Water Energy Nexus
Water, water everywhere, but what is right for me? With water we do have lots of choices, and not all are created equal. You are probably wondering what I am talking about. What choices, what water?
Of course there is city water that most of us utilize abundantly. But we also have rainwater, greywater, and blackwater. All of these are potential sources of water that could be used to drive our netwater use to zero or better, and help us to become a net producer of water.
Each one of these waters has different characteristics that makes it well suited for a primary, secondary, and tertiary use. Each type has different up-front costs and varies on the impact to net water use. For example, city water has chlorine added to help keep it disinfected en route to our homes from the distribution plant. This same chemical may create healthy water for us, but over the long term is not healthy for plants. It creates salt build-up in the soil that rainwater and fertilizers help offset. City water is a good primary source of potable water, but should be secondary or tertiary when it comes to landscape use. Of course, the advantage of citywater is that it is plumbed to almost every house.
Examining the sources of water without considering costs would result in a much different water use pattern. For example, if all homes were plumbed for water storage and had water filtration systems, we would use the best water for the right use to minimize or eliminate our “water footprint.” Looking at our water use from this perspective than our water use pattern might look something like this:
• City waterwould be used only for drinking water
• Rainwaterwould be used to wash clothes and flush toilets
• Greywater and blackwater would be used for landscaping
If implemented in this fashion, each resident’s water footprint would drop significantly— to just 15 gallons per day. Compare this to our citywide average of 90 gallons!
Besides the obvious benefits of saving water and extending our water supplies well into the 22nd century, our plants and soils would be healthier, producing more fruit, vegetables, flowers, and shade at a much lower water cost than today. We have vast amounts of wasted water. We must view it as precious and irreplaceable. With thismindset again we will begin to change our behavior and secure our water security for decades to come.
Doug Pushard, founder of the website www.HarvestH2o.com, has designed and installed residential rainwater systems for over a decade. He is a member of the Santa FeWater Conservation Committee, a lifetime member of the American Rainwater Catchment Systems Association, and an EPAWaterSense Partner. He can be reached at doug@HarvestH2o.com.