Posts Tagged ‘reducing demand’
So we left off talking about one of the 8 LEED scoring categories. Water Efficiency. Last week I talked about one of the three sub-categories of Water Efficiency; water reuse.
This week I’ll talk about one of the other two sub-categories; outdoor water use.
Outdoor water use has to do with the irrigation system for the landscaping. You’d think that the landscape design and the kind of plants etc would dictate how much water gets used and to a certain extent it does. But in reality it’s possible to have a completely inefficient irrigation system watering an expertly designed LEED certified landscape plan. That’s why landscape is part of another LEED category called “Sustainable Site”. To earn LEED points for outdoor water use, Irrigation systems must be designed and installed to minimize the amount of water needed to maintain the landscape. Although a lot of this is kind of obvious, you’d be amazed at how much is overlooked and ignored in most of the irrigation systems installed.
There are two ways the maximum amount of points can be earned for outdoor water use. One is install a high-efficiency irrigation system and have a third party verify its efficiency. The other is to use a formula that calculates the amount of water needed to irrigate a specified landscape area that takes into account species, microclimate factors and irrigation equipment and then reduce that amount by 45%. If that sounds complicated and subject to serious interpretation issues, I agree. The first way is much easier to comprehend and implement. Here you get points for adopting at least three of 7 “strategies” that create an efficient irrigation system. Obviously it would be most efficient to adopt all 7 but LEED at this time gives max points if you adopt three.
Design a system with head to head coverage is one. Doing this keeps the water coming out of the heads from overlapping each other causing some areas to be watered more heavily than others. A second way is to use drip irrigation on at least 50% of the landscape beds. This puts more water in the ground and less in the air through evaporation. A third is to create separate zones based on the bedding type. More porous bedding types obviously absorb water quicker and can stand longer watering times while non-porous beds will create runoff in the same time frame. Installing a timer is a fourth way. This allows the landscape zones to be watered at the best time of day to avoid evaporative effects and to only water for a specified time related to the needs of each zone. Fifth is to install pressure regulating devices to maintain proper pressure and avoid misting. Misting water never hits the ground and ends up as humidity in the air. Sixth is to use high efficiency nozzles that control distribution uniformity so areas within the zone receive the same amount of water. And seventh is to install a moisture sensor controller that shuts the system down in case of rain. How stupid is it when you see someone’s sprinklers on while its raining.
As I said its best to use all 7 seven strategies but for LEED purposes you max out in terms of points at three. I think over time in locales that have water issues, all these strategies will be law instead of optional, and in reality they should be. As I said before most of the growth in this country is occurring in areas with water issues and learning how not to “waste” water now, makes it easier in the future.
Next time we’ll talk about indoor water use.
So last time we talked a little about water efficiency. I talked about how water is an interesting natural resource because we definitely need to be efficient in its use, but not because of its scarcity. In fact water is basically an unlimited resource. We need to be efficient in its use because it’s a pain in the ass and costly to procure, treat and distribute. Especially if you live in an area where it doesn’t naturally exist…..like most of the southwestern portion of the United States. Of course that’s ironic because MOST of the growth in this country in the last 50 years has occurred in the southwest portion of the United States.
Remember I also said last time that growth can be severely limited by access to water. As a region tries to grow, if it can’t get water, it won’t grow for long. As the costs of getting MORE water to an area increase, it will eventually become a situation where those costs will exceed the ability of that region to grow. If the costs of getting MORE water are prohibitive, then the only way to grow is to use the water that you ARE getting more efficiently.
LEED awards points in their certification process for building new homes and neighborhoods that use water more efficiently. There are three areas points can be earned.
First is the reuse of water. And there’s three ways points can be earned there. First we can capture and reuse rainwater. Obviously it can’t be used for everything as it isn’t treated for drinking or bathing purposes, but it can certainly be harvested and used for landscaping. Of course it’s a little expensive and impractical to try and harvest rain in an area that has little or no rainfall so we haven’t looked at this option very seriously.
Second is the use of “gray water”. Gray water is untreated household wastewater that has not come into contact with toilet waste, kitchen sinks or dishwashers. It includes used water from bathtubs, showers, bath sinks, and clothes washers. Toilet waste and used water from kitchen sinks and dishwashers is called black water. It cannot be reused. Gray water absolutely can be reused for landscaping purposes. A sewer system must be devised that separates black and gray water and diverts them to different areas. This is where the cost comes in. In most communities ALL wastewater goes into the same sewer system and ends up in city treatment facilities. LEED will award points for a project that devises a system to separate and capture gray water so it can be reused.
Third is utilizing a Municipal Gray Water system. Some forward thinking cities have their own systems in place that separate gray and black water. Building a project that hooks into that system gets LEED points as it helps use water more efficiently.
