The reason for the Artic Sea Ice Death Spiral is apparent when you look at the continuing upwards march of atmospheric carbon dioxide levels, as reported in early May by Andrew Revkin.
Truly depressing news, eh? Is anybody listening? Are we all doomed? It’s time for some good news, something that gives a little bit of hope.
Apparently, young people don’t drive as much, anymore; the bloom is off American’s love affair with cars and this can only be a good thing. Researchers believe this is a stable, long-term reduction in miles driven that started in 2005, before the beginning of the Great Recession. People age 16 – 34 have reduced average miles driven by 23% from the 2005 peak. Even higher income young people are driving less, evidence that this is a behavioral choice unrelated to the cost of gas.
We can only hope for more good news as the world changes.
The journal Nature published a commentary on March 21 that argues for a new way of thinking about sustainability, with the traditional three pillars of economy, environment, and society instead conceptualized as a nested set, as in the illustration below.
“As the global population increases towards nine billion people sustainable development should be seen as an economy serving society within Earth’s life support system, not as three pillars,” says co-author Dr. Priya Shyamsundar from the South Asian Network for Development and Environmental Economics, Nepal.
Is the three pillars of sustainability model outdated and no longer serving us? We find ourselves often struggling to fully integrate our own thinking – humans are categorizers, a trait that has served us well throughout history up until recent times. But now it is obvious that even our conception of sustainability has been flawed and does not reflect reality.
We find ourselves still struggling to convince people that the economy and environment are not in conflict and that the economy should be designed for human well-being. Perhaps with this new concept, thinking will begin to shift.
“Ultimately, the choice of goals is a political decision. But science can inform what combination of goals can achieve a sustainable future. And science can identify measurable targets and indicators,” said Dr Stafford Smith.
At the Council for Watershed Health, we believe that identifying and tracking measurable goals is vital to achieving that sustainable future. These new Sustainable Development Goals and the conceptual model should be adopted to advance “The Future We Want.”
Now that the infiltration trench and bio-swale have been constructed, it is time to lay the sidewalk, which goes on top of the infiltration trench. How’s that, you say? Putting a sidewalk on top of the place where water is supposed to soak in? For the Paseo, we installed pervious concrete but even if we had used regular cement, it still would have worked as the system is designed to receive water from the bio-swale underground.
The Pervious Concrete Pathway winds its way from one end of the Paseo to the other, providing a pleasant and safe path. Pervious concrete has ‘voids’ or gaps that are created when the fines are removed from mix thereby allowing water to flow through the concrete. Water falling on or over the pervious concrete will flows through these spaces to the infiltration trench below it. To begin construction of the Pervious Concrete Pathway, a course of gravel was spread out over the infiltration trench and areas of the exposed impervious liner.
Unlike Portland cement concrete, pervious concrete sets up quickly. Many hands were needed to pour, spread, smooth, and score the concrete. The choreography of material and work was impressive that day and kudos to Rudy and his crew at J&M Contractors for a pathway many will enjoy.
To aide in the curing process and protect from errant soil or debris, the completed pathway was covered with plastic sheeting. Below you see the completed pervious pathway along with one of the landscape boulders.
Next up is construction of the Forebay, an important element of the design to protect the bio-swale from erosion and clogged soil.
In Part 1, we showed the initial steps in constructing the infiltration and bio-swale. Part 2 illustrates the complex choreography of marrying the infiltration trench and the bio-swale.
The majority of water entering the Paseo will be directed to the bio-swale, which will filter and allow water to infiltrate the soil and migrate to the infiltration trench. To maintain the function of the infiltration trench, we need to prevent soil from the bio-swale from filling in the voids and gaps. A geotextile – a tightly woven material – both helps prevent soil from moving into the infiltration trench and allow water to move into the trench.
The crew placed a layer of geotextile on top of the base layer of gravel and marked it to indicate where the edges of the infiltration trench and the bio-swale met. One side will have soil and the other will have gravel.
The challenge when backfilling the trench with gravel and the swale with soil is to maintain the vertical edge of the geotextile. To achieve the vertical profile of the geotextile, the crew placed plywood on edge to create a vertical guide. On one side of the plywood, a course of bio-retention soil was placed, then the geotextile that lay in place on the trench was “flipped over” the plywood guide to ‘cover’ the bio-soil layer and a course of gravel was spread out, then the geotextile was ‘flipped over’ the course of gravel and a layer of bio-soil spread out.
This sequence continued until the heights of the bio-soil and the gravel met the desired elevation points. The crew started in the center of the Paseo and worked out toward either ends of the Paseo. Kudos to the Paseo’s Field Superintendent Jose Esquivel, American Landscape, who masterfully choreographed the complicated logistics required for the delivery of gravel and soil and the work of spreading the materials.
The Elmer Paseo is all but complete – we still have some finishing touches to add so it won’t be officially open until the new year. For all of you stormwater geeks, following is a photo essay showing how to create a clean water alley.
The Infiltration Trench and the Bio-swale. These two main features needed to be constructed simultaneously and included some challenging logistics. Down the center of the Paseo, the construction crew excavated a 4 foot deep trench which exposed the sandy native soil that is ideal for infiltrating water. Next they had to apply a layer of clean sand to help maintain consistent infiltration the entire length of the trench.
To protect the adjacent properties from water migrating toward their properties, workers installed an impervious liner along both sides of the existing wall, creating a funnel of sorts to direct water toward the open bottom trench.
Next, workers backfilled the 4’ deep trench with rough angular gravel, which creates voids or gaps between the rocks which allow water to collect and flow through the gravel to the bottom of the trench where it will infiltrate to the native soil. Smooth rocks will ‘lock’ together, preventing the formation of voids and gaps for water to collect.
The vision of the Los Angeles & San Gabriel Rivers Watershed Council says that by 2025 “the Los Angeles region has become a model of sustainable urban watershed management.” This vision is the conclusion of a long list of criteria of sustainability that were adopted in 1996 and reaffirmed in 2008 by the Board of Directors of the Watershed Council. You can read the complete vision statement on the Watershed Council’s website. It is a very ambitious vision.
Let’s set aside for a moment the deadline of 2025. Does sustainability even make sense for an urban region like Los Angeles? Are the criteria for sustainability achievable? And there is that deadline. I’m sure in 1996 it seemed comfortably far away, but the future is rushing towards us. No one knows what the world will be like in 2025, but we can imagine. I’ve read plenty of dystopias, thank you, and I would prefer to work towards utopia, even if I believe it to be unrealistic. I grew up watching Star Trek, afterall.
This blog, then, is a place to explore the idea of sustainability in an urban city – who, what, where, when, and especially how.