In Cambria and similar communities, the deepening impact of the drought recalls the words of Samuel Johnson: “When a man knows he is to be hanged in a fortnight, it concentrates his mind wonderfully.”
The first response to drought is to try to find ways to increase water availability. In recent discussions this has taken the form of proposals for deeper wells, use of brackish water, desalination of sea water, etc. This approach, although the most obvious, is not necessarily the only one or the most practical.
There is another approach that should be considered for non-agricultural needs in communities, which those of us in the appropriate technology sector have been working on that can be less expensive and easier to achieve. It combines both production and use of resources that are right under our noses but seldom recognized. In addition, this approach is available on a scale we as individuals can utilize directly without large industrial and bureaucratic processes that can add stress to already fragile environments.
The appropriate technology organization SLOCOAT, a coalition of SLO Green Build, SLO Permaculture Guild, the Sierra Club and the Surf Rider Foundation, has been developing these techniques for the past eight years and has developed three publications in conjunction with local governments to illustrate how to do this.
These are: “SLO County Guide to the Use of Graywater,“ “Rainwater Management for Low Impact Development“ and “A Guide to Rain Water Harvesting.“
This appropriate technology approach, which combines added production and more efficient use at the scale of our individual buildings, has the potential to greatly reduce our vulnerability to drought conditions likely to become more common with climate change.
Let’s take rainwater harvesting, for example. If you look at the average rainfall amounts at various places in our county (Page 3 of the Rainwater Harvesting Guide) and contemplate the average roof area of buildings, you will appreciate the significant quantity of water we are talking about with just this one at approach. With a large enough cistern and careful design, it’s clear that many buildings in our county could be self-sufficient in regard to water production and use. A residence in North County built with such a system at the beginning of the current severe drought had already collected 5,000 gallons, much of it from frost that formed on the metal roof of the building at night, even before the recent storms. With the rainfall, all five tanks are now full, for a total supply of 25,000 gallons.
SLO Green Build and local consultants from SLOCOAT are presently looking at what to do with the septic tanks in Los Osos that will be decommissioned once the sewer is operational. We have found that using them in conjunction with rainwater harvesting, collection and treat ment of gray water and low impact development produces significant potential for replacing much water that is pumped from Los Osos’ stressed aquifers. Rainwater harvesting only occurs in the winter, but gray water is available yearround. We are also looking at the potential for fog collection in the summer as is done in some similar coastal climates.
Much work remains to be done using appropriate technology for water production and use but in eight years we have discovered enough to see the opportunity this drought gives to successfully apply this approach.
Necessity is the mother of invention, but in this case, what we require is already at hand, needing only to be implemented.
Kenneth Haggard is cofounder, with Mikel Roberson, of the SLO Coalition of Appropriate Technology (SLOCOAT) and principal architect with San Luis Sustainability Group, a 30-year-old firm specializing in green architecture, sustainable planning and appropriate technology. He is author of several books on sustainability and design and professor emeritus, School of Architecture, Cal Poly. Lana Adams is past executive director of SLO Green Build and a consultant in sustainable building practices.
FOR MORE INFORMATION
Publications on harvesting rainwater, use of gray water and rainwater management can be downloaded free from SLO Greenbuild’s website, http://slogreenbuild.org.