The other two areas LEED awards points for has to do with outdoor and indoor use. I’ll address them next time
So last time we defined “green” as any effort or strategy undertaken to reduce the demand of natural resources. Any effort. Any strategy. Any natural resource. It’s that simple. You can put the label of “green” on any effort or strategy that achieves the goal of reducing demand on any natural resource. I repeated it on purpose to emphasize that when you hear the word “green”, you should ask yourself; how does this reduce the demand on a natural resource? If it doesn’t, it isn’t “green”.
Of course the interesting fact about this “green” movement is that even if the entire world took a “green” stance tomorrow all it would actually do is stall the issue of natural resource depletion. Think about it. Its math. Demand obviously grows with population. To illustrate, let’s use simple numbers, say that today one hundred people use one hundred trees, or one tree per person per year. If everyone adopts “green” behaviors and cuts the average use to a half tree per year, yet the population doubles to two hundred people…..well then one hundred trees still lose their lives every year. Even though we can say we’re all “green”, we’re still headed for natural resource depletion; in this case trees. We just delayed the process because I’m pretty sure we’ll keep adding to population.
Seems like a good time to introduce the term “sustainable”.
Actually before I do that, let’s talk about natural resources. I know we all remember from grade school geology, biology, chemistry and geography what a natural resource is (unless you slept through those classes), but what do we mean by natural resource in this context? Well, virtually all the “stuff” in our lives started as a natural resource. Yes there are some man-made chemicals that have enhanced our lives, but for the most part everything we see, smell, taste, hear and touch started as a natural resource. Trees, water, coal, oil, gold, copper, etc are examples of natural resources. As humans, we’ve used natural resources on their own, and in combinations, to create virtually everything in our lives. For thousands of years, the ratio of humans to natural resources was so low, no one really cared about using as many natural resources as they desired because it was incomprehensible that a planet as large as ours could actually run out of what appeared to be an endless supply of natural resources.
Of course it was probably as equally incomprehensible to those early humans that eventually there would be six billion of us. Guess what? There is. Not only that, but it only took 34 years to go from three billion to six….and best guess is about another 25 years to double again to 12 billion. That ratio of humans to natural resources I spoke of, has done a massive flip flop to the point where I don’t think any one of the six billion of us is dumb enough to think that pace can continue unabated. In other words we can’t “sustain” the level of natural resource depletion that this level of population increase will demand. Or can we?
Which takes me back to the word “sustainable” But I’ll save that for next time.
So what does “Green” mean? I find it interesting that it seems to be human nature to define something, and then broaden the definition so much that, over time, no one really knows the true definition. Or they end up with their own definition. Take the word “celebrity”. It used to be easy to define “celebrity”. One had to be talented and famous. Today you don’t have to be either. Pretty much any goofball with a gimmick or the right connections can be labeled a “celebrity”. Over time the definition has broadened so much it’s become essentially subjective.
“Green” suffers from the same problem. So to actually blog about “green” building, I feel I need to define the term as City Ventures sees it, so readers won’t apply their own definition after years of having the definition broadened so much that the term is meaningless. I saw an ad for a “green” diaper the other day and one for a “green” detergent. How can a diaper be “green”? For some reason it doesn’t seem plausible that a diaper can be “green”, a detergent can be “green”, and a house can be “green”, and it certainly doesn’t seem plausible that they all three mean the same thing when they label themselves as “green”.
So let’s define “green”.
As an Economics Major 100 years ago, I learned about the term scarcity. The whole basis behind Economic theory is that ALL resources on Earth are scarce and the study of Economics is how those resources get allocated amongst people. That’s called Economic behavior. Natural resources are no different than manufactured resources or service resources. They are scarce, meaning there is not an unlimited supply of them available. The demand for natural resources relative to the supply of them results in their price. As global demand for natural resources increases with population growth and supply decreases with resource depletion, the price goes up. It’s bad enough that the price goes up but the bigger issue is that eventually the supply runs out. In that case there is no price that creates equilibrium between supply and demand. The resource is gone….. and once it’s gone, it’s gone.
It doesn’t take much of an education to figure out that at the present rate of natural resource use, combined with the assumed rate of natural resource use as the worlds developed population dramatically increases over the next few decades, means demand of natural resources will eventually ELIMINATE the supply. Sounds a little extreme. But is it? Do we really think we can continue to use natural resources forever? It’s not logical.
“Green” is defined as any effort or any strategy undertaken to reduce the DEMAND of natural resources. Any effort. Any strategy. Any natural resource.
I need to expand on this subject further in the next blog as we’ll get into terms like sustainable and LEED certification. Plus I need to define “Green Building” . But that’s it for now.