Urban Water Harvesting System

This is a reflection on Brad Lancaster Urban Water Harvesting System talk.

Brad starts this monologue with a key question “What is the story of this place?”. Navigating the spiral of thoughts this question arises, I can appreciate its depthness. With the rise of the locavore movement, this question gets more validity as human populations start to realize the impact, positive or negative, we have on the natural landscape.

Water is a precious resource that for years has been misused, exploited and polluted with little understanding of its interconnectedness with the natural world in urban areas. By placing concrete structures on top of soil we have essentially broken the natural connection between rainwater and soil. We then went ahead and developed water applications such as toilet flushing, washing machines and showering as modern uses of pristine water supplies. Increasing human populations coupled with mismanagement of water applications has led to a dehydrated urban landscape. Furthermore, our cities have evolved into landscapes dissected by impervious surfaces such as concrete pavement for pedestrian sidewalks and gravel for roads – leading to an increase in flood events causing extensive damage to homes, families and ecosystems. Even though we have brought these issues into ourselves, there are still practical solutions that can be regenerative rather than degenerative and can “reconnect us with where things go”. Solutions that instead of following a path to scarcity guide us into a path to abundance. 

In hot climate areas, surface water is mainly lost to evaporation which leads to more water vapor into the air hence higher temperatures, and the feedback loop continues. To solve this problem, guiding water under the surface of the earth can help us avoid water evaporation and increase the water capacity onsite. For example, the water harvested from your roof can be guided to a fruit tree nearby your household to minimize systemic water consumption and increase fruit production. A great solution will be to have a 2% soil slope from the spout outlet to the tree so that water that infiltrates the surface and goes below the surface (or subsurface), makes it to the fruit tree. By creating a mulched depression closed to the tree roots located in between the spout outlet and the tree, one can then store this water for slow release to the tree roots! In parallel we create an environment for great fungal communities to thrive which then convert nutrients into food trees can absorb. Also 40% of solid waste stream is mulch so we will diverge some of that waste back into its natural decomposition site. It is important to note that rainwater contains almost no salts compared to city water systems which makes it easier for plants to absorb nutrients.

“Plant the rain first then plant the tree”

Another great example is the use of air conditioning condensate water harvesting. With the island heat effect created by city buildings, air conditioners have become a necessity. These units condensate a great amount of water which by nature of its source comes with no salts which means it can be used to nourish plants. A simple piping system can be implemented to harvest the water and guide it to onsite edible food gardens. On a side note in Austin City Hall there is a man-made waterfall that is fed by air conditioning condensate water!

Simple and creative solutions can often bring remarkable rewards from the natural world. It mostly requires a mental shift on how we view ourselves in relation to our surroundings. We should aim to establish a direct connection with the source of light, water and darkness. When one can see that a rain garden is a net of reconnection with the local landscape, one can see the beauty in all.

“Slow it, spread it and sink it!”

Gerardo

Urban Water Systems with Brad Lancaster