Rooftop Garden/Greenhouse/Water Collection System
Our school was built in 2013 and is LEED-certified at the Silver level. That said, for a building that is supposed to showcase environmental responsibility, there continues to be a shocking lack of “green” both in and outside of our school. Last year, with the help of LSF EcoLeague funding, we began transforming our empty rooftop terrace into a green space. There were some challenges to be sure but we succeeded in engaging our students in garden design, creation and maintenance and showed them how an empty rooftop can be put to better use. In the end, we built 7 large planting boxes and three large pots and we harvested and sold approximately $60 worth of organic vegetables back to our school community as well as supplied herbs to our school cooking class.
As mentioned, however, there were challenges. Difficulty in maintaining a regular watering schedule (in particular, over the summer), mixed with the excessive amount of wind and heat that the rooftop receives because of its direct exposure to the sun and sky meant that we lost a significant portion of our crops to drought and extreme wind.
We believe that a sustainable Canada is one in which urban agriculture plays a major role and we aim to use this space to demonstrate the limitless potential for urban spaces to contribute positively to our food system.
We rebuilt the planters to increase their depth and built a greenhouse on the terrace by building a structure that encloses the planters with slanted clear plastic roofing. This will achieve a number of goals:
1) Turning it into a greenhouse will more evenly distribute the sunlight and extend our growing season.
2) The enclosure will act as a wind barrier, protecting the crops from the high winds seen on the terrace.
3) The slanted roof will feed water into a rain barrel which will be hooked into the new planters to provide a continuous source of water.
To achieve that last point, we buried soaker hose hooked up to a water barrel which is connected by an eavestrough to the roof of the greenhouse to deliver water as needed and reduce the impact of an absence of regular watering during the summer months. Having deeper planter boxes will also help us produce heartier crops – many of our crops didn’t have sufficient soil depth in our initial planter designs to grow.
Reflection & Celebration
This project was not without challenges. The greenhouse/water recuperation structure had to be rebuilt 4 times as the wind of the roof of the school can get extremely strong and the structure was not withstanding it. Each and every time, the students identified the weak points and completed a redesign to strengthen it. The final structure today is extremely solid, though significantly smaller than what was originally planned. The water recuperation system also had to be redesigned as the original design was unable to handle the capacity of a heavy rainfall.
We held an end of the year celebration with all the parents of the students of our Environmental Leadership program where we conducted a tour of the various action projects that the students had completed, including the greenhouse. We posted pictures on Twitter to celebrate its completion.
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