The Hole We Dug
As you may or may not have noticed, some dirt has been moved at the bottom of Fairview. A shallow hole, encircled by orange cones and poorly applied caution tape, now occupies much of the space adjacent the teacher parking lot, colloquially referred to as “cancer hill.” A little further down the hillside, an enormous heap of dirt resides. This daunting dirt mound-- soon to be removed by BVSD’s wonderfully cooperative maintenance personnel-- offers visual testament to the amount of Colorado soil we displaced last weekend… by hand. Indeed, over thirty kids showed up March 15-16 to help construct the beautiful, new, currently-offline-but-soon-to-be-functional bioretention cell, that now occupies that space. Many were members of Net Zero, Fairview’s environmental club, and many more were National Honor Society volunteers. On Saturday, these heroic students wielded shovels, wheelbarrows, pickaxes, and the occasional donut, and dug for a good five hours. On Sunday, we finished digging, then filled the hole with a layer of gravel followed by a layer of engineered soil mix. Beneath these materials lies a 10-ft perforated pipe pointing towards the french drain that protrudes outwards from the cell, towards the bushes. What is this thing we built? What will it do? I’m glad you asked. This is essentially an engineered garden, called a bioretention cell, which offers a sustainable water management solution. It’s a Net Zero project that was initiated and spearheaded by Fairview senior Katie Li. She has been working extremely hard all year to make it happen, and others have offered invaluable assistance. The project is basically about harnessing the power of a natural system to mitigate the damage of a human system. Earlier this year, local engineer Dr. Scott Struck visited Net Zero to explain the value of this project. He explained that in nature precipitation is absorbed into the soil where it gradually makes its way towards lakes and rivers. The concrete that now lines our cities, however, isn’t permeable, which creates the need to engineer water and drainage management systems.
The conventional solution is to build concrete channels that shuttle water from streets into rivers as quickly as possible. But this creates some problems. First, water flows into rivers too quickly, creating serious erosion. But perhaps more worryingly, the runoff that arrives in rivers is dirty, having bypassed the essential filtration offered by plants and microbes in the soil. A bioretention cell is a more modern form of water management. It’s a garden, full of specially selected plants and healthy soil, engineered to accept a certain amount of runoff. The cell slows the water down and filters it, then sends it on its way. Nice, right?! The location we picked is great because it will capture runoff from the parking lot, which is likely to contain hydrocarbons from cars. The system is currently “offline,” because the curb is still intact, meaning only minimal runoff from the sidewalk above will enter the cell. Also, there are no plants currently planted. In the nearby future we’ll cut out a segment of the curb, allowing all the intended runoff to enter the cell (which will be full of plants) and the whole thing will be thoroughly groovy. To the interested reader here are a few more details on the process. First, Katie and Fairview senior Rosa Lawrence applied for a grant that YOAB graciously granted. Then, we got permission to carry out the project, and BVSD Director of Maintenance Mike Cuskelly helped us pick a spot. Groups of Net Zero students calculated the area of runoff that would enter the cell and designed the system accordingly. We used the resources of Urban Flood Drainage and Control District heavily. We used our grant money to buy plants from The Flower Bin and soil and gravel from Pioneer Sands. We got pipe and other materials from Home Depot. Both Pioneer Sands and Home Depot were kind enough to discount items so we could stay within our budget. Throughout the process, Dr. Scott Struck of Geosyntec Consultants has been unbelievably helpful. He not only helped us design the cell, but in a totally unexpected a deeply appreciated gesture, he even helped build it. This guy holds a pHD and designs these things for a living, and he picked up a shovel to dig with us all weekend! He also brought a former student and a current civil engineer from CSU, Kristen Wiles.
We are deeply grateful to everyone that helped make this project a reality.
By the end of the year we’ll get the system up and running, and for many years to come we hope it will offer a valuable contribution to Fairview, as an aesthetically pleasing site for sustainable water management. We also hope science classes will be able to incorporate the project into their curriculums, as the cell offers a hands-on opportunity to study filtration, water quality, and plant processes from a chemical, biological, or even physical perspective. If you want to help bring the cell to life and maintain it in coming years, please get in touch with Katie or I, through the email firstname.lastname@example.org.
So there you have it. That’s what you need to know about the hole we dug.