outdoor water (in some areas in the southwest it approaches 80%) Municipalities cannot afford to build new infrastructure to support the wasteful use of water Much of what can be done in the home to save water (low flush toilets, low flow shower heads, etc.), has already been done. Yet these have a more limited impact on water usage than conserving irrigation water.

• With increasing populations come increasing strains on the water delivery networks
• Almost half of the potable water delivered is used for outdoor water (in some areas in the southwest it approaches 80%)
• Municipalities cannot afford to build new infrastructure to support the wasteful use of water
• Much of what can be done in the home to save water (low flush toilets, low flow shower heads, etc.), has already been done. Yet these have a more limited impact on water usage than conserving irrigation water.
• Onto the blades of grass or petals and leaves, there to be evaporated
• Down the sidewalk
• Down the driveway

That leaves outdoor water use, and water districts are taking an increasingly aggressive position on its use. Their position is clear and simply put. Just because you buy the water doesn't give you the right to waste it.

Having said that, water purveyors are also sensitive to the political climate and they are not about to demand that everyone forfeit their lawns and gardens "for the cause." They are prepared however, to issue restrictions, and in some cases outright bans if needed. They also recognize the important role a healthy landscape plays in housing values, quality of life as well as the vital role that landscape plays in cleaning the air of pollutants, its cooling effects, and its ability to create oxygen.

So here we are, wrapping back around to the issue of application rate efficiency and the proof statements that drip and dripperline irrigation saves water yet deliver as good or better a result in lawns or gardens. We find it in programs written by the U.S. Green Building Council (www.usgbc.org) which developed a comprehensive, voluntary, consensus-based national standard for developing high-performance, sustainable buildings. In it, they recognize the water saving ability of low volume by assigning an efficiency standard to it that is far higher than for sprinklers.

It is found in municipalities that allow drip and dripperline systems to be used without interference when restrictions or bans are being placed on overhead sprinkler systems.

We say that our products will typically grow a plant to maturity in about half of the time of a sprinkler system, that we will use about half the water, and that when restrictions are being placed on sprinkler systems, low volume irrigation will not typically be part of the restriction. As you can now see, we say it from a strong position.

There is an excellent story that Herb Kelleher, the genius behind Southwest Airlines tells. He was approached by a Southwest Airlines board member and asked if they should raise their $19 fare because a competing airline on the same route was charging $59. Mr. Kelleher pointed out that Southwest wasn't competing with other airlines. They were competing with ground transportation.

Herein rests the heart of the matter with low volume products:

• They grow and maintain turf and plant materials better than sprinklers
• They use far less water
• They require less maintenance
• They typically enjoy an exemption when other forms of irrigation are restricted or banned

Conclusion: A Netafim dripperline system is less expensive over its lifetime. Not just for the end user, but for the community and the environment as well. To compare dripperline irrigation systems to sprinkler systems is like comparing airplanes to buses.

In the 1970's it was common to see manufacturers run ads touting how the "grass is always greener" with their brand of products. Those ads were based on the assumption that people wanted green grass. It seemed logical, but it was a bit over-simplified.

As companies began doing more research, they found that people wanted green grass but they also wanted more free time. They were willing to buy an irrigation system if it gave them the free time they wanted, but it had to be within reason. The contractor largely determined the system that was installed because the buyer was basing most of his decision on which contractor he wanted. The type and brand of products that would be installed was left primarily to the contractor. Studies at the time concluded that over 70% of potential irrigation system purchasers could not even name one brand of underground irrigation equipment!

Where are we today? The dynamics of the buyer have changed. They grasp resource conservation, and it has become something they (we) all deal with, and in many cases embrace. Whether it's the recycling bin, taking cans and bottles back to the grocery store, or considering a hybrid car, the conservation theme has permeated the minds of the consumer. The use of rain shut-off devices is one such example in the irrigation industry today. Something else has happened as well, the internet.

It is common today for a potential buyer to be much more active in the product selection process than he was in the 70's, 80's and early 90's. He studies which furnace, dishwasher, TV, automobile, and irrigation system is best suited to his needs.

This carries over and beyond residential irrigation and includes commercial and institutional as well. Today's buyer has a better idea of what is available than ever before. As well, he is prepared to listen to a water-conserving proposition from the contractor.

Conclusion/Reality: It's not a day that is coming. It is a day that is here, and the contractor best able to fulfill the needs of today's client, not yesterday's client, is the contractor who won't have to try to understand why business has dropped off.

Subsurface Drip Irrigation Guide - Page 